This document provides an overview of core Java APIs covered on the OCA exam, including Strings, StringBuilder, arrays, sorting, and searching. It discusses that Strings are immutable sequences of characters with useful methods like length(), charAt(), indexOf(), and substring(). StringBuilder is mutable and more efficient for string manipulation than concatenating Strings. Arrays are objects that hold primitives or references in indexed memory locations. The document covers creating, accessing, and searching arrays, as well as the Arrays utility class methods like sort().
OCA Java SE 8 Exam Chapter 6 Exceptionsİbrahim Kürce
A program can fail for just about any reason. Here are just a few possibilities:
The code tries to connect to a website, but the Internet connection is down.
You made a coding mistake and tried to access an invalid index in an array.
One method calls another with a value that the method doesn't support.
OCA Java SE 8 Exam Chapter 5 Class Designİbrahim Kürce
Inheritance is the process by which the new child subclass automatically includes any public or protected primitives, objects, or methods defined in the parent class.
We refer to any class that inherits from another class as a child class, or a descendent of that class.
We refer to the class that the child inherits from as the parent class, or an ancestor of the class.
OCP Java (OCPJP) 8 Exam Quick Reference CardHari kiran G
If you are preparing to appear for Oracle Certified Professional Java SE 8 Programmer (OCPJP 8) certification exam, this a reference card (sort of long cheat sheet) meant to help you. You may want to print this reference card for your easy and quick reference when you prepare for your exam.
Access our sample Java8 certification questions.
1z0-808 certification questions ready to be used.
For each 1z0-808 certification question you can find the solution, the explanation and the exam objective of 1z0-808
OCA Java SE 8 Exam Chapter 6 Exceptionsİbrahim Kürce
A program can fail for just about any reason. Here are just a few possibilities:
The code tries to connect to a website, but the Internet connection is down.
You made a coding mistake and tried to access an invalid index in an array.
One method calls another with a value that the method doesn't support.
OCA Java SE 8 Exam Chapter 5 Class Designİbrahim Kürce
Inheritance is the process by which the new child subclass automatically includes any public or protected primitives, objects, or methods defined in the parent class.
We refer to any class that inherits from another class as a child class, or a descendent of that class.
We refer to the class that the child inherits from as the parent class, or an ancestor of the class.
OCP Java (OCPJP) 8 Exam Quick Reference CardHari kiran G
If you are preparing to appear for Oracle Certified Professional Java SE 8 Programmer (OCPJP 8) certification exam, this a reference card (sort of long cheat sheet) meant to help you. You may want to print this reference card for your easy and quick reference when you prepare for your exam.
Access our sample Java8 certification questions.
1z0-808 certification questions ready to be used.
For each 1z0-808 certification question you can find the solution, the explanation and the exam objective of 1z0-808
Java Strings Tutorial | String Manipulation in Java | Java Tutorial For Begin...Edureka!
**** Java Certification Training: https://www.edureka.co/java-j2ee-soa-training ****
This Edureka tutorial on “Java Strings” will talk about one of the most important classes of Java i.e String class. It will also talk about the various methods and interfaces implemented by the String class. Through this tutorial you will learn the following topics:
Java Strings
String Pool
Creating a String
String Methods
Check out our Java Tutorial blog series: https://goo.gl/osrGrS
Check out our complete Youtube playlist here: https://goo.gl/gMFLx3
Follow us to never miss an update in the future.
Instagram: https://www.instagram.com/edureka_learning/
Facebook: https://www.facebook.com/edurekaIN/
Twitter: https://twitter.com/edurekain
LinkedIn: https://www.linkedin.com/company/edureka
A package allows a developer to group classes (and interfaces) together. These classes will all be related in some way – they might all have to do with a specific application or perform a specific set of tasks.
Java Strings Tutorial | String Manipulation in Java | Java Tutorial For Begin...Edureka!
**** Java Certification Training: https://www.edureka.co/java-j2ee-soa-training ****
This Edureka tutorial on “Java Strings” will talk about one of the most important classes of Java i.e String class. It will also talk about the various methods and interfaces implemented by the String class. Through this tutorial you will learn the following topics:
Java Strings
String Pool
Creating a String
String Methods
Check out our Java Tutorial blog series: https://goo.gl/osrGrS
Check out our complete Youtube playlist here: https://goo.gl/gMFLx3
Follow us to never miss an update in the future.
