This presentation introduces some concepts about the Java Collection framework. These slides introduce the following concepts:
- Collections and iterators
- Linked list and array list
- Hash set and tree set
- Maps
- The collection framework
The presentation is took from the Java course I run in the bachelor-level informatics curriculum at the University of Padova.
Collections Framework is a unified architecture for managing collections, Main Parts of Collections Framework
1. Interfaces :- Core interfaces defining common functionality exhibited by collections
2. Implementations :- Concrete classes of the core interfaces providing data structures
3. Operations :- Methods that perform various operations on collections
Collections Framework is a unified architecture for managing collections, Main Parts of Collections Framework
1. Interfaces :- Core interfaces defining common functionality exhibited by collections
2. Implementations :- Concrete classes of the core interfaces providing data structures
3. Operations :- Methods that perform various operations on collections
In this core java training session, you will learn Collections – Lists, Sets. Topics covered in this session are:
• List – ArrayList, LinkedList
• Set – HashSet, LinkedHashSet, TreeSet
For more information about this course visit on this link: https://www.mindsmapped.com/courses/software-development/learn-java-fundamentals-hands-on-training-on-core-java-concepts/
Java Collections | Collections Framework in Java | Java Tutorial For Beginner...Edureka!
**** Java Certification Training: https://www.edureka.co/java-j2ee-soa-training ****
This Edureka tutorial on “Java Collections” will talk about the complete hierarchy of Collections Frameworks in Java. It will walk you through the various fundamentals of collections like Lists, Queue, Sets, Interfaces etc. Through this tutorial you will learn the following topics:
Java Collection Framework
Collection Framework Hierarchy
Interfaces
List
Queue
Set
Check out our Java Tutorial blog series: https://goo.gl/osrGrS
Check out our complete Youtube playlist here: https://goo.gl/gMFLx3
To learn important concept of Collection and its handling plus its advantages and different class & child class of Collection and their implementations. Important interview questions of the collection.
This presentation talks about the five SOLID principles of Object Oriented Design described by Rober C. Martin in his best-seller book "Agile Principles, Patterns, and Practices in C#". The five principle described are:
- Single Responsibility Principle
- Open-Close Principle
- Liskov Substitution Principle
- Interface Segregation Principle
- Dependency Inversion Principle
The presentation is took from the Software Engineering course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation introduces the concept of synchronization beatween threads, as implemented in the Java platform. It is the first part of a series of slides dedicated to thread synchronization. This slides introduces the following concepts:
- Thread safety
- Types of race conditions
- Locking (reentrant locks, intrinsic locks, synchronized blocks)
- Locking pitfalls
The presentation is took from the Java course I run in the bachelor-level informatics curriculum at the University of Padova.
In this core java training session, you will learn Collections – Lists, Sets. Topics covered in this session are:
• List – ArrayList, LinkedList
• Set – HashSet, LinkedHashSet, TreeSet
For more information about this course visit on this link: https://www.mindsmapped.com/courses/software-development/learn-java-fundamentals-hands-on-training-on-core-java-concepts/
Java Collections | Collections Framework in Java | Java Tutorial For Beginner...Edureka!
**** Java Certification Training: https://www.edureka.co/java-j2ee-soa-training ****
This Edureka tutorial on “Java Collections” will talk about the complete hierarchy of Collections Frameworks in Java. It will walk you through the various fundamentals of collections like Lists, Queue, Sets, Interfaces etc. Through this tutorial you will learn the following topics:
Java Collection Framework
Collection Framework Hierarchy
Interfaces
List
Queue
Set
Check out our Java Tutorial blog series: https://goo.gl/osrGrS
Check out our complete Youtube playlist here: https://goo.gl/gMFLx3
To learn important concept of Collection and its handling plus its advantages and different class & child class of Collection and their implementations. Important interview questions of the collection.
This presentation talks about the five SOLID principles of Object Oriented Design described by Rober C. Martin in his best-seller book "Agile Principles, Patterns, and Practices in C#". The five principle described are:
- Single Responsibility Principle
- Open-Close Principle
- Liskov Substitution Principle
- Interface Segregation Principle
- Dependency Inversion Principle
The presentation is took from the Software Engineering course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation introduces the concept of synchronization beatween threads, as implemented in the Java platform. It is the first part of a series of slides dedicated to thread synchronization. This slides introduces the following concepts:
- Thread safety
- Types of race conditions
- Locking (reentrant locks, intrinsic locks, synchronized blocks)
- Locking pitfalls
The presentation is took from the Java course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation introduces the concept of synchronization beatween threads, as implemented in the Java platform. It is the second part of a series of slides dedicated to thread synchronization. This slides introduces the following concepts:
- Conditional locking
- Volatile variables
- Thread confinement
- Immutability
The presentation is took from the Java course I run in the bachelor-level informatics curriculum at the University of Padova.
