This document presents a project report for a Real Time Question and Answer Platform. The project aims to build an application that allows users to ask and answer questions in real-time via text, voice, video and images. It will route questions to potential experts and provide rewards for fast, accepted answers. The system architecture uses a Play server for multimedia processing and a Meteor JS client and server for the user interface and functionality. The report describes the requirements, design, implementation and testing of the question and answer platform.

1. Real Time Question and Answer Platform
A Project Report
Presented to
The Faculty of the College of
Engineering
San Jose State University
In Partial Fulfillment
Of the Requirements for the Degree
Master of Science in Computer Engineering
Master of Science in Software Engineering
By
Bingyu Li
Kwun Fung Ng
Feiyu Yin
Junchen Zhu
December 2015

2. Copyright © 2015
Bingyu Li
Kwun Fung Ng
Feiyu Yin
Junchen Zhu
ALL RIGHTS RESERVED

3. APPROVED FOR COMPUTER ENGINEERING DEPARTMENT
Dr. Charles Zhang, Project Advisor
Professor Donald Hung, Director, MS Computer Engineering
Dan Harkey, Director, MS Software Engineering
Professor Xiao Su, Department Chair
Charles Zhang
Digitally signed by Charles Zhang
DN: cn=Charles Zhang, o=San Jose State University,
ou=Computer Engineering,
email=charles.zhang@sjsu.edu, c=US
Date: 2015.12.10 08:02:14 -08'00'

4. ABSTRACT
Real Time Question and Answer Platform
By Bingyu Li, Kwun Fung Ng, Feiyu Yin, Junchen Zhu
In our daily life, there are situations that we have questions or problems that needs
to be solved immediately. For example, college students may run into academic problems
that need to be answered right away, but it is not easy to find appropriate answers or a
person for help. There are other situations where a software engineer may struggle with a
compilation error. For this scenario, the solution can be found online, but advice from a
more experienced engineer must be much more helpful.
Even though there are various media available to help people with their daily
questions, it is not guaranteed that their questions can be solved interactively and in real-
time. Also, traditional knowledge sharing media such as textual-based websites are not
clear enough for explaining certain complicated cases. Pictures, audios and videos are
easier for people to read and understand. Thus, multimedia communication with
immediate responses will be a new trend for people to solve their questions.
This project aims on building an application to offer a multimedia communication
platform for users to ask and answer questions instantly via text messages, voice
messages, videos and images, etc. It can route questions to potential experts according to
their categories. The receiver who first offers an accepted answer will get the reward
from the questioner. In this way, the more people involved in using this platform the

5. more efficiently questions can be answered. This platform also includes user's reputation
management module to ensure the quality of the service and to fight against spams.

6. vi
ACKNOWLEDGEMENTS
We would like to express our gratitude to certain individuals who provided many
help, inputs and kind support for this excellent project.
First, we would like to deeply thank towards our advisor Dr. Charles Zhang who
have helped and shared his experience to us. Dr. Zhang gave us a great idea to start with
this Real Time Question and Answer Platform and he guided us to overcome all kinds of
problems. Also, he provided us a lot of resources especially his experience.
Moreover, we would also like to thank the Department of Computer and Software
Engineering at San Jose State University who provided us all resources we needed to
build this project. And the Department of Computer and Software introduced us a group
of world-class professors who lead us and our lovely San Jose State University, to
become highly ranked among the national universities.
Last but not least, we are graduating after completing this project and we would
like to give special thanks to our families who have given us all support including mental,
financial and other valuable support. Without them, our project and the way we achieve
our master’s degree will be much more difficult. We also want to give thanks to all
friends who, in these past two years, have fought with us and worked together toward this
final goal.

7. vii
Table of Contents
Chapter 1
Introduction.................................................................................................. 1
1.1
Project goals and objectives .............................................................................. 1
1.2
Problem and motivation .................................................................................... 2
1.3
Project application and impact .......................................................................... 4
1.4
Project results and expected deliverables.......................................................... 5
1.5
Market research ................................................................................................. 6
1.6
Project report Structure...................................................................................... 7
Chapter 2
Background and Related Work.................................................................. 8
2.1
Background and used technologies ................................................................... 8
2.2
State-of-the-art technologies ............................................................................. 8
2.2.1
Video/audio transcription....................................................................... 8
2.2.2
Parser...................................................................................................... 8
2.2.3
Crowdsourcing ....................................................................................... 9
2.2.4
Routing................................................................................................... 9
2.2.5
Categorization ........................................................................................ 9
2.2.6
Billing................................................................................................... 10
2.3
Literature survey.............................................................................................. 10
Chapter 3
System Requirements and Analysis ......................................................... 13
3.1
Domain and business requirements................................................................. 13
3.2
Customer-oriented requirements ..................................................................... 19
3.3
System (or component) functional requirements ............................................ 23
3.4
System performance and non-functional requirements................................... 24
3.5
System behavior requirements ........................................................................ 25
3.6
Context and interface requirements................................................................. 25
3.7
Technology and resource requirements........................................................... 26
Chapter 4
System Design............................................................................................. 28
4.1
System architecture design.............................................................................. 28
4.1.1
Architecture diagram............................................................................ 28
4.1.2
Play server............................................................................................ 28
4.1.3
Meteor JS client.................................................................................... 31
4.1.4
Meteor JS server................................................................................... 32
4.1.5
Communication between client and servers......................................... 33
4.2
System data and database design..................................................................... 33
4.3
System interface and connectivity design ....................................................... 35
4.3.1
External interfaces to systems/components.......................................... 35
4.4
System user interface design ........................................................................... 35
4.4.1
User interface design............................................................................ 35
4.4.2
User interface operation flow............................................................... 43
4.5
System component API and logic design........................................................ 43
4.5.1
Play server API..................................................................................... 43

8. viii
4.6
Design problems, solutions, and patterns........................................................ 62
Chapter 5
System Implementation............................................................................. 64
5.1
System implementation summary ................................................................... 64
5.2
System implementation issues and resolutions ............................................... 64
5.3
Used technologies and tools ............................................................................ 65
Chapter 6
System Testing and Experiment............................................................... 67
6.1
Testing and experiment scope ......................................................................... 67
6.2
Testing and experimental approaches ............................................................. 68
6.3
Testing and experiment ................................................................................... 68
6.3.1
Testing preparation............................................................................... 68
6.3.2
Testing summary.................................................................................. 69
Chapter 7
Conclusion and Future Work................................................................... 73
7.1
Project summary.............................................................................................. 73
7.2
Future work ..................................................................................................... 74
References........................................................................................................................ 76

9. ix
List of Figures
Figure 1 Activity diagram................................................................................................. 13
Figure 2 Process decomposition diagram overall ............................................................. 14
Figure 3 Process decomposition diagram of posting a question....................................... 14
Figure 4 Process decomposition diagram of posting an answer....................................... 15
Figure 5 Process decomposition diagram of changing personal setting........................... 16
Figure 6 Class diagram ..................................................................................................... 17
Figure 7 State of machine diagram of posting a question................................................. 18
Figure 8 State of machine diagram of posting an answer................................................. 19
Figure 9 System architecture ............................................................................................ 28
Figure 10 ER diagram....................................................................................................... 34
Figure 11 External interface diagrams.............................................................................. 35
Figure 12 Chatting page.................................................................................................... 36
Figure 13 Notifications page............................................................................................. 36
Figure 14 Landing page .................................................................................................... 37
Figure 15 Questions asked page ....................................................................................... 37
Figure 16 Questions answered page ................................................................................. 38
Figure 17 Question creation page ..................................................................................... 38
Figure 18 Question detail page ......................................................................................... 39
Figure 19 Answer detail page ........................................................................................... 39
Figure 20 Closed question page........................................................................................ 40
Figure 21 User profile page .............................................................................................. 40
Figure 22 User signup page .............................................................................................. 41
Figure 23 User login page................................................................................................. 41
Figure 24 Notification on the top bar................................................................................ 42
Figure 25 Notification in the notification list ................................................................... 42
Figure 26 GUI flow diagram............................................................................................. 43
Figure 27 API diagram 1................................................................................................... 44
Figure 28 API diagram 2................................................................................................... 44
Figure 29 API diagram 3................................................................................................... 45
Figure 30 API diagram 4................................................................................................... 45
Figure 31 API diagram 5................................................................................................... 46
Figure 32 API diagram 6................................................................................................... 46
Figure 33 API diagram 7................................................................................................... 47
Figure 34 API diagram 8................................................................................................... 47
Figure 35 API diagram 9................................................................................................... 48
Figure 36 API diagram 10................................................................................................. 49
Figure 37 API diagram 11................................................................................................. 49
Figure 38 API diagram 12................................................................................................. 50
Figure 39 API diagram 13................................................................................................. 50
Figure 40 API diagram 14................................................................................................. 51
Figure 41 API diagram 15................................................................................................. 52
Figure 42 API diagram 16................................................................................................. 52