Instagram: https://www.instagram.com/edureka_learning/
Facebook: https://www.facebook.com/edurekaIN/
Twitter: https://twitter.com/edurekain
LinkedIn: https://www.linkedin.com/company/edureka
A package allows a developer to group classes (and interfaces) together. These classes will all be related in some way – they might all have to do with a specific application or perform a specific set of tasks.
Java is a general-purpose, object-oriented computer programming language that offers special features that allow programs to take advantage of the power and flexibility of the Internet.
Race Class based on Chapter 8 of "Race and Racisms: A Critical Approach."Tanya Golash Boza
Readings for class:
"Education" Chapter 8 of Race and Racisms and Carter, Prudence L. "''Black''Cultural Capital, Status Positioning, and Schooling Conflicts for Low-Income African American Youth." Social Problems 50.1 (2003): 136-155.
This presentation provides an overview of oracle's associate and professional Java certifications - gives you ideas on how to prepare and crack the exam with ease.
Based on chapter 1 of the textbook "Building Java Programs", 3rd edition. Covers binary/decimal number conversion, the programming process, writing your very first program, console output, and procedural decomposition.
See a video presentation of this slideshow on my YouTube channel JavaGoddess, at https://www.youtube.com/watch?v=yYLfN_potQY&t=57s
Comprehensive And Integrated Approach To Project Management And Solution Deli...Alan McSweeney
Describes a complete and integrated approach to solution delivery that encompasses project management, project portfolio management, business analysis and solution architecture and design
Effective solution delivery requires an integrated approach to projects across all key disciplines
Project portfolio management
Project management
Business analysis
Solution design
Having silos of expertise that do not communicate or co-operate leads to significant risk
Project failure tends to be embedded in a project from the start. There is a spectrum of failures from complete collapse to a range of lesser failures associated with behind schedule and over budget. The reasons are all too well known. Yet the lessons from project failures are not being learned and the behaviours that give rise to failures continue to persist. Project failures will continue to occur until the reasons and behaviours are explicitly understood, acknowledged and addressed.
The reasons for project failure across project phases include:
Requirements
• Poor initial requirement definition
• Poor requirements validation
• Poor management of requirements
• Requirements not linked to business benefits
Solution Design
• Solution design not validated
• Solution design not linked to business needs
• Solution design too complex
• Solution design does not capture necessary complexity
• Solution design based on unproven technology
• Solution not implementable
• Underlying business processes not defined adequately
Estimation
• Errors due to limitations in estimating procedures
• Failure to understand and account for technical risks
• Deliberate underestimation/misrepresentation of costs
• Poor inflation estimates
• Top down pressure to reduce estimates
• Lack of valid independent cost estimates
Project Management
• Lack of program management expertise
• Mismanagement/human error
• Over optimism
• Schedule concurrency
• Program stretch outs to keep production lines open
• Lack of communication
• Poor management of change and scope creep
Development and Implementation
• Lack of competition when selecting suppliers, poor supplier selection process
• Poor supplier engagement
• Poor contract design
• Inconsistent contract management/administration procedures, too much or too little oversight
• Waste
• Excess profits by supplier, supplier overstaffed
• Supplier indirect costs unreasonable
• Inadequate resource allocation and prioritisation
• Organisation cannot handle change
Finance and Budgeting
• Business case incomplete
• Funding instabilities caused by trying to fund too many projects
• Funding instabilities caused by management decisions
• Inefficient production rates due to stretching out programmes
• Failure to fund for contingency
• Failure to fund projects at realistic cost
Functional Thinking - Programming with Lambdas in Java 8Ganesh Samarthyam
Functional programming is on the rise. Almost all major and mainstream languages support functional programming features, including C++, Java, Swift, and Python, and Visual Basic. With Java 8’s lambda functions, Java now supports functional programming. Moving to functional programming can result in significantly better code and productivity gains. However, it requires a paradigm shift: you need to move away from imperative and object-oriented thinking to start thinking functionally. That’s what this workshop will help you achieve: it will help you make your shift towards functional programming. The workshop will introduce lambda functions in Java with examples from Java library itself. Presented in OSI Days 2015 workshop - http://osidays.com/osidays/shifting-to-functional-programming-lambdas-for-java-developers/
Forget Big Data. It's All About Smart DataAlan McSweeney
This proposes an initial smart data framework and structure to allow the nuggets of value contained in the deluge of largely irrelevant and useless data to be isolated and extracted. It enables your organisation to ask the questions to understand where it should be in terms of its data state and profile and what it should do to achieve the desired skills level across the competency areas of the framework.