Java Exception Handling, Assertions and LoggingRiccardo Cardin
This presentation introduces the java exception handling mechanisms. In detail, the main focus of the slides is to show how the language implements its exception handling polices, such as:
- Checked and uncheked exception
- Try / catch blocks
- Assertions
- Logging
The presentation is took from the Java course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation introduces some advanced concepts of threads, as implemented in the Java platform. It is part of a series of slides dedicated to threads. This slides introduces the following concepts:
- Callable
- Futures
- Executors and executor services
- Deadlocks (brief introduction)
The presentation is took from the Java course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation introduces the main features of Swing, an UI development library for the Java ecosystem. The main focus of the slides is to show the basic features of Swing, such as:
- Main components (JFrame, JPanel, ...)
- Layout management (FlowLayout, BorderLayout, GridLayout, ...)
- Event handling
The presentation is took from the Java course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation introduces the main features of Scala, an object oriented and functional programming language. The main focus of the slides is to show how the language implements natively some of the patterns and best practices that are no present in other programming languages, such as Java, C++ and so on.
In detail, the presentation spans these concepts:
- Language's main syntax
- Classes, abstract classes, objects and traits (mixin)
- The Option class
- An introduction to generics
- Implicit classes
- Functions
- Recursion (simple and tail)
- Currying
- Call by value / name
The presentation is took from the Software Engineering course I run in the bachelor-level informatics curriculum at the University of Padova.
Design pattern architetturali Model View Controller, MVP e MVVMRiccardo Cardin
This presentation talks about model view controller, model view presenter and model view viewmodel patterns. These are architectural design patterns for implementing user interfaces. They divide a given software application into three interconnected parts, so as to separate internal representations of information from the ways that information is presented to or accepted from the user. Also, they promote separation of concerns. As examples, some frameworks are reported, such as:
- Spring MVC
- BackboneJS
- AngularJS
The presentation is took from the Software Engineering course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation talks about structural design patterns. In software engineering, structural design patterns are design patterns that ease the design by identifying a simple way to realize relationships between entities. In particular in the slides are described the following patterns:
- Decorator
- Proxy
- Facade
- Adapter
Design patterns are presented using examples in Java, Scala and Javascript.
The presentation is took from the Software Engineering course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation introduces basic concepts about the Java I/O framework based on input and output streams. These slides introduce the following concepts:
- Obtaining streams
- Reading / writing bytes
- Character encodings
- Text input / output
- Random access files
- Processing files
- URLs
- Serialization
The presentation is took from the Java course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation talks about some commonly used software architecture patterns. The main features of the following architectural patterns are described:
- Layered architecture
- Event-driven architecture (both mediator and broker topology)
- Microservices architecture (API-REST based, REST based, Centralized message topology)
Each pattern is analyzed in terms of:
- Overall agility
- Ease of deployment
- Testability
- Performance
- Scalability
- Ease of develpment.
The slide refers to the online book "Software Architecture Patterns", Mark Richards, 2015, O’Reilly.
The presentation is took from the Software Engineering course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation is based on Joakim\’s experiences from moving from Java to Scala http://www.scala-lang.org/node/960#Joak We will explore how to move from Java to Scala and why. We\’ll look at things that you will run into sooner rather than later such as Scala\’s collection APIs, Options and higher order functions and special syntax. You will leave this presentation with good foundation to use Scala in practice; perhaps even in your current Java project and ideally with an appetite to learn more.
This presentation introduces the concept of design pattern in object oriented programming and design. The slides contain information about what a design pattern is, why should we use design pattern and how design patterns could be grouped togheter. The ideas presented in the slides are taken directly from GoF's book "Design Patterns".