10. x
Figure 43 API diagram 17................................................................................................. 53
Figure 44 API diagram 18................................................................................................. 53
Figure 45 API diagram 19................................................................................................. 54
Figure 46 API diagram 20................................................................................................. 55
Figure 47 API diagram 21................................................................................................. 55
Figure 48 API diagram 22................................................................................................. 56
Figure 49 API diagram 23................................................................................................. 56
Figure 50 API diagram 24................................................................................................. 57
Figure 51 API diagram 25................................................................................................. 57
Figure 52 API diagram 26................................................................................................. 58
Figure 53 API diagram 27................................................................................................. 58
Figure 54 API diagram 28................................................................................................. 59
Figure 55 API diagram 29................................................................................................. 59
Figure 56 API diagram 30................................................................................................. 60
Figure 57 API diagram 31................................................................................................. 60
Figure 58 API diagram 32................................................................................................. 61
Figure 59 API diagram 33................................................................................................. 62
Figure 60 API diagram 34................................................................................................. 62

11. xi
List of Tables
Table 1 Comparison with traditional Q&A ........................................................................ 4
Table 2 User login............................................................................................................. 20
Table 3 User enrollment.................................................................................................... 20
Table 4 Change personal setting....................................................................................... 20
Table 5 Post a question ..................................................................................................... 21
Table 6 View post question............................................................................................... 21
Table 7 Message chat with expert..................................................................................... 21
Table 8 Video chat with expert......................................................................................... 22
Table 8 Post an answer to a question................................................................................ 22
Table 10 View post answers ............................................................................................. 22
Table 11 Choose best answer............................................................................................ 23
Table 12 Functional requirements .................................................................................... 24
Table 13 Non-functional requirements ............................................................................. 25
Table 14 System behavior requirements........................................................................... 25
Table 15 UI requirement design ....................................................................................... 26
Table 16 Environments..................................................................................................... 26
Table 17 Server technologies............................................................................................ 27
Table 18 Client technologies ............................................................................................ 27
Table 19 Development tools ............................................................................................. 27
Table 20 System implementation issues and resolutions.................................................. 65
Table 21 Used server technologies ................................................................................... 65
Table 22 Used client technologies .................................................................................... 66
Table 23 Development tools ............................................................................................. 66
Table 24 Testing scope ..................................................................................................... 67
Table 25 Testing approaches ............................................................................................ 68

12. 1
Chapter 1 Introduction
This project is to design and develop a new question and answer (Q&A)
web/mobile application for users to communicate with experts and to get a best answer
for their questions. This chapter depicts goals and objectives of our project, and describes
the problems we have met and how we solved as well as motivation and needs. It also
presents the application and result of our project. Last, market research and report
structure is mentioned in this chapter.
1.1 Project goals and objectives
This project aims to offer a platform for users to ask and answer questions and
communicate with experts in concerned areas. It can cover topics from a homework
question of a course at San Jose State University to an auto repair problem, as long as
there are users experienced in different fields. Users can students, professors, patients,
doctors, engineers, and workers, etc. In a word, users can be anyone who has a
smartphone or a computer. Instead of looking for experts to solve their questions, users
only need to post their questions on our platform with any form they prefer, voice
message, text message, or an image, and wait for their answer. Our achievements can be
succeed while users can obtain the benefits from the Q&A applications as the following:
• Instant notification for users (experts) after other users posted their
questions. The questions will first enter into our routing system and they
will be sent to certain users (expert). This can decrease responses times
and users (expert) who know the solutions can post their comments and

13. 2
answers immediately. Thus, the users who ask questions can obtain the
most suitable answers in shorter time.
• When users are discussing some complicating questions, they cannot only
use text but also drawing and videos to explain and answer their questions.
Graphics and videos can reduce the degree of abstract for the questions
and users can have higher efficiency to understand concepts.
• Our application is integrated with famous drawing and videoconference
API such as Google hangout. Thus, most users will find it is very easy to
use and they can just install, register and ask their questions in our
application.
1.2 Problem and motivation
The Real Time Question and Answer Platform is an efficient system for users to
post their questions and sharing their thoughts and answers. Users can ask any categories
questions such as academic, medical or any problems happens in their daily life. For
each question, it may involve couple categories and there could be multiple solutions for
that question.
An efficient system can enhance users’ life quality and also reduce their waiting
time. About twenty years ago, Yahoo and Google just started, these two search engines
were most reliable and efficient system in our world. These two search engines changed
people's life style. People who used to search their problems from books or mailed their
questions to some experts with hours to week’s response time became typing their
problems on their computers with less than a second response time. What we want to do

14. 3
is similar to this concept and we would like to deliver an efficient Q&A system to users
and they can have less waiting time and more comments and answers to their problems.
An efficient system can be described in one word “fast”. We need to create a
system fast enough for users and they would feel comfortable to ask. Since we have many
categories and each category might correlate to the others, we needed to figure out how to
do a better routing job. For example, after an user asked his question, our system need to
route his question to other expert users who subscribed to related categories in a very
short period so that the user would not need to wait for long time for his answers.
When most developers start their development for mobile applications, they
would have the same question that if they should build Android or iOS application first.
Both Android and iOS are popular in the mobile devices market. If they don’t have
sufficient resources to build both together, they might lose the other side customers.
Thus, we have found that we need to choose a better way to take care both OS users.
Finally, we chose Meteor as our system framework and it can create web service while it
can also provide both mobile applications at the same time.
On the other hand, there may be thousands questions may be posted on traditional
webs or forums. As we are frequent users of couple forums, we noticed that some
questions we may miss due to huge volume of questions may show on the same page and
that means our expert users may miss some questions they may be interested in or
experienced with. So this could finally lead to fewer answers and longer wait time for our
users. So as to solve this problem, we have developed a routing system for our expert
users. Expert users can subscribe to their expertise categories or keywords and our system

15. 4
will send notifications to them so they can answer or view the questions immediately.
This can also reduce their time to search on our web site.
Real Time Q&A
Traditional Q&A
(e.g. Stack Overflow)
User interface
Android, iOS, Web
browsers
Only Web browsers
Text reply questions Yes Yes
Pictures upload Yes Only a couple of websites support
Instant chat Yes No
Video call Yes No
Notification for new
questions
Yes, actively send to
users’ mobile devices
No
Notification for new
answers
Yes, actively send to
users’ mobile devices
Yes but is passively that users
have to login to see them
Communication
media
4 different ways 1 or may be 2 different ways
Efficiency for
waiting answers
Fastest
Slow and have to wait and check
by users
Rating answers
system
Yes Yes
Rating for expert
users
Yes Some websites may have it
Table 1 Comparison with traditional Q&A
1.3 Project application and impact
The purpose of this project is to provide an efficient solution for an individual
user who has a question that is expected to answer instantly. It is easy for users to install
this app on their smartphone or open it on their computer. Once the user registers an
account, they can start asking questions. It is very convenient since users do not need to
go to visit someone who may know the answer. It not only saves time but also collects

16. 5
more comprehensive answers to a question from different experts. It plays like users go
anywhere with helpers in hand as long as they have data access or Internet connection.
This application can greatly improve users’ productivity and efficiency working
on a certain topic. They do not need to make an appointment with people who they want
to get an answer. And the experts can answer questions during their spare time with a
reward from who ask the question once theirs are picked as best answer. So it is a win-
win game for both users who ask questions and answer questions.
The platform is designed in a scalable and extensible way so that anyone can
configure and add new features easily to improve this application. In addition, the bigger
users database it has, the more benefits and popularity can be gained by the users.
1.4 Project results and expected deliverables
Our project delivers a question and answer platform which can be used on a
computer as a website or on a Android or iOS smartphone as a mobile application. No
technical skill is required for using this platform.
The project has following deliverables:
• A project report that describes project plan and background, system
requirements and analysis, system design and implementation, and system
testing.
• Well-designed mobile application for Android and iOS.
• Well-designed website.
• Application user guide.