Every organisation operates within a data landscape with multiple sources of data relating to its activities that is acquired, transported, stored, processed, retained, analysed and managed. Interactions across the data landscape generate primary data. When you extend the range of possible interactions business processes outside the organisation you generate a lot more data.
Smart data means being:
• Smart in what data to collect, validate and transform
• Smart in how data is stored, managed, operated and used
• Smart in taking actions based on results of data analysis including organisation structures, roles, devolution and delegation of decision-making, processes and automation
• Smart in being realistic, pragmatic and even skeptical about what can be achieved and knowing what value can be derived and how to maximise value obtained
• Smart in defining an achievable, benefits-lead strategy integrated with the needs business and in its implementation
• Smart in selecting the channels and interactions to include – smart data use cases
Smart data competency areas comprise a complete set of required skills and abilities to design, implement and operate an appropriate smart data programme.
In the given example only one object will be created. Firstly JVM will not fi...Indu32
In the given example only one object will be created. Firstly JVM will not find any string object with the value “Welcome” in the string constant pool, so it will create a new object. After that it will find the string with the value “Welcome” in the pool, it will not create a new object but will return the reference to the same instance. In this article, we will learn about Java Strings.
Variables declared in a Java interface is by default final. An abstract class may contain non-final variables.
Members of a Java interface are public by default. A member of an abstract class can either be private, protected or public.
An interface is absolutely abstract and cannot be instantiated. An abstract class also cannot be instantiated, but can be invoked if it contains a main method.
Lab 1: Recursion
Introduction
Tracery (tracery.io) is a simple text-expansion language made by one of your TAs as a
homework assignment for one of Prof. Mateas's previous courses. It now has tens of
thousands of users, and runs about 7000 chatbots on Twitter (you never know where a
homework will take you!).
Tracery uses context-free grammars
( https://en.wikipedia.org/wiki/Context-free_grammar) to store information about how to
expand rules. A Tracery grammar is a set of keys, each of which has some set of
expansions that can replace it. In our version, the line
"beverage:tea|coffee|cola|milk" means that the symbol "beverage" can be
replaced with any of those four options. You replace a symbol whenever you see it in
hashtags. This rule "#name# drank a glass of #beverage#" will have the "name"
and "beverage" symbols replaced with expansions associated with those symbols. In
the case of the "beverage" rule above, which has four possible expansions, one will be
picked at random. If the replacement rule also has hashtags in it, we replace those, and
if those replacements have hashtags.... we keep replacing things until all the hashtags
are gone, recursively.
In this assignment, you will be implementing a simplified version of Tracery in Java, and
then using it to generate generative text. You will also be writing your own grammar to
generate new texts (hipster cocktails, emoji stories, or nonsense poems).
Outline
● Compile and run a Java program
● Save all the arguments
● Load the Tracery files
● Output all the rules
● Expand rules and print them to the screen
Compile and run a Java program
This program has several files (Rule.java, and TraceryRecursion.java). We can't
run these files as code, as we would with other “interpreted” languages (like Javascript
https://en.wikipedia.org/wiki/Context-free_grammar
or Python). For Java, we need the computer to put them all together and translate it to
machine code, in a process called “compiling”.
You will compile and run your Java program from the command line. When you see $,
this means that it is a command that you will enter in the command line. Windows and
Unix (such as Linux or the Mac terminal) command lines are a little different, be sure
you know the basics of navigating the one you are using.
Do you have Java installed on your machine? What version? Let's find out! Type the
following into your command line: $ javac -version $ java -version You should
have at least Javac 1.8 and Java 1.8 (often called “Java 8”) installed. If that's not the
case, this is a good time to fix that by updating your Java. We will be using some
features of Java 8 in this class.
Compile your java program.
$ javac TraceryRecursion.java
So far, it will compile without errors.
Look in the folder, and you will see that you have a new file TraceryRecursion.class.
This is the compiled version of your file. You can now run ...