The presentation is took from the Software Engineering course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation introduces basic concepts about the Java Remote Method Invocation, a.k.a. RMI. These slides introduce the following concepts:
- Remote interfaces
- Dynamic code loading
- Serialization
- Security manager
- Exporting remote objects
- Compiling and running RMI programs
- Distributed garbage collection
The presentation is took from the Java course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation introduces basic concepts about the Java socket abstraction. These slides introduce the following concepts:
- What is a socket
- How to implement a client program
- How to implement a server program
The presentation is took from the Java course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation talks about dependecy injection, an architectural design pattern that aims to help developer to resolve dependencies between objects. Starting by describing general problem of dependecy resolution, the presentation continues presenting Inversion of Control (IoC) pattern, constructor injection and setting injection. As examples, some frameworks and libraries are reported, such as:
- Google Guice
- Spring framework
- AngularJS
The presentation is took from the Software Engineering course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation introduces some advanced concepts of generics in Java. These slides introduce the following concepts:
- Generic classes and methods
- Type variable bounds
- Type erasure process
- Generics and inheritance
- Wildcard types
The presentation is took from the Java course I run in the bachelor-level informatics curriculum at the University of Padova.
Errori comuni nei documenti di Analisi dei RequisitiRiccardo Cardin
This presentation talks about common errors that I found in my career in documents of specification of requirements. In the presentation are described common errors on use cases, use cases' diagrams and on requirements' specification.
The presentation is took from the Software Engineering course I run in the bachelor-level informatics curriculum at the University of Padova.
In this session you will learn:
List – ArrayList, LinkedList
Set – HashSet, LinkedHashSet, TreeSet
For more information: https://www.mindsmapped.com/courses/software-development/become-a-java-developer-hands-on-training/
Collection Framework in Java | Generics | Input-Output in Java | Serializatio...Sagar Verma
Collection Framework in Java,Generics,Input-Output in Java,Serialization,Inner Classes
Collection Framework in Java
The Collections Framework - Set Interface- List Interface - Map Interface - Queue Interface -Sorting collections using utility methods
equals () and hash Code contract in Java collections
Overriding equals and hash Code methods in Java
Generics
Generics for Collections, class and methods
Input-Output in Java
What is a stream? ,Bytes vs. Characters, Java IO API ,Reading a file; writing to a file using various APIs
Reading User input from console , PrintWriter Class
Serialization
Object Serialization , Serializable Interface , De-Serializable
Inner Classes
Inner Classes ,Member Classes, Local Classes, Anonymous Classes, Static Nested Classes
This presentation introduces the Java concept of thread. It is the first part of a series of slides dedicated to concurrent programming. This slides introduces some basics concepts, such as:
- Differences between processes and threads
- Thread's basics
- Thread's states
- Introduction to UML sequence diagrams
The presentation is took from the Java course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation talks about behavioural design patterns. In software engineering, behavioral design patterns are design patterns that identify common communication patterns between objects and realize these patterns. By doing so, these patterns increase flexibility in carrying out this communication. In particular in the slides are described the following patterns:
- Command
- Iterator
- Observer
- Strategy
- Template Method
Design patterns are presented using examples in Java, Scala and Javascript.
The presentation is took from the Software Engineering course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation talks about creational design patterns. In software engineering, creational design patterns are design patterns that deal with object creation mechanisms, trying to create objects in a manner suitable to the situation. In particular in the slides are described the following patterns:
- Singleton
- Builder
- Abstract Factory
Design patterns are presented using examples in Java, Scala and Javascript.
The presentation is took from the Software Engineering course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation talks about the main features of UML class diagrams. The slides contain information about how to use sequence diagrams to represent components' interactions in a software system. UML 2.x featuers are also described, like frames.
The presentation is took from the Software Engineering course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation talks about the main features of UML activity diagrams. The slides contain information about which are the main components of activity diagrams, how to use them to represent business processes and software algorithms.
The presentation is took from the Software Engineering course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation talks about the main features of UML class diagrams. The slides contain information about how to represent a class, what is a classe feature, what are possible association types, class dependency, hineritance and subtyping.
The presentation is took from the Software Engineering course I run in the bachelor-level informatics curriculum at the University of Padova.
This presentation talks about the main features of UML use cases and use cases diagrams. The slides contain information about what is a scenario, an actor, an use case and interactions between them.
The presentation is took from the Software Engineering course I run in the bachelor-level informatics curriculum at the University of Padova.
A brief introduction to UML: the history, what are the problems that UML tries to resolve and how we should use it during software design and development.
The presentation is took from the Software Engineering course I run in the bachelor-level informatics curriculum at the University of Padova.
A very introductive presentation about how Model-View-Controller pattern (MVC) and Dependence Injection (DI) are implemented in some popular frameworks, such as Spring and Angular JS.