17. 6
• Environment setup guide.
• RESTful APIs specification.
1.5 Market research
Nowadays, there are many choices for us to solve our problems such as watching
online tutorial videos, posting their questions online and waiting for replies. For general
questions, we may be able to search the online such as YouTube where people already
posted their solutions. However, for some specific questions or some questions required
professional knowledge, we would need to post on some forums or Q&A websites and
wait for replies.
The first Q&A online service was invented in 1992. After a decade, numbers of
popular Q&A websites increased from less than 10 to more than 40 sites today. The rapid
increment of websites also brought a huge number increased in users side. The most
popular like Ask.com, Stack Exchange Network and Yahoo! Answer use crowdsourcing
to solve users’ questions posted. After users posted their problem on the Q&A forum or
websites, other users can view the questions and post their solutions under the questions
they are answering. Some websites such as Yahoo! Answer and Stackoverflow.com have
a feature that all users can rate the best answers and give scores (rewards) for the
solutions.
Although all Q&A websites can provide convenient platforms for users to solve
their problems, there are some improvements can enhance the system efficiency. After
users posted their questions, users have to wait for replies and also wait for other user
rating the solutions. For some urgent cases, users would like to get immediate responses

18. 7
such as their cars have weird sound coming out from the engine while driving. On the
other hand, most Q&A websites are textual base websites which user can only input text
but not graphics or videos. For some complicated questions such as logical questions, text
may not be sufficient for explanation.
1.6 Project report Structure
This report begins with brief introduction of our project, and background research
like studies on market share and existing technologies as well as literature review of
related subjects. Then system requirements and analysis are specified in Chapter 3,
including both business and customer sides, functional, behavioral and performance
aspects, and interface and technology viewpoint. Chapter 4 presents system architecture
design and database schema, followed by interface design, API components and logic
design. Problems and solutions of system design are also mentioned in this section.
Chapter 5 describes system implementation and used technologies and tools for this
project. Chapter 6 reports relevant testing and experiment we have done for this project to
make sure the platform works well on different operating systems. Last chapter shows
our project achievements and conclusions, and potential future work to improve this
project.

19. 8
Chapter 2 Background and Related Work
This chapter describes the background of our project and current technologies and
literature that have been used and studied in the area of question and answer platform.
2.1 Background and used technologies
Q&A websites are very popular and many people are using them for solving their
daily questions. These Q&A websites can provide convenient platforms for users to ask
their questions. Thus, what are the precious things our application provided to achieve the
goals we set? Time is precious and valuable for everyone, so we will focus on efficiency.
And we focus on some technical techniques used for our project, transcription, parser,
crowdsourcing, routing, categorization and billing.
2.2 State-of-the-art technologies
2.2.1 Video/audio transcription
Video/ audio transcription or speech recognition software component assists in
the dialogue or conversion of human speech into text transcript. So users only need to
hold their phones and record voice or video instead of typing text, which saves them a lot
of time and brings convenience. Users can still talk to their phone even with their hands
full with other work. There are some popular transcription tools in the market like
Dragon Dictation, Evernote for Android, and Voice Assistant.
2.2.2 Parser
A parser is a software component that receives input data, then analyzes its
syntactic structure and breaks them up into units that can be managed by other software
components. Stanford University [1] has done a lot of research on natural language

20. 9
parsers and has released several types of parsers, such as shift-reduce constituency parser
[2], compositional vector grammar parser [3] and neural-network dependency parser [4].
2.2.3 Crowdsourcing
Crowdsourcing describes a new web-based business model that harnesses the
creative solutions of a distributed network of individuals through what amounts to an
open call for proposals [5]. Crowdsourcing model significantly reduces business cost by
gathering expertise as labor powers so that they can help users to solve their questions.
Taking the t-shirt selling website Threadless as an example, its sales in 2006 hit $18
million with profits occupying one third and the number of its employees was less than
20.
2.2.4 Routing
Routing is the process of selecting the best paths in a network to move a packet of
data from source to destination. The efficiency of processing questions to experts high
depends on routing technology used for our project. It transfers a question among experts
in search of the potential answers to solve the question.
2.2.5 Categorization
Categorization is used for categorize questions into different classification.
Categorization can increase the efficiency for searching answers and reduce the response
time. We will implement this part for users choose their questions categories and our
backend system will do further categorization such as using questions keywords.

21. 10
2.2.6 Billing
Mobile billing software component makes it easier and more convenient for users
to purchase merchandise, make payments and track their transaction history on their
smartphones. There are various commercial applications such as Android in-app billing
API, Apple Pay, PayPal Mobile SDKs, etc.
2.3 Literature survey
The explosion of data has motivated the demand for efficient and cost-effective
strategies for knowledge discovery and data mining. Question answering technologies
has gained lots of attention because of the improvement on machines technologies,
natural language and cloud computing [6-8].
A question and answering system aims to “extract” the best matching answer to a
question from all kinds of resources. Traditionally, answering systems do not directly
answer a question but find a matched answer in their database or from Internet resources
by certain algorithm. This is not an easy task of mapping an answer to a question, for
example, users may ask a question in different ways but the answer is going to be the
same. People who are working in this area have come up with various solutions such as
dictionaries, syntactic parsing, semantic relations, entity extraction and so on [9-11].
START natural language question and answering system is the world's first web-based
question answering system. Till now START develops to answer millions of questions in
English in the fields of geography, science and reference, arts and entertainment, and
history and culture. Kwok et al. [12] stated MULDER as the first general purpose, fully
automated question-answering system available on the Internet. It sends users’ queries to

22. 11
Google search engine and retrieves high-quality answers from search results by using
several language parsers and heuristics [13]. Major components of a document-
collection-based automated Q&A system were mentioned by Kwok, which included
retrieval engine, query formulation and answer extraction.
It is hard to guarantee the accuracy of answers even though many solutions have
been applied. Question answering websites are an alternative for people to look for
answers especially more complicated ones. Viewers can answer posted questions, and all
answers are evaluated. Answer evaluated with highest score is chosen as the best answer.
Question answering website has better accuracy on results and can handle more
complicated and professional questions comparing to question answering system, but the
trade off is longer waiting time. Stack Overflow is a Q&A website built for programmers.
Categories are classified into different programming languages and programming related
fields. Majority users are programmers or people who are learning programming. Users
are rewarded with reputation and badges, so others can review their activity level on this
platform. Low quality questions are closed to improve. As of April 2014, Stack Overflow
has over 2,700,000 registered users and more than 7,100,000 questions.
Now new question answering websites provide real-time answer services.
Registered users may select one expertise from the website (who are not website
employees but also users) and start a one-to-one texture, audio or video question and
answering section. The user can pay certain amount of money. These websites are built
for people with more complicated or professional questions since billing is involved in

23. 12
this kind of system model. Codementor is another coding Q&A website that provides
one to one service with a mentor expert for debugging, code review services through
screen shard video and text chat. Typically a mentor’s service rate starts at $10/ 15 min.
Baidu Knows is a Q&A website provided by Baidu.com, the top one search
engine in China. Benefited from Baidu search engine, Baidu knows is the most widely
used Q&A website. The business model that combine search engine and Q&A website
makes each member a supplier and consumer of the knowledge which is called collective
intelligence.

24. 13
Chapter 3 System Requirements and Analysis
3.1 Domain and business requirements
Our application aims to users who have questions that needed to be solved
immediately and also expertise who want to help others solving their problems. In order
to connect question askers and expertise we developed this Q&A platform.
Base on our requirements, we designed our application the way below.
Figure 1 Activity diagram

25. 14
Figure 2 Process decomposition diagram overall
Figure 3 Process decomposition diagram of posting a question

26. 15
Figure 4 Process decomposition diagram of posting an answer

27. 16
Figure 5 Process decomposition diagram of changing personal setting

28. 17
Figure 6 Class diagram

29. 18
Figure 7 State of machine diagram of posting a question

30. 19
Figure 8 State of machine diagram of posting an answer
3.2 Customer-oriented requirements
Use Case Tables are shown here.