JAVA Tutorial- Do's and Don'ts of Java programmingKeshav Kumar
Whether you program regularly in Java, and know it like the back of your hand, or whether you’re new to the language or a casual programmer, you’ll make mistakes. The purpose of this webinar is to talk about some Do's and Don'ts of Java programming.
The webinar will cover the following areas:
- Top 10 mistakes made by Java programmers – How to avoid them
- Core Java- Best Practices – This covers good and bad practices both
- How to prepare for Java Interviews and Sun Java Exams
- Q&A
Key learnings from this webinar:
- It will benefit both junior and senior java professionals so that they don’t make common errors
- Clarity of concepts of Java
- Better awareness of best practices of Java
JAVA Tutorial- Do's and Don'ts of Java programmingKeshav Kumar
Whether you program regularly in Java, and know it like the back of your hand, or whether you’re new to the language or a casual programmer, you’ll make mistakes. The purpose of this webinar is to talk about some Do's and Don'ts of Java programming.
The webinar will cover the following areas:
- Top 10 mistakes made by Java programmers – How to avoid them
- Core Java- Best Practices – This covers good and bad practices both
- How to prepare for Java Interviews and Sun Java Exams
- Q&A
Key learnings from this webinar:
- It will benefit both junior and senior java professionals so that they don’t make common errors
- Clarity of concepts of Java
- Better awareness of best practices of Java
Effective Java - Madde 2: Birçok parametreli yapılandırıcıyla karşılaşırsan k...İbrahim Kürce
Statik fabrikalar ve yapılandırıcılar ortak bir kısıtı paylaşır: birçok isteğe bağlı parametreye karşı kendilerini iyi ölçekleyemezler. Paketli gıdaların üzerinde bulunan Beslenme Unsurları(Nutrition Facts) sınıfının gösterilmesi ele alalım. Bu sınıfın birkaç tane zorunlu alanı vardır: porsiyon boyutu(serving size), konteyner başına porsiyon(servings per container) ve porsiyon başına kalorileri(calories per serving). Ayrıca birçok isteğe bağlı alanı vardır: toplam yağ(total fat), doymuş yağ(saturated fat), kolesterol, sodyum vb. Birçok ürün için bu alanların değerleri sıfırdan farklıdır.
Effective Java - Madde 1: Yapılandırıcılar yerine statik fabrika(factory) met...İbrahim Kürce
Normal şekilde, sınıfı kullanan kişi, o sınıftan bir örnek oluşturabilme iznini public(herkese açık) yapılandırıcı sayesinde elde eder. Her programcının bilmesi gereken başka bir teknik daha vardır. Bir sınıf, kendi örneğini döndüren statik fabrika metodu ile de örneğini oluşturabilir. Boolean(basit boolean tipinin kutulanmış sınıf hali) sınıfından basit bir örnek.
Effective Java - Chapter 4: Classes and Interfacesİbrahim Kürce
Classes and interfaces lie at the heart of the Java programming language. They are its basic units of abstraction.
This chapter contains guidelines to help you make the best use of these elements so that your classes and interfaces are usable, robust, and flexible.
Effective Java - Chapter 3: Methods Common to All Objectsİbrahim Kürce
Although object is a concrete class, it is designed primarily for extension.
All of its nonfinal methods (equals, hashCode, toString, clone, and finalize) have explicit general contracts because they are designed to be overridden.
This chapter tells you when and how to override the nonfinal Object methods. The finalize method is omitted from this chapter because it was discussed in Item 7. While not an Object method, Comparable.compareTo is discussed in this chapter because it has a similar character.
Effective Java - Chapter 2: Creating and Destroying Objectsİbrahim Kürce
Creating and Destroying Objects: This chapter concerns creating and destroying objects: when and how to create them, when and how to avoid creating them, how to ensure they are destroyed in a timely manner, and how to manage any cleanup actions that must precede their destruction.
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.
Cyaniclab : Software Development Agency Portfolio.pdfCyanic lab
CyanicLab, an offshore custom software development company based in Sweden,India, Finland, is your go-to partner for startup development and innovative web design solutions. Our expert team specializes in crafting cutting-edge software tailored to meet the unique needs of startups and established enterprises alike. From conceptualization to execution, we offer comprehensive services including web and mobile app development, UI/UX design, and ongoing software maintenance. Ready to elevate your business? Contact CyanicLab today and let us propel your vision to success with our top-notch IT solutions.