The presentation is took from the Software Engineering course I run in the bachelor-level informatics curriculum at the University of Padova.
A very introductive presentation about reactive programming principles. Starting from synchronous standard programming, I try to present the needs that driven to reactive programming. Callbacks, Future, Promises, Observables and Actor model are the main issues. I also make an introduction to the Reactive Manifesto.
The presentation is took from the Software Engineering course I run in the bachelor-level informatics curriculum at the University of Padova.
Into the Box Keynote Day 2: Unveiling amazing updates and announcements for modern CFML developers! Get ready for exciting releases and updates on Ortus tools and products. Stay tuned for cutting-edge innovations designed to boost your productivity.
TROUBLESHOOTING 9 TYPES OF OUTOFMEMORYERRORTier1 app
Even though at surface level ‘java.lang.OutOfMemoryError’ appears as one single error; underlyingly there are 9 types of OutOfMemoryError. Each type of OutOfMemoryError has different causes, diagnosis approaches and solutions. This session equips you with the knowledge, tools, and techniques needed to troubleshoot and conquer OutOfMemoryError in all its forms, ensuring smoother, more efficient Java applications.
Why React Native as a Strategic Advantage for Startup Innovation.pdfayushiqss
Do you know that React Native is being increasingly adopted by startups as well as big companies in the mobile app development industry? Big names like Facebook, Instagram, and Pinterest have already integrated this robust open-source framework.
In fact, according to a report by Statista, the number of React Native developers has been steadily increasing over the years, reaching an estimated 1.9 million by the end of 2024. This means that the demand for this framework in the job market has been growing making it a valuable skill.
But what makes React Native so popular for mobile application development? It offers excellent cross-platform capabilities among other benefits. This way, with React Native, developers can write code once and run it on both iOS and Android devices thus saving time and resources leading to shorter development cycles hence faster time-to-market for your app.
Let’s take the example of a startup, which wanted to release their app on both iOS and Android at once. Through the use of React Native they managed to create an app and bring it into the market within a very short period. This helped them gain an advantage over their competitors because they had access to a large user base who were able to generate revenue quickly for them.
Developing Distributed High-performance Computing Capabilities of an Open Sci...Globus
COVID-19 had an unprecedented impact on scientific collaboration. The pandemic and its broad response from the scientific community has forged new relationships among public health practitioners, mathematical modelers, and scientific computing specialists, while revealing critical gaps in exploiting advanced computing systems to support urgent decision making. Informed by our team’s work in applying high-performance computing in support of public health decision makers during the COVID-19 pandemic, we present how Globus technologies are enabling the development of an open science platform for robust epidemic analysis, with the goal of collaborative, secure, distributed, on-demand, and fast time-to-solution analyses to support public health.
Understanding Globus Data Transfers with NetSageGlobus
NetSage is an open privacy-aware network measurement, analysis, and visualization service designed to help end-users visualize and reason about large data transfers. NetSage traditionally has used a combination of passive measurements, including SNMP and flow data, as well as active measurements, mainly perfSONAR, to provide longitudinal network performance data visualization. It has been deployed by dozens of networks world wide, and is supported domestically by the Engagement and Performance Operations Center (EPOC), NSF #2328479. We have recently expanded the NetSage data sources to include logs for Globus data transfers, following the same privacy-preserving approach as for Flow data. Using the logs for the Texas Advanced Computing Center (TACC) as an example, this talk will walk through several different example use cases that NetSage can answer, including: Who is using Globus to share data with my institution, and what kind of performance are they able to achieve? How many transfers has Globus supported for us? Which sites are we sharing the most data with, and how is that changing over time? How is my site using Globus to move data internally, and what kind of performance do we see for those transfers? What percentage of data transfers at my institution used Globus, and how did the overall data transfer performance compare to the Globus users?
Prosigns: Transforming Business with Tailored Technology SolutionsProsigns
Unlocking Business Potential: Tailored Technology Solutions by Prosigns
Discover how Prosigns, a leading technology solutions provider, partners with businesses to drive innovation and success. Our presentation showcases our comprehensive range of services, including custom software development, web and mobile app development, AI & ML solutions, blockchain integration, DevOps services, and Microsoft Dynamics 365 support.
Custom Software Development: Prosigns specializes in creating bespoke software solutions that cater to your unique business needs. Our team of experts works closely with you to understand your requirements and deliver tailor-made software that enhances efficiency and drives growth.