31. 20
Use case name User login
Use case id 1
Actors All users
Description Users use email and password to login to
System.
Alternative If user is not enrolled, account enrollment is
required. If email and password combination is
not right login process prohibited.
Table 2 User login
Use case name User enrollment
Use case id 2
Actors All users
Description User needs to provide email, first name, last
name and password to create user account.
Alternative If email is duplicated from other users,
enrollment fails. User needs to provide another
email address.
Table 3 User enrollment
Use case name Change personal setting
Use case id 3
Actors Logged in users
Description User may change first name, last name,
password and tags
Alternative Null
Table 4 Change personal setting

32. 21
Use case name Post a question
Use case id 4
Actors Logged in users with question
Description User provides question title, content, upload
images, and take pictures to post a question.
Alternative Null
Table 5 Post a question
Table 6 View post question
Table 7 Message chat with expert
Use case name View posted questions
Use case id 5
Actors Logged users with posted questions
Description Select posted questions to view details and
answers
Alternative Null
Use case name Message chat with expert
Use case id 6
Actors Logged users with posted questions
Description User select an expert that answered the
question to start a message chat
Alternative Expert declines the message chat request.

33. 22
Use case name Video chat with answerer
Use case id 7
Actors Logged users with posted questions
Description User select expert that answered question to
start a video chat
Alternative Expert declines the video chat request.
Table 8 Video chat with expert
Use case name Post answer to a question
Use case id 8
Actors Logged in Pro
Description Pro answers a question with providing textual
messages, uploading image or take picture to
answer question.
Alternative Null
Table 9 Post an answer to a question
Use case name View posted answers
Use case id 9
Actors Logged in Pro
Description Pro views posted answers from a list.
Alternative No posted answers.
Table 10 View post answers

34. 23
Use case name Choose best answer
Use case id 10
Actors Logged in question asker
Description Question asker chooses one best answer
from posted answer list.
Alternative No answer posted or no satisfied answer.
Table 11 Choose best answer
3.3 System (or component) functional requirements
ID Description Input Output
FR1 The system shall
provide user login
functionality
User email address and
matching password
If error, returns login fails;
if succeed, response user
information.
FR2 The system shall
provide user account
creation functionality
User email address,
password, first name, last
name
If email duplicates, enroll
fails, if successes account
is created.
FR3 The system shall
provide user personal
setting update
functionality
User updates personal
information
If error, update fails;
If successes profile is
updated.
FR4 The system shall
provide question review
functionality
User selects question to
review
Display selected question
details.
FR5 The system shall
provide question post
functionality
Question title, question
content, credit, uploaded
images and take pictures
If succeed, redirects to
posted question details.
FR6 The system shall
provide message chat
between question poster
and answerer
Question poster request
message with answerer
If answerer accepted,
request starts chatting, if
rejected, request fails.

35. 24
FR6 The system shall
provide video chat
between question poster
and answerer
Question poster request
video chat with answerer
If answerer accepted,
request starts chatting, if
rejected, request fails.
FR7 The system shall
provide question
routing to proper
specialist.
Posting questions Posted question is routed
to proper specialist
FR8 The system shall
provide answer post
functionality.
Answering content,
uploading images, taking
pictures.
If successes redirects to
posted answer details.
FR9 The system shall
provide all answers
User selects answer to
review
Display selected answer
details.
FR10 The system shall
provide push
notification
When question is posted,
new answer is posted,
answer is selected as best
answer; when message chat
request is posted, video
chat request is posted.
Notification is pushed to
client.
Table 12 Functional requirements
3.4 System performance and non-functional requirements
NFR01 Response time
After users post their questions, the dispatching process
should take less than 1 second. After users post questions,
the question shall be routed to expertise within 5s.
NF02 Accuracy
The percentage that questions be routed to proper users is
greater than 99.9%.
NFR03 Reliability
The platform should ensure that users’ questions and
answers are dispatched without any information losing.
The platform should be still available when server load is
heavy.
NFR04 Security
The platform should keep users’ personal information
secure. The platform should keep every question and

36. 25
answer confidential.
NFR05 Capability
The system server should provide more than 1000 users to
post questions and answers at same time without fails.
Table 13 Non-functional requirements
3.5 System behavior requirements
System Consistency System should provide consistency that do not shut down and
response all requests properly
Error Handling System should cache errors and exceptions and errors and hand
each of them properly
Error logging System should log unhandled errors and exceptions
Database backup System should backup database periodically
Activities logging System should log main activities
Table 14 System behavior requirements
3.6 Context and interface requirements
User interface is an important part of our application. We want to make our
application user friendly, so that all users can have simple pages but with sophisticated
functionalities. In order to achieve this goal, we designed our UI based on below
requirements.
UI Requirement Description
Suitability
Layout of each page should appropriately display functions
both effectively and efficiently.
Controllability User should be able to fully control of this application that
all functions are well described.

37. 26
Conformity All pages are designed simple and direct that users can find
needed functions easily and feel comfort to use this
application.
Suitability Ignoring the differences of each user, this application is
suitable for all users.
Table 15 UI requirement design
Environment
Local / EC2 Java environment Play framework runtime environment
Local / EC2 MySQL environment MySQL database environment
Local / EC2 MongoDB environment MongoDB environment
Local / EC2 Android development
toolkit environment
Client development /test environment
Table 16 Environments
3.7 Technology and resource requirements
Server Technologies Description
AWS EC2 Both play server and meteor are implemented on Amazon
EC2 cloud servers. AWS EC2 provides on demand host
configuration.
MySQL MySQL is used for play server database, since it’s an
open source storage and provides lots of great features.
Play Framework Play Framework makes it easy to build web applications
with Java.
MeteorJS Provides full stack development for both server and client
with JavaScript.

38. 27
MongoDB Database associated with meteor server.
Table 17 Server technologies
Client Technologies Description
HTML5/CSS Thanks to MeteorJS and Cordova, Html5 and CSS can be
used to development mobile app user interface
jQuery JavaScript library to provide client-side activities.
Cordova JavaScript app development platform which build
JavaScript app into mobile native app
Ionic
Beautiful and well developed open source front-end SDK
for developing mobile apps with web technologies
PhoneGap push notification Implement push notification for Android app, iOS app,
and web app using JavaScript.
Table 18 Client technologies
Development Tools Description
Eclipse IDE for java development
IntelliJ IDE for both java and JavaScript development
Sublime Popular text editor
Android SKD Studio Android emulator and package management
Table 19 Development tools

39. 28
Chapter 4 System Design
4.1 System architecture design
4.1.1 Architecture diagram
Below is the architecture of our system:
Figure 9 System architecture
Generally, there are two servers and one client in our system. Each server and
client has a dedicated database.
4.1.2 Play server
Play is the server that handles the main logic and data modeling of the system. It
is written in Java. The reason why we choose Play is that it is an asynchronized server
which will not be blocked on IO requests, and it has many built in Java modules that we
are familiar with such as JPA, Ebean, Global settings and so on. There are basically eight
components in this server: user component, question component, answer component,

40. 29
notification component, question routing component, category component, authentication
component and common utility component.
• User component:
User component manages user profiles, and user status such as online or offline.
• Question component:
Question component manages all the questions in the system, such question
creation, question update, question deletion, question status management and so on.
• Answer component:
Answer component manages all the answer in the system, such as answer
creation, answer update, answer deletion, answer status management and so on.
• Notification component:
Notification component manages all the notifications in the system. There are four
kinds of notifications: new question notification (which tells users they get new
questions), new answer notification (which tells users they get new answers), best answer
notification (which tells users their answers are chosen as the best answer) and chatting
request notification (which tells users that someone want to chat to them). This
component manages the notification creation, notification deletion, notification status
management and so on.
• Question routing component:
Question routing component routs the questions to the proper users. Every
question should fall into at least one category and users should have at least one
specialization. In the first step of question routing, the system will find the persons who

41. 30
has the specialization that falls into the questions categories. The next step is to filter out
the users who are not available currently, and the rest of the users will be the candidates
of the questions. Thirdly, system will rank the candidates according to their experience.
Experience is an integer field of User entity that keeps track of how active a user is in this
platform. Ask questions or answer questions both increase user’s experience. From the
ranked candidates, we get a certain number of them and rout the question to them.
• Category component:
Category component manages all categories in the system, such as category
creation, category update, category deletion and so on.
• Authentication component:
Authentication component authenticates the data transferred between client and
server. It also manages the functionalities such as user signup, user signin, user sign out,
client hear beat handling and so on.
• Common utility component:
Common utility component provides the functionalities that other components
need in common, such current timestamp, logging, and so on.
• Database for Play server:
Play server has a dedicated MySQL database connected, which stores all the
information.