Quarkus Hidden and Forbidden ExtensionsMax Andersen
Quarkus has a vast extension ecosystem and is known for its subsonic and subatomic feature set. Some of these features are not as well known, and some extensions are less talked about, but that does not make them less interesting - quite the opposite.
Come join this talk to see some tips and tricks for using Quarkus and some of the lesser known features, extensions and development techniques.
In 2015, I used to write extensions for Joomla, WordPress, phpBB3, etc and I ...Juraj Vysvader
In 2015, I used to write extensions for Joomla, WordPress, phpBB3, etc and I didn't get rich from it but it did have 63K downloads (powered possible tens of thousands of websites).
Experience our free, in-depth three-part Tendenci Platform Corporate Membership Management workshop series! In Session 1 on May 14th, 2024, we began with an Introduction and Setup, mastering the configuration of your Corporate Membership Module settings to establish membership types, applications, and more. Then, on May 16th, 2024, in Session 2, we focused on binding individual members to a Corporate Membership and Corporate Reps, teaching you how to add individual members and assign Corporate Representatives to manage dues, renewals, and associated members. Finally, on May 28th, 2024, in Session 3, we covered questions and concerns, addressing any queries or issues you may have.
For more Tendenci AMS events, check out www.tendenci.com/events
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
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!
Paketo Buildpacks : la meilleure façon de construire des images OCI? DevopsDa...Anthony Dahanne
Les Buildpacks existent depuis plus de 10 ans ! D’abord, ils étaient utilisés pour détecter et construire une application avant de la déployer sur certains PaaS. Ensuite, nous avons pu créer des images Docker (OCI) avec leur dernière génération, les Cloud Native Buildpacks (CNCF en incubation). Sont-ils une bonne alternative au Dockerfile ? Que sont les buildpacks Paketo ? Quelles communautés les soutiennent et comment ?
Venez le découvrir lors de cette session ignite
Climate Science Flows: Enabling Petabyte-Scale Climate Analysis with the Eart...Globus
The Earth System Grid Federation (ESGF) is a global network of data servers that archives and distributes the planet’s largest collection of Earth system model output for thousands of climate and environmental scientists worldwide. Many of these petabyte-scale data archives are located in proximity to large high-performance computing (HPC) or cloud computing resources, but the primary workflow for data users consists of transferring data, and applying computations on a different system. As a part of the ESGF 2.0 US project (funded by the United States Department of Energy Office of Science), we developed pre-defined data workflows, which can be run on-demand, capable of applying many data reduction and data analysis to the large ESGF data archives, transferring only the resultant analysis (ex. visualizations, smaller data files). In this talk, we will showcase a few of these workflows, highlighting how Globus Flows can be used for petabyte-scale climate analysis.
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.
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.
How to Position Your Globus Data Portal for Success Ten Good PracticesGlobus
Science gateways allow science and engineering communities to access shared data, software, computing services, and instruments. Science gateways have gained a lot of traction in the last twenty years, as evidenced by projects such as the Science Gateways Community Institute (SGCI) and the Center of Excellence on Science Gateways (SGX3) in the US, The Australian Research Data Commons (ARDC) and its platforms in Australia, and the projects around Virtual Research Environments in Europe. A few mature frameworks have evolved with their different strengths and foci and have been taken up by a larger community such as the Globus Data Portal, Hubzero, Tapis, and Galaxy. However, even when gateways are built on successful frameworks, they continue to face the challenges of ongoing maintenance costs and how to meet the ever-expanding needs of the community they serve with enhanced features. It is not uncommon that gateways with compelling use cases are nonetheless unable to get past the prototype phase and become a full production service, or if they do, they don't survive more than a couple of years. While there is no guaranteed pathway to success, it seems likely that for any gateway there is a need for a strong community and/or solid funding streams to create and sustain its success. With over twenty years of examples to draw from, this presentation goes into detail for ten factors common to successful and enduring gateways that effectively serve as best practices for any new or developing gateway.