Web and Mobile App Development: From responsive websites to intuitive mobile applications, Prosigns develops cutting-edge solutions that engage users and deliver seamless experiences across devices.
AI & ML Solutions: Harnessing the power of Artificial Intelligence and Machine Learning, Prosigns provides smart solutions that automate processes, provide valuable insights, and drive informed decision-making.
Blockchain Integration: Prosigns offers comprehensive blockchain solutions, including development, integration, and consulting services, enabling businesses to leverage blockchain technology for enhanced security, transparency, and efficiency.
DevOps Services: Prosigns' DevOps services streamline development and operations processes, ensuring faster and more reliable software delivery through automation and continuous integration.
Microsoft Dynamics 365 Support: Prosigns provides comprehensive support and maintenance services for Microsoft Dynamics 365, ensuring your system is always up-to-date, secure, and running smoothly.
Learn how our collaborative approach and dedication to excellence help businesses achieve their goals and stay ahead in today's digital landscape. From concept to deployment, Prosigns is your trusted partner for transforming ideas into reality and unlocking the full potential of your business.
Join us on a journey of innovation and growth. Let's partner for success with Prosigns.
Listen to the keynote address and hear about the latest developments from Rachana Ananthakrishnan and Ian Foster who review the updates to the Globus Platform and Service, and the relevance of Globus to the scientific community as an automation platform to accelerate scientific discovery.
Modern design is crucial in today's digital environment, and this is especially true for SharePoint intranets. The design of these digital hubs is critical to user engagement and productivity enhancement. They are the cornerstone of internal collaboration and interaction within enterprises.
Your Digital Assistant.
Making complex approach simple. Straightforward process saves time. No more waiting to connect with people that matter to you. Safety first is not a cliché - Securely protect information in cloud storage to prevent any third party from accessing data.
Would you rather make your visitors feel burdened by making them wait? Or choose VizMan for a stress-free experience? VizMan is an automated visitor management system that works for any industries not limited to factories, societies, government institutes, and warehouses. A new age contactless way of logging information of visitors, employees, packages, and vehicles. VizMan is a digital logbook so it deters unnecessary use of paper or space since there is no requirement of bundles of registers that is left to collect dust in a corner of a room. Visitor’s essential details, helps in scheduling meetings for visitors and employees, and assists in supervising the attendance of the employees. With VizMan, visitors don’t need to wait for hours in long queues. VizMan handles visitors with the value they deserve because we know time is important to you.
Feasible Features
One Subscription, Four Modules – Admin, Employee, Receptionist, and Gatekeeper ensures confidentiality and prevents data from being manipulated
User Friendly – can be easily used on Android, iOS, and Web Interface
Multiple Accessibility – Log in through any device from any place at any time
One app for all industries – a Visitor Management System that works for any organisation.
Stress-free Sign-up
Visitor is registered and checked-in by the Receptionist
Host gets a notification, where they opt to Approve the meeting
Host notifies the Receptionist of the end of the meeting
Visitor is checked-out by the Receptionist
Host enters notes and remarks of the meeting
Customizable Components
Scheduling Meetings – Host can invite visitors for meetings and also approve, reject and reschedule meetings
Single/Bulk invites – Invitations can be sent individually to a visitor or collectively to many visitors
VIP Visitors – Additional security of data for VIP visitors to avoid misuse of information
Courier Management – Keeps a check on deliveries like commodities being delivered in and out of establishments
Alerts & Notifications – Get notified on SMS, email, and application
Parking Management – Manage availability of parking space
Individual log-in – Every user has their own log-in id
Visitor/Meeting Analytics – Evaluate notes and remarks of the meeting stored in the system
Visitor Management System is a secure and user friendly database manager that records, filters, tracks the visitors to your organization.
"Secure Your Premises with VizMan (VMS) – Get It Now"
OpenFOAM solver for Helmholtz equation, helmholtzFoam / helmholtzBubbleFoamtakuyayamamoto1800
In this slide, we show the simulation example and the way to compile this solver.
In this solver, the Helmholtz equation can be solved by helmholtzFoam. Also, the Helmholtz equation with uniformly dispersed bubbles can be simulated by helmholtzBubbleFoam.
top nidhi software solution freedownloadvrstrong314
This presentation emphasizes the importance of data security and legal compliance for Nidhi companies in India. It highlights how online Nidhi software solutions, like Vector Nidhi Software, offer advanced features tailored to these needs. Key aspects include encryption, access controls, and audit trails to ensure data security. The software complies with regulatory guidelines from the MCA and RBI and adheres to Nidhi Rules, 2014. With customizable, user-friendly interfaces and real-time features, these Nidhi software solutions enhance efficiency, support growth, and provide exceptional member services. The presentation concludes with contact information for further inquiries.