42. 31
4.1.3 Meteor JS client
Meteor JS client is the client part of our system. The reason why we choose
Meteor JS is that by using Meteor JS, we are able to build Android native app, iOS native
app and web app using a single source code written in JavaScript. There are mainly four
components in Meteor JS client: user authentication and profile settings component,
question component, answer component and notification component.
• User authentication and profile settings component:
User authentication and profile settings component manages user login, user
signup and user profile information logic from the client side. It also provides the GUI of
login page, and sign up page.
• Question component:
Question component manages all user questions logic such as question creation,
question update on client side. It also provides the GUI of all question page, question
creation page, question update page, question detail page.
• Answer component:
Answer component manages all user questions logic such as Answer creation,
Answer update on client side. It also provides all the GUI of Answer page, Answer
creation page, Answer update page, and Answer detail page.
• Notification component:
Notification component manages all user Notification logic such as notification
retrieving on client side. It also provides the GUI of all Notification page.
• Database for Meteor JS client:

43. 32
Play server has a Mongo DB database connected, which stores all temporary
information the client needs when running.
4.1.4 Meteor JS server
There is another server which is written using Meteor JS framework. The reason
we need another server is that it facilitates the image uploading functionality, push
notification functionality and live chatting functionality. It is more intuitive and
convenient to implement these functionalities using the same framework as the Meteor JS
client. There are three components in this server: image component, chatting component
and push notification component.
• Image component:
Image component provides the client with the image uploading, image
downloading functionality. These functionalities are used in questions and answers.
• Chatting component:
Chatting component provides the client with the live chatting functionality.
• Push notification component:
Push notification component provides the client with the push notification
functionality. There will be push notification when there is a new question for an user, or
an new answer for an user, or someone’s answer has been chosen as the best answer, or
one user wants to chat to another user. User can only get push notification when the app
is in background mode.
• Database for Meteor JS server:

44. 33
Play server has a Mongo DB database connected, which stores all the information
about images, chatting and push notifications.
4.1.5 Communication between client and servers
For the Communication between client and servers, the system is using RESTful
API, which send JSON data as the payload.
4.2 System data and database design
Below is the ER diagram of our system on Play server.

45. 34
Figure 10 ER diagram

46. 35
4.3 System interface and connectivity design
4.3.1 External interfaces to systems/components
Below is the diagram of the interfaces of our platform and APN and GCM. This
system only uses APN and GCM as third party component. APN and GCM help the push
notification functionality in the system.
Figure 11 External interface diagrams
4.4 System user interface design
4.4.1 User interface design
Because we used Meteor JS framework, there are totally three kinds of clients:
Android, iOS and web. The GUIs are all the same among these three clients. Here we
only show the GUI presenting on Android platform. Below are the GUI of all the pages
on the mobile app client.

47. 36
Figure 12 Chatting page
Figure 13 Notifications page

48. 37
Figure 14 Landing page
Figure 15 Questions asked page

49. 38
Figure 16 Questions answered page
Figure 17 Question creation page

50. 39
Figure 18 Question detail page
Figure 19 Answer detail page

51. 40
Figure 20 Closed question page
Figure 21 User profile page

52. 41
Figure 22 User signup page
Figure 23 User login page

53. 42
Figure 24 Notification on the top bar
Figure 25 Notification in the notification list

54. 43
4.4.2 User interface operation flow
Below diagram shows the flow of the above user interfaces.
Figure 26 GUI flow diagram
4.5 System component API and logic design
4.5.1 Play server API
We used the RESTful API as the main communication protocol between the Play
server and Meteor JS client. Below are the details about these APIs:
HTTP Method: GET
Request URL: /
Request Data: Null
Response: OK (200) for logged in user; bad request (400) for user not logged in.
Comments: Request the main page; return login page if user is not logged in or landing
page if user is logged in.
Diagram:

55. 44
Figure 27 API diagram 1
HTTP Method: POST
Request URL: /signin
Request Data:
Format JSON
Structure {“email” : (Long), “password”: (String) }
Response: OK (200) for correct credentials; bad request (400) for wrong credentials.
Comments: Send this request to login. Data will be authenticated by the server.
Diagram:
Figure 28 API diagram 2
HTTP Method: POST
Request URL: /signup
Request Data:
Format: JSON
Structure: {"email": (String), "password": (String), "firstName": (String) ,
"lastName": (String), "uMId": (String)}
Response: OK (200) for signup successfully; bad request (400) for unsuccessful signup.
Comments: Send this request to signup a new account. Data will be authenticated by the
server.

56. 45
Diagram:
Figure 29 API diagram 3
HTTP Method: GET
Request URL: /heartbeat/:userId
Request Data: null
Response: Bad request (404) if user does not exist. OK (200) for heartbeat received; bad
request (400) for fail to receive the heartbeat.
Comments: Send this request periodically to let server know the specific user is still
online.
Diagram:
Figure 30 API diagram 4
HTTP Method: GET
Request URL: /logoff/:userId
Request Data: null
Response: Bad request (404) if user does not exist. OK (200) for logoff successfully; bad
request (400) for fail to logoff the user.
Comments: Send this request to log an user off.
Diagram:

57. 46
Figure 31 API diagram 5
HTTP Method: GET
Request URL: /isonline/:userId
Request Data: null
Response:
Bad request (404) if user does not exist
Format: JSON
Structure: {“result”: (boolean)}
Comments: Send this request to test if a user is still online or not.
Diagram:
Figure 32 API diagram 6
HTTP Method: GET
Request URL: /chat
Request Data:
Format: JSON
Structure: {“fUId”: (String), “tUId”: (String), “uuid”: (String), “aId”: (String)}
Response: OK (200) if chatting request is handled successfully; bad request (400) if fail
to handle the chatting request.

58. 47
Comments: Send this request to start to send a chatting request to another user via the
server.
Diagram:
Figure 33 API diagram 7
HTTP Method: GET
Request URL: /users/:userId
Request Data: null
Response:
Bad request (404) if user does not exist.
otherwise
Format: JSON
Structure: {“uId”: (String), “uMId”: (String), “firstName”: (String), “LastName”:
(String), “email”: (String), “credit”: (Integer), “exp”: (Integer), “online”: (boolean),
“lastActiveTime”: (Long)}
Comments: Send this request to get the information of a specific user;
Diagram:
Figure 34 API diagram 8

59. 48
HTTP Method: GET
Request URL: /userbyumid/:umid
Request Data: null
Response:
Bad request (404) if user does not exist.
otherwise
Format: JSON
Structure: {“uId”: (String), “uMId”: (String), “firstName”: (String), “LastName”:
(String), “email”: (String), “credit”: (Integer), “exp”: (Integer), “online”: (boolean),
“lastActiveTime”: (Long)}
Comments: Send this request to retrieve user information based on the uMId provided.
uMId is the Id that generated by the meteor client.
Diagram:
Figure 35 API diagram 9
HTTP Method: PUT
Request URL: /users/:userId
Request Data:
Format: JSON
Structure: {"email": (String), "password": (String), "firstName": (String) ,
"lastName": (String), “cIds”: (Array of Integers), }
Response:
Resource not found (404) if user does not exist
otherwise OK (200) if user information updated successfully; bad request (400) if
fail to update the user information.
Comments: Send this request to update the existing user information
Diagram:

60. 49
Figure 36 API diagram 10
HTTP Method: DELETE
Request URL: /users/:userId
Request Data: null
Response:
Resource not found (404) if user does not exist
otherwise OK (200) if delete user successfully; bad request (400) if fail to delete
the user.
Comments: Send this request to delete the user from the system.
Diagram:
Figure 37 API diagram 11
HTTP Method: POST
Request URL: /questions
Request Data:
Format: JSON
Structure: {"uId": (Long), "title": (String), "content": (String), "credit": (Integer),
"UUID": (String), "cIds": (JSON array of Integers), "imageUrls": (JSON array of
Strings)}

61. 50
Response: OK (200) if question created successfully; bad request (400) if fail to create
the question.
Comments: Send this request to create a new quest based on the information provided.
Diagram:
Figure 38 API diagram 12
HTTP Method: GET
Request URL: /questions/:qId
Request Data: null
Response:
Resource not found (404) if question does not exist
otherwise
Format: Json
Structure: {“qId”: (Long), "uId": (Long), "title": (String), "content": (String),
"credit": (Integer), "UUID": (String), "cIds": (JSON array of Integers), "imageUrls":
(JSON array of Strings), “bestAnswer”: (Long), “isOpen”: (boolean), “hasImage”:
(boolean), “hasVoice”: (boolean), “createdTime”: (String), “createdDate”: (String),
“closeTime”: (String), “closeDate”: (String)}
Comments: Send this request to retrieve the information of a specific question.
Diagram:
Figure 39 API diagram 13