Innovating Inference - Remote Triggering of Large Language Models on HPC Clus...Globus
Large Language Models (LLMs) are currently the center of attention in the tech world, particularly for their potential to advance research. In this presentation, we'll explore a straightforward and effective method for quickly initiating inference runs on supercomputers using the vLLM tool with Globus Compute, specifically on the Polaris system at ALCF. We'll begin by briefly discussing the popularity and applications of LLMs in various fields. Following this, we will introduce the vLLM tool, and explain how it integrates with Globus Compute to efficiently manage LLM operations on Polaris. Attendees will learn the practical aspects of setting up and remotely triggering LLMs from local machines, focusing on ease of use and efficiency. This talk is ideal for researchers and practitioners looking to leverage the power of LLMs in their work, offering a clear guide to harnessing supercomputing resources for quick and effective LLM inference.
Providing Globus Services to Users of JASMIN for Environmental Data AnalysisGlobus
JASMIN is the UK’s high-performance data analysis platform for environmental science, operated by STFC on behalf of the UK Natural Environment Research Council (NERC). In addition to its role in hosting the CEDA Archive (NERC’s long-term repository for climate, atmospheric science & Earth observation data in the UK), JASMIN provides a collaborative platform to a community of around 2,000 scientists in the UK and beyond, providing nearly 400 environmental science projects with working space, compute resources and tools to facilitate their work. High-performance data transfer into and out of JASMIN has always been a key feature, with many scientists bringing model outputs from supercomputers elsewhere in the UK, to analyse against observational or other model data in the CEDA Archive. A growing number of JASMIN users are now realising the benefits of using the Globus service to provide reliable and efficient data movement and other tasks in this and other contexts. Further use cases involve long-distance (intercontinental) transfers to and from JASMIN, and collecting results from a mobile atmospheric radar system, pushing data to JASMIN via a lightweight Globus deployment. We provide details of how Globus fits into our current infrastructure, our experience of the recent migration to GCSv5.4, and of our interest in developing use of the wider ecosystem of Globus services for the benefit of our user community.
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.
Gamify Your Mind; The Secret Sauce to Delivering Success, Continuously Improv...Shahin Sheidaei
Games are powerful teaching tools, fostering hands-on engagement and fun. But they require careful consideration to succeed. Join me to explore factors in running and selecting games, ensuring they serve as effective teaching tools. Learn to maintain focus on learning objectives while playing, and how to measure the ROI of gaming in education. Discover strategies for pitching gaming to leadership. This session offers insights, tips, and examples for coaches, team leads, and enterprise leaders seeking to teach from simple to complex concepts.
In software engineering, the right architecture is essential for robust, scalable platforms. Wix has undergone a pivotal shift from event sourcing to a CRUD-based model for its microservices. This talk will chart the course of this pivotal journey.
Event sourcing, which records state changes as immutable events, provided robust auditing and "time travel" debugging for Wix Stores' microservices. Despite its benefits, the complexity it introduced in state management slowed development. Wix responded by adopting a simpler, unified CRUD model. This talk will explore the challenges of event sourcing and the advantages of Wix's new "CRUD on steroids" approach, which streamlines API integration and domain event management while preserving data integrity and system resilience.
Participants will gain valuable insights into Wix's strategies for ensuring atomicity in database updates and event production, as well as caching, materialization, and performance optimization techniques within a distributed system.
Join us to discover how Wix has mastered the art of balancing simplicity and extensibility, and learn how the re-adoption of the modest CRUD has turbocharged their development velocity, resilience, and scalability in a high-growth environment.
First Steps with Globus Compute Multi-User EndpointsGlobus
In this presentation we will share our experiences around getting started with the Globus Compute multi-user endpoint. Working with the Pharmacology group at the University of Auckland, we have previously written an application using Globus Compute that can offload computationally expensive steps in the researcher's workflows, which they wish to manage from their familiar Windows environments, onto the NeSI (New Zealand eScience Infrastructure) cluster. Some of the challenges we have encountered were that each researcher had to set up and manage their own single-user globus compute endpoint and that the workloads had varying resource requirements (CPUs, memory and wall time) between different runs. We hope that the multi-user endpoint will help to address these challenges and share an update on our progress here.
First Steps with Globus Compute Multi-User Endpoints
OCA Java SE 8 Exam Chapter 3 Core Java APIs
1. OCA EXAM 8
CHAPTER 3 – Core Java APIs
By İbrahim Kürce
Brief of OCA: Oracle Certified Associate Java SE 8 Programmer I