SOCRadar Research Team: Latest Activities of IntelBrokerSOCRadar
The European Union Agency for Law Enforcement Cooperation (Europol) has suffered an alleged data breach after a notorious threat actor claimed to have exfiltrated data from its systems. Infamous data leaker IntelBroker posted on the even more infamous BreachForums hacking forum, saying that Europol suffered a data breach this month.
The alleged breach affected Europol agencies CCSE, EC3, Europol Platform for Experts, Law Enforcement Forum, and SIRIUS. Infiltration of these entities can disrupt ongoing investigations and compromise sensitive intelligence shared among international law enforcement agencies.
However, this is neither the first nor the last activity of IntekBroker. We have compiled for you what happened in the last few days. To track such hacker activities on dark web sources like hacker forums, private Telegram channels, and other hidden platforms where cyber threats often originate, you can check SOCRadar’s Dark Web News.
Stay Informed on Threat Actors’ Activity on the Dark Web with SOCRadar!
Multiple Your Crypto Portfolio with the Innovative Features of Advanced Crypt...Hivelance Technology
Cryptocurrency trading bots are computer programs designed to automate buying, selling, and managing cryptocurrency transactions. These bots utilize advanced algorithms and machine learning techniques to analyze market data, identify trading opportunities, and execute trades on behalf of their users. By automating the decision-making process, crypto trading bots can react to market changes faster than human traders
Hivelance, a leading provider of cryptocurrency trading bot development services, stands out as the premier choice for crypto traders and developers. Hivelance boasts a team of seasoned cryptocurrency experts and software engineers who deeply understand the crypto market and the latest trends in automated trading, Hivelance leverages the latest technologies and tools in the industry, including advanced AI and machine learning algorithms, to create highly efficient and adaptable crypto trading bots
Globus Connect Server Deep Dive - GlobusWorld 2024Globus
We explore the Globus Connect Server (GCS) architecture and experiment with advanced configuration options and use cases. This content is targeted at system administrators who are familiar with GCS and currently operate—or are planning to operate—broader deployments at their institution.
Software Engineering, Software Consulting, Tech Lead.
Spring Boot, Spring Cloud, Spring Core, Spring JDBC, Spring Security,
Spring Transaction, Spring MVC,
Log4j, REST/SOAP WEB-SERVICES.
Check out the webinar slides to learn more about how XfilesPro transforms Salesforce document management by leveraging its world-class applications. For more details, please connect with sales@xfilespro.com
If you want to watch the on-demand webinar, please click here: https://www.xfilespro.com/webinars/salesforce-document-management-2-0-smarter-faster-better/
Enhancing Research Orchestration Capabilities at ORNL.pdfGlobus
Cross-facility research orchestration comes with ever-changing constraints regarding the availability and suitability of various compute and data resources. In short, a flexible data and processing fabric is needed to enable the dynamic redirection of data and compute tasks throughout the lifecycle of an experiment. In this talk, we illustrate how we easily leveraged Globus services to instrument the ACE research testbed at the Oak Ridge Leadership Computing Facility with flexible data and task orchestration capabilities.
2. Programmazione concorrente e distribuita
SUMMARY
Introduction
Collections and iterators
Linked list
Array list
Hash set
Tree set
Maps
Collections framework
2Riccardo Cardin
3. Programmazione concorrente e distribuita
INTRODUCTION
Data structures can make a big difference in
programming
Do you need to search quickly? Do you need to rapidly
insert and remove element? ...
The first version of Java was supplied with a very
small set of classes
Vector, Stack, Hashtable, BitSet and Enumeration
Java needed a serious data structure library
Without the complexity of C++ STL
With the benefit of «generic algorithms» of C++ STL
The collections framework satisfies those needs
3Riccardo Cardin
4. Programmazione concorrente e distribuita
INTRODUCTION
Java collection framework separates interfaces
and implementations
It defines a set of interfaces that represents abstract
data structures
Each interface is then implemented in different ways,
each with main focus on some aspects
For example, fast insertion, fast search, fixed memory
consumption, ...