62. 51
HTTP Method: GET
Request URL: /userquestions/:userId
Request Data: null
Response:
Resource not found (404) if user does not exist
otherwise
Format: Json
Structure: JSON array of {“qId”: (Long), "uId": (Long), "title": (String),
"content": (String), "credit": (Integer), "UUID": (String), "cIds": (JSON array of
Integers), "imageUrls": (JSON array of Strings), “bestAnswer”: (Long), “isOpen”:
(boolean), “hasImage”: (boolean), “hasVoice”: (boolean), “createdTime”: (String),
“createdDate”: (String), “closeTime”: (String), “closeDate”: (String)}
Comments: Send this request to get all questions that are asked by the specific user.
Diagram:
Figure 40 API diagram 14
HTTP Method: GET
Request URL: /answerquestions/:userId
Request Data: null
Response:
Resource not found (404) if user does not exist
otherwise
Format: Json
Structure: JSON array of {“qId”: (Long), "uId": (Long), "title": (String),
"content": (String), "credit": (Integer), "UUID": (String), "cIds": (JSON array of
Integers), "imageUrls": (JSON array of Strings), “bestAnswer”: (Long), “isOpen”:
(boolean), “hasImage”: (boolean), “hasVoice”: (boolean), “createdTime”: (String),
“createdDate”: (String), “closeTime”: (String), “closeDate”: (String)}

63. 52
Comments: Send this request to get all questions answered by the user
Diagram:
Figure 41 API diagram 15
HTTP Method: PUT
Request URL: /questions/:qId
Request Data:
Format: JSON
Structure: {"title": (String), "content": (String), "credit": (Integer), "cIds": (JSON
array of Integers), "imageUrls": (JSON array of Strings), “bestAnswer”: (Long)}
Response: Resource not found (404) if question does not exist. OK (200) if question is
updated successfully, or bad request (400) if fail to update the question.
Comments: Send this request to update an existing question.
Diagram:
Figure 42 API diagram 16
HTTP Method: DELETE
Request URL: /questions/:qId
Request Data: null

64. 53
Response: Resource not found (404) if question does not exist; OK (200) if question
deleted successfully; Bad request (400) if fail to delete the question.
Comments: Send this request to delete an existing question.
Diagram:
Figure 43 API diagram 17
HTTP Method: POST
Request URL: /answers
Request Data:
Format: JSON
Structure: {"uId": (Long), "qId": (Long), "content": (String), "isBest": (boolean),
"views": (Integer), "likes": (Integer)}
Response: OK(200) if answer created successfully or bad request (400) if fail to create
the answer.
Comments: Send this request to create an answer for a specific question.
Diagram:
Figure 44 API diagram 18
HTTP Method: GET
Request URL: /answers/:id
Request Data: null

65. 54
Response:
Resource not found (404) if answer does not exist
otherwise
Format: JSON
Structure: {“aId”: (Long), “qId”: (Long), “content”: (String), “isBest”: (boolean),
“likes”: (Integer), “views”: (Integer), “hasImage”: (boolean), “hasVoice”: (boolean),
“uId”: (Long)}
Comments: Send this request to retrieve the information about an answer.
Diagram:
Figure 45 API diagram 19
HTTP Method: GET
Request URL: /questionsanswer/:qId
Request Data: Null
Response:
Resource not found (404) if question does not exist
Format: JSON
Structure: Array of {“aId”: (Long), “qId”: (Long), “content”: (String), “isBest”:
(boolean), “likes”: (Integer), “views”: (Integer), “hasImage”: (boolean), “hasVoice”:
(boolean), “uId”: (Long)}
Comments: Send this request to get all answers to a particular question.
Diagram:

66. 55
Figure 46 API diagram 20
HTTP Method: PUT
Request URL: /answer/:aId
Request Data:
Format: JSON
Structure: { "content": (String), "isBest": (boolean), "views": (Integer), "likes":
(Integer)}
Response: Resource not found (404) if answer does not exist, OK (200) if answer
updated successfully, or bad request (400) if fail to update the answer.
Comments: Send this request to update an existing answer.
Diagram:
Figure 47 API diagram 21
HTTP Method: DELETE
Request URL: /answers/:aId
Request Data: Null
Response: Resource not found (404) if answer does not exist, OK (200) if answer deleted
successfully, or bad request (400) if fail to delete the answer.
Comments: Send this request to delete an existing answer.
Diagram:

67. 56
Figure 48 API diagram 22
HTTP Method: POST
Request URL: /categories
Request Data:
Format: JSON
Structure: {"cName": (String), "fNumber": (Integer)}
Response: OK(200) if category created successfully, or bad request if failed to create the
category.
Comments: Send this request to create a category.
Diagram:
Figure 49 API diagram 23
HTTP Method: GET
Request URL: /categories/:cId
Request Data: Null
Response:
Resource not found (404) if category does not exist
otherwise
Format: JSON
Structure: {“cId”: (Long), “cName”: (String), “fNuber”: (Integer), “createdDate”:
(String), “createdTime”: (String)}

68. 57
Comments: Send this request to get the information of a particular category
Diagram:
Figure 50 API diagram 24
HTTP Method: PUT
Request URL: /categories/:cId
Request Data:
Format: JSON
Structure: {“cName”: (String), “fNuber”: (Integer)}
Response: Resource not found (404) if category does not exist; OK (200) if update
category successfully or bad request (400) if fail to update the category.
Comments: Send this request to update an existing category
Diagram:
Figure 51 API diagram 25
HTTP Method: DELETE
Request URL: /categories/:cId
Request Data: Null
Response: Resource not found (404) if category does not exist; OK (200) if delete
category successfully or bad request (400) if fail to delete the category.
Comments: Send this request to delete existing category.
Diagram:

69. 58
Figure 52 API diagram 26
HTTP Method: GET
Request URL: /notifications/:nId
Request Data: Null
Response:
Resource not found (404) if notification does not exist
otherwise
Format: JSON
Structure: {“nId”: (Long), “uId”: (Long), “qId”: (Long), “qTitle”: (String),
“createdTime”: (String), “createdDate”: (String), “Status”: (String), “type”: (String),
“comment”: (String)}
Comments: Send this request to get the information of a notification.
Diagram:
Figure 53 API diagram 27
HTTP Method: GET
Request URL: /usernotification/:uId
Request Data: Null
Response:
Resource not found (404) if user does not exist
otherwise

70. 59
Format: JSON array
Structure: Array of {“nId”: (Long), “uId”: (Long), “qId”: (Long), “qTitle”:
(String), “createdTime”: (String), “createdDate”: (String), “Status”: (String), “type”:
(String), “comment”: (String)}
Comments: Send this request to get all notification of a particular user
Diagram:
Figure 54 API diagram 28
HTTP Method: PUT
Request URL: /notifications/:nId
Request Data:
Format: JSON
Structure: {“Status”: (String), “type”: (String), “comment”: (String)}
Response: Resource not found (404) if notification does does not exist, OK(200) if
notification updated successfully, or bad request(400) if fail to update the notification
Comments: Send this request to update an existing notification.
Diagram:
Figure 55 API diagram 29
HTTP Method: DELETE

71. 60
Request URL: /notifications/:nId
Request Data: Null
Response: Resource not found (404) if notification does not exist, OK (200) if
notification deleted successfully, or bad request (400) if fail to delete the notification
Comments: Send this request to delete an existing notification.
Diagram:
Figure 56 API diagram 30
HTTP Method: GET
Request URL: /userunreadnotification/:uId
Request Data: Null
Response:
Resource not found (404) if user does not exist
otherwise
Format: JSON array
Structure: Array of {“nId”: (Long), “uId”: (Long), “qId”: (Long), “qTitle”:
(String), “createdTime”: (String), “createdDate”: (String), “Status”: (String), “type”:
(String), “comment”: (String)}
Comments: Send this request to get all unread notifications of a user
Diagram:
Figure 57 API diagram 31

72. 61
4.5.2 Meteor JS server API
We also use RESTful API as the communication protocol between the client and Meteor
JS server. Below is the detail API of this server:
HTTP Method: POST
Request URL: /uploadimage
Request Data:
Format: JSON
Structure: {“image64”: (String), “uuid”: (String)}
Response: OK (200) if image uploaded successfully, or bad request (400) if fail to upload
the image.
Comments: Send this request to store images on the server. Images can either be picked
up from user’s device or device’s camera.
Diagram:
Figure 58 API diagram 32
HTTP Method: GET
Request URL: /chat/:fuId/:tuId/uuid
Request Data: Null
Response:
Resource not found (404) if user or the chat uuid does not exist
otherwise
Format: JSON
Structure: {“content”: (String)}
Comments: Send this request to retrieve the chatting content of a specific chatting.
Diagram:

73. 62
Figure 59 API diagram 33
HTTP Method: POST
Request URL: /pushnotification
Request Data:
Format: JSON
Structure: {“tId”: (Long), “title”: (String), “content”: (String), “type”: (String)}
Response: Resource not found (404) if the target user does not exist. OK (200) if push
notification sent successfully, or bad request (400) if fail to send the push notification.
Comments: Send this request to let server create a push notification for a specific user.
Diagram:
Figure 60 API diagram 34
4.6 Design problems, solutions, and patterns
One problem we faced was that on one hand we wanted to accommodate as many
clients platform as possible such Android, iOS and web, and on the other hand we don’t
have enough resource to achieve that. The solution would be using Meteor JS server, but

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at that time we already had our server ready which is a Play server written in Java.
Ideally, we should either rewrite server using Meteor JS framework, or choose other
client side framework instead of Meteor JS. The decision was that keeping the old Play
server and coming up with a new Meteor JS server when it comes to new functionalities.
The result is that we managed to run our platform using two totally different servers at
the same time. Although it did bring us some overhead and redundant in the code, it
works fine.
Another problem we faced was that ideally we could store image data in image
format such as jpeg, png and so on. In this way we could store very large images. But
considering the fact that we don’t want to spend more on storage and we are not familiar
with AWS S3 API, we came up with a solution which is store the image data in its 64bit
String format, and we put the String representations of images into Mongo DB. In this
way we don’t need large storage and we are familiar with Mongo DB, so it really brought
us the benefit of fast development. On the other hand as the length of a String cannot be
too long in Mongo DB, we are not able to store very large images. This is not a big
problem as images taken by mobile devices are not that big. We still manage to make the
image uploading functionality work properly.

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Chapter 5 System Implementation
5.1 System implementation summary
1) Play server is established and all required functionalities APIs are
completed.
• User Authentication Model is completed.
• Question Model is completed
• Answer Model is completed
• Question routing Model is completed
• Categories Model is completed
• Notification Model is completed
2) Meteor server is established.
• Images uploading Model is completed
• Take pictures from camera Model is completed
• Message Chatting Model is completed
• Video Chatting Model 80% completed
3) Summary
Basic requirements are all completed. Optional requirements are almost finished
with high percentage. Server side work is all done. Recent work focuses on client side UI
improvements.
5.2 System implementation issues and resolutions

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Issue Resolution
Since all members are new to Mobile
Apps developments, it’s not easy to
develop Mobile App within short time.
We use Cordova framework plus
MeteorJS, which supports html, css and
JavaScript to develop native app.
Since play server uses http API to post
and get data, it’s hard to provide reactive
chatting environments unless refresh
current page.
In order to solve this issue, we use Meteor
Server, which uses DDP portal to provide
reactive chatting environment.
Table 20 System implementation issues and resolutions
5.3 Used technologies and tools
Server Technologies Description
AWS EC2
Both play server and meteor are implemented on
Amazon EC2 cloud servers. AWS EC2 provides on
demand host configuration.
MySQL MySQL is used for play server database, since it’s a
open source storage and provides lots of great features.
Play Framework Play Framework makes it easy to build web
applications with Java
MeteorJS Provides full stack development for both server and
client with JavaScript
MongoDB Database associated with meteor server.
Table 21 Used server technologies

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Client Technologies Description
HTML5/CSS Thanks to MeteorJS and Cordova, Html5 and CSS can
be used to development mobile app user interface
jQuery JavaScript library to provide client-side activities.
Cordova JavaScript app development platform which build
JavaScript app into mobile native app
Ionic
Beautiful and well developed open source front-end
SDK for developing mobile apps with web
technologies
PhoneGap push notification Implement push notification for Android app, iOS app,
and web app using JavaScript.
Table 22 Used client technologies
Development Tools Description
Eclipse IDE for java development
IntelliJ IDE for both java and JavaScript development
Sublime Popular text editor
Android SKD Studio Android emulator and package management
Table 23 Development tools

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Chapter 6 System Testing and Experiment
This section is going to show test of our project and make sure the system is
functioning 100% correct and no error as well as the UI is friendly enough for any type of
users; system running-time performance.
6.1 Testing and experiment scope
Our testing is mainly based on black box and white box testing. It is carried out at
both component level and system level.
Testing process Scope
Unit testing Individual or group of related units will be tested in this
test. This test will be performed in each sprint. It is white
box testing.
Component testing Functions of each component will be tested.
GUI testing All user interfaces will be tested manually, including text
and buttons, etc.
Integration Testing We will test the combined output of a group of components
in this part. Thus, we will do this test with several sprints.
It is one of black box testing.
System Testing This test is going to test the system in different
environments such as OS or devices. In this test, we will
need to make sure our Android app is working on different
models of devices. It is one of black box testing.
Compatibility testing The application working on web, Android and iOS
simulators and devices is tested.
Performance Testing Speed and its efficiency are important to our product so
this test is required so there is not unnecessary wait for
users. It is one of black box testing.
Table 24 Testing scope

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6.2 Testing and experimental approaches
Testing methods and criteria are described in this section.
Testing process Testing method Testing criteria
GUI testing Black box test, manual All objects are clicked to test. All
navigation windows are tested.
Component testing Black box test, manual All components are tested.
RESTful APIs Postman All RESTful APIs are tested.
Integration testing Bottom-up, top-down
test
Component is tested one by one until
all of them work together.
Compatibility GUI test Front-end GUI works well on web,
Android and iOS system.
Performance Load test, usability test,
response test
The system responses in a reasonable
time.
Table 25 Testing approaches
6.3 Testing and experiment
Our product have been tested and verified all features and validate they are all in
function. We have set up a testing environment and tested our system with some tools.
6.3.1 Testing preparation
In this section, we will list all software and hardware requirements for our testing
cases.
Software Requirements:
● Testing target environment:
- Chrome Internet browser
- iOS devices with Apple developer account
- Android devices

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● JMeter
Hardware Requirements:
● Laptops (Windows and Mac)
6.3.2 Testing summary
Testing results are the following:
Play server API test
Test
Case
ID
Version Test Case Description Pass/
Fail
Tester Test Date
API-1 1.0 HTTP Method: GET Pass Feiyu Yin 10/30/2015
API-2 1.0 HTTP Method: POST (Signin) Pass Feiyu Yin 10/30/2015
API-3 1.0 HTTP Method: POST (Signup) Pass Feiyu Yin 10/30/2015
API-4 1.0 HTTP Method: GET (Heartbeat) Pass Feiyu Yin 10/30/2015
API-5 1.0 HTTP Method: GET (Logoff) Pass Feiyu Yin 10/30/2015
API-6 1.0 HTTP Method: GET (Isonline) Pass Feiyu Yin 10/30/2015
API-7 1.0 HTTP Method: GET (Chat) Pass Feiyu Yin 10/30/2015
API-8 1.0 HTTP Method: GET (Users) Pass Feiyu Yin 10/30/2015
API-9 1.0 HTTP Method: GET
(userbyumid)
Pass Feiyu Yin 10/30/2015
API-10 1.0 HTTP Method: PUT (Users) Pass Feiyu Yin 10/30/2015
API-11 1.0 HTTP Method: DELETE (Users) Pass Feiyu Yin 10/30/2015
API-12 1.0 HTTP Method: POST
(Questions)
Pass Junchen
Zhu
10/30/2015
API-13 1.0 HTTP Method: GET (Questions) Pass Junchen
Zhu
10/30/2015
API-14 1.0 HTTP Method: GET
(Userquestion)
Pass Junchen
Zhu
10/30/2015