Using interfaces, you can change the implementation
simply modifying a single statement
4Riccardo Cardin
// ArrayList optimizes random access, LinkedList modification stmts
List<Integer> list = new ArrayList<>();
list = new LinkedList<>()
6. Programmazione concorrente e distribuita
COLLECTIONS AND ITERATORS
The fundamental interface for collection is the
Collection interface
The add method adds an element ot the collection
Returns true if the collection was changed by the addition
Iterators are used visit elements in the collection
Implements the Iterator design pattern
6Riccardo Cardin
public interface Collection<E> {
boolean add(E element);
Iterator<E> iterator();
// ...
}
public interface Iterator<E> {
E next();
boolean hasNext();
void remove();
}
7. Programmazione concorrente e distribuita
COLLECTIONS AND ITERATORS
Using iterators we have decoupled a collection
from the traversing policies
The order in which elements are visited depends on
the the collection type
Using the next method the collection is visited one
element at time
If the end of the collection is reached an
NoSuchElementException is thrown
Use the hasNext method to check if the collection
has more elements to visit
Think of Java iterators as being between elements
The iterator jumps over the next element
7Riccardo Cardin
8. Programmazione concorrente e distribuita
COLLECTIONS AND ITERATORS
8Riccardo Cardin
Think of Java iterators as being
between elements
While moving, the iterator returns
the current element
9. Programmazione concorrente e distribuita
COLLECTIONS AND ITERATORS
Using next and hasNext it is possibile to
traverse the collection
As of Java 5, there is an elegant shortcut to looping a
collection using iterators
To use the for each loop the data structure must
implement Iterable<E> interface
9Riccardo Cardin
for (String element : c) {
// do something with element
}
Collection<String> c = /* ... */;
Iterator<String> iter = c.iterator();
while (iter.hasNext()) {
String element = iter.next();
// do something with element
}
10. Programmazione concorrente e distribuita
COLLECTIONS AND ITERATORS
Using an iterator it possibile to remove elements
from a collection
The remove method removes the element that was
returned by the last call to next
There is a strong dependency between next and remove: it
is illegal to call remove if it wasn’t preceded by a call to next
This is the only way to safely modify a collection after
the creation of an iterator
10Riccardo Cardin
for (Iterator<String> iterator = list.iterator();
iterator.hasNext();) {
// Point the iterator to the current element
String string = iterator.next();
iterator.remove();
}
12. Programmazione concorrente e distribuita
CONCRETE COLLECTIONS
All concrete collections implement Collection
or Map interfaces
We will introduce only few of them
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Collection type Description
ArrayList An indexed sequence that grows and
shrinks dynamically
LinkedList An ordered sequence that allows efficient
insertion and removal at any location
HashSet An unordered collection that rejects
duplicates
TreeSet A sorted set
HashMap A data structure that stores key/value
associations
13. Programmazione concorrente e distribuita
LINKED LIST
A LinkedList<E> is an ordered data structure
that stores each object in a link
Each link store a reference to the next link of the seq.
In Java, a linked list is always doubly linked
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Implements List<E>
interface
14. Programmazione concorrente e distribuita
LINKED LIST
Very efficient for remove and add operations
These ops are made through an Iterator
Other elements in the list have not to be repositioned after
removal of an element
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15. Programmazione concorrente e distribuita
LINKED LIST
Also di add operation is made efficiently
through an iterator of type ListIterator<E>
Use List.listIterator method to get one
New element is added before the current position of
the iterator
Be carefull of concurrent modification using iterators
Linked list are very inefficient in random access
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interface ListIterator<E> extends Iterator<E> {
void add(E element);
E previous()
boolean hasPrevious()
}
for (int i = 0; i < list.size(); i++)
// do something with list.get(i);
16. Programmazione concorrente e distribuita
LINKED LIST
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Adding a new element
changes at most two
references
17. Programmazione concorrente e distribuita
ARRAY LIST
An ArrayList<E> is an ordered data structure
that is very efficient in random access ops.
It encapsulate a dynamically reallocated array of
objects
Adding and removing operation
are not so efficient
Reallocation of elements is needed
Use ArrayList instead of Vector
More efficient due to its not
synchronized methods
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19. Programmazione concorrente e distribuita
HASH SET
A Set<E> is a data structure that doesn’t care
about element’s ordering
A set contain the same element only once
Search operation performs very efficiently
A set is a Collection
An HashSet<E> uses hash codes to distinguish
among elements
An hashCode is a number that can be derived from
object data
You must provide an hash function to your classes
The function must be compatible with the equals method
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20. Programmazione concorrente e distribuita
HASH SET
Hash codes have to be computed quickly
Hash functions have some hash collision
Using the correct hash function the number of collision
should be unlikely
Hash table are implemented as an array of linked lists
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Using an hash function, the
bucket in which inserting a new
element is equal to
hash(element) % #bucket
If the hash function produceds values
that are randomly distributed, collision
should be rare
buckets
21. Programmazione concorrente e distribuita
HASH SET
An HashSet is implemented using an hash table
The contains method is very efficient, because it has
to lookup the element only in one bucket
An iterator to hash set visit each bucket in turn
Because of scattering, they are visited in a seemingly random
order
The add method adds an element if it is not already
present
Don’t mutate an element in a set once inserted
If the hash code of an element were to change, the
element would no longer be in the correct position
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22. Programmazione concorrente e distribuita
TREE SET
A TreeSet<E> is a sorted set
While iterating over the collection, the elements are
presented in sorted order
It uses a red-black tree to store data
Insertion is slower than insertion in an hash table, but it is
still much faster than insertion in an array or linked list
...but a tree set automatically sorts the elements ;)
The type of the elements may implement
Comparable<T>
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public interface Comparable<T> {
// It returns a value that is < 0, = 0 or > 0
int compareTo(T other);
}
23. Programmazione concorrente e distribuita
TREE SET
What if elements do not implement Comparable
or if you need more than on compation alg?
Provide a Comparator during set construction
The compare method acts like the compareTo method
Function object (lambda anyone?!)
Using an HashSet or a TreeSet?
There must be a total ordering defined on elements
You have to implement also the Comparator interface
Do you neeed elements to be sorted?
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public interface Comparator<T> {
// Defines how two elements of type T have to be compared
int compare(T a, T b);
}
25. Programmazione concorrente e distribuita
MAPS
A Map<K,V> is a data structure that allows you
to search an element using a key
A map stores key/value pairs
Key must be unique: If you call the put method twice with
the same key, the second value replaces the first one.
If no info is associated with a key, get returns null
In sets to find an element you must have a copy of it
An HashMap hashes the keys
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// HashMap implements Map
Map<String, Employee> staff = new HashMap<>();
Employee harry = new Employee("Harry Hacker");
staff.put("987-98-9996", harry);
String s = "987-98-9996";
e = staff.get(s); // gets harry
26. Programmazione concorrente e distribuita
MAPS
The collection framework does not consider a
map itself as a Collection
It is possible to obtain views of the map
If you are interested in all the values of a map, loop over the
enumeration of its entries
Iterators on views cannot add elements to the map
An UnsupportedOperationException is thrown
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Set<K> keySet() // Set of keys
Collection<K> values() // Collection of values
Set<Map.Entry<K, V>> entrySet() // Set of pairs (key,value)
for (Map.Entry<String, Employee> entry : staff.entrySet()) {
String key = entry.getKey();
Employee value = entry.getValue();
// do something with key, value
}
27. Programmazione concorrente e distribuita
THE FRAMEWORK
A framework is a set of classes that form the
basis for building advanced functionality
The Collection framework defines classes to
implement collections
The main interfaces are Collection and Map
Insertion interfaces are different between the two types
To get the elements from a Collection, just iterate over it
To get a value from a Map, use the get method
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// To insert an element in a Collection
boolean add(E element)
// To store a key/value pair in a Map
V put(K key, V value)
V get(K key)
28. Programmazione concorrente e distribuita
THE FRAMEWORK
A List is an ordered collection
There is the concept of position of an element
A list provides random access methods
Lists provides a specialized iterator, ListIterator
A Set is a Collection with no duplicates
The add method can reject a value if already present
Methods equals and hashCode are used to maintain
elements inside the set
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void add(int index, E element)
E get(int index)
void remove(int index)
void add(E element)
30. Programmazione concorrente e distribuita
THE FRAMEWORK
The framework have some companion objects
The Arrays type allows to trasform arrays into List
The list returned is a view on the array: it is not possible to
change the size of the list; elements are the same
The Collections type have a bunch of utilities
The method nCopies builds an illusory immutable list
Object is stored only once
Method singleton returns an illusory set with one element
And so on...
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static <T> List<T> asList(T... a)
List<String> settings = Collections.nCopies(100, "DEFAULT");
Collections.singleton(anObject)