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API-15 1.0 HTTP Method: GET
(Answerquestion)
Pass Junchen
Zhu
10/30/2015
API-16 1.0 HTTP Method: PUT (Questions) Pass Junchen
Zhu
10/30/2015
API-17 1.0 HTTP Method: DELETE
(Questions)
Pass Junchen
Zhu
10/30/2015
API-18 1.0 HTTP Method: POST (Answer) Pass Junchen
Zhu
10/30/2015
API-19 1.0 HTTP Method: GET (Answers) Pass Junchen
Zhu
10/30/2015
API-20 1.0 HTTP Method: GET
(Questionsanswer)
Pass Junchen
Zhu
10/30/2015
API-21 1.0 HTTP Method: PUT (Answer) Pass Junchen
Zhu
10/30/2015
API-22 1.0 HTTP Method: DELETE
(Answers)
Pass Bingyu Li 10/30/2015
API-23 1.0 HTTP Method: POST
(Categories)
Pass Bingyu Li 10/30/2015
API-24 1.0 HTTP Method: GET
(Categories)
Pass Bingyu Li 10/30/2015
API-25 1.0 HTTP Method: PUT
(Categories)
Pass Bingyu Li 10/30/2015
API-26 1.0 HTTP Method: DELETE
(Categories)
Pass Bingyu Li 10/30/2015
API-27 1.0 HTTP Method: GET
(Notifications)
Pass Bingyu Li 10/30/2015
API-28 1.0 HTTP Method: GET
(Usernotification)
Pass Bingyu Li 10/30/2015
API-29 1.0 HTTP Method: PUT
(Notification)
Pass Bingyu Li 10/30/2015
API-30 1.0 HTTP Method: DELETE
(Notification)
Pass Bingyu Li 10/30/2015

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API-31 1.0 HTTP Method: GET
(Userunreadnotification)
Pass Bingyu Li 10/30/2015
User Interface Test
Test
Case
ID
Version Test Case Description Pass/
Fail
Tester Test Date
UI-1 1.0 Login with username and
password
Pass Daniel 11/1/2015
UI-2 1.0 Main page button testing Pass Daniel 11/1/2015
UI-3 1.0 Question post: Post Pass Daniel 11/1/2015
UI-4 1.0 Question post: Cancel Pass Daniel 11/1/2015
UI-5 1.0 Question post Tagging Pass Daniel 11/1/2015
UI-6 1.0 Question post: Assign credit Pass Daniel 11/1/2015
UI-7 1.0 Question post: Categories Pass Daniel 11/1/2015
UI-8 1.0 Answer post: Post Pass Daniel 11/1/2015
UI-9 1.0 Answer post: Cancel Pass Daniel 11/1/2015
UI-10 1.0 Answer post: showing correct
question title
Pass Daniel 11/1/2015
UI-11 1.0 Answer post: Hidden answers Pass Daniel 11/1/2015
UI-12 1.0 Question: Go to detail Pass Feiyu Yin 11/1/2015
UI-13 1.0 Question: Next Page Pass Feiyu Yin 11/1/2015
UI-14 1.0 Question: Back Pass Feiyu Yin 11/1/2015
UI-15 1.0 Notifications Pass Feiyu Yin 11/1/2015
UI-16 1.0 Answers showing Pass Feiyu Yin 11/1/2015
UI-17 1.0 Pictures upload Pass Feiyu Yin 11/1/2015
UI-18 1.0 Picture showing Pass Feiyu Yin 11/1/2015

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Data
Designed Test Case : 49
Executed Test Case: 49
Test Coverage: 100%
No Bugs report.

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Chapter 7 Conclusion and Future Work
7.1 Project summary
Real Time Question and Answer Platform is basically a new revolutionary
product, which combine with traditional crowdsourcing Q&A problem solving
technology and integrated with high efficient routing and multi-OS interface system. It
can break the rule that users have to wait for some unwanted time. Also, it can reduce our
expert to search for their expertise question to answer since each subscribed categories
questions will automatically feed notifications to our expert devices or computers. On the
other hand, users can share their comments or knowledge more than just text. Users can
have instance videoconference and pictures sharing. Traditional Q&A system can allow
users just communicate with text, which is hard to share some complicated explanation.
At the beginning of this project, we have decided to work on Android application
first then create the iOS version. However, we have done some more research in May to
check the user's ratio for iOS or Android and how they affect users each other. We found
that if we deploy our application to iOS, we cannot only increase the users in iOS and
also in Android as well. So, we were looking for a better way to develop both
applications simultaneously. Luckily, we found that Meteor is a pretty great framework to
use for development. Also we have learned that, in order to get the best result for our
application, we need to cover most users platforms (Android and iOS). These two
platforms are correlated. For example, if an iOS user has some Android friends, then he

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can invite them to join our system. If either side application is not exist, we may lose both
sides users.
7.2 Future work
In the future, continuous development is needed for providing better services for
our users. The first work we need to do is collecting more comments and feedback from
our users. We need to collect more information such as what categories our users would
spend more time and how they find for the user interface. After collecting these “big
data”, we would adjust our system to be more user-friendly to our users.
Questions and Answers have no limit. We will develop more search function such
that users can search some solutions from our system to outside resources besides our
data bank. We can enhance our system to analyze specific words with categories to do
Google search. When we type in Google search, Google may reply us thousands of
results. Our goal is to reduce redundancy and show most important results to our users.
However, this feature would require more data such as how users would choose the best
answers, so this would take some time to develop.
Technology is developing everyday, so we would keep in touch with the new
technology such as new frameworks or new features. We would deploy new features
when we find these features such as “whiteboard” could help our users to use our system
and give them better service.

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Also, we will keep updating our system interface so our users would feel
refreshing when they use our system everyday. While we will update the interface, this
could also enhance the system response time as well.

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References
[1] LEX parser, 2014. Retrieved from http://nlp.stanford.edu/software/lex-parser.shtml
[2] Shift-reduce constituency parser. 2014. Retrieved from
http://nlp.stanford.edu/software/lex-parser.shtml
[3] Richard Socher, John Bauer, Christopher D. Manning and Andrew Y. Ng. 2013.
Parsing with compositional vector grammars. In Proceedings of the ACL Conference.
[4] Danqi Chen and Christopher D Manning. 2014. A fast and accurate dependency
parser using neural networks. Proceedings of the 2014 Conference on Empirical
Methods in Natural Language Processing (EMNLP), Doha, Qatar. 740-750.
[5] Daren C. Brabham. 2008. Crowdsourcing as a model for problem solving an
introduction and cases. University of Utah, USA. doi:10.1177/1354856507084420
[6] Symposium on mining answers from texts and knowledge bases. 2002. The 2002
AAAI Spring Symposium Series, Stanford University.
[7] E. Hovy, U. Hermjakob and C. Lin. 2002. The use of external knowledge in factoid
QA. In Proceedings of the Tenth Text REtrieval Conference (TREC 2001), 644-652.
Retrieved from http://trec.nist.gov/pubs/trec10/papers/TREC10-webclopedia.pdf
[8] Simon Ostermann, Alexandru Iosup, Nezih Yigitbas, Radu Prodan, Thomas
Fahringe, and Dick Eperna. 2010. A Performance Analysis of EC2 Cloud
Computing Services for Scientific Computing. Cloud computing, Springer, 115-131.
Retrieved from http://link.springer.com/chapter/10.1007/978-3-642-12636-
9_9#page-1
[9] S. Abney, M. Collins and A. Singhal. 2000. Answer extraction. In Proceedings of
the 6th Applied Natural Language Processing Conference (ANLP 2000), 296-301.
[10] S. Harabagiu, D. Moldovan, M. Pasca, R. Mihalcea, M. Surdeanu, R. Bunescu, R.
Girju, V. Rus and P. Morarescu. 2001. FALCON: Boosting knowledge for question
answering. In Proceedings of the Ninth Text REtrieval Conference (TREC-9), 479-
488.
[11] J. Chen, A. R. Diekema, M. D. Taffet, N. McCracken, N. E. Ozgencil, O.
Yilmazel, E. D. Liddy. 2002. Question answering: CNLP at the TREC-10 question
answering track. In Proceedings of the Tenth Text REtrieval Conference (TREC
2001).

88. 77
[12] C. Kwok, O. Etzioni and D. Weld. 2001. Scaling question answering to the Web.
In Proceedings of the 10th World Wide Web Conference (WWW’10), 150-161.
[13] O. Etzioni. Moving up the information food chain: softbots as information
carnivores. 1996. In Proceedings of the Thirteenth National Conference on Artificial
Intelligence. Revised version reprinted in AI Magazine special issue, summer ’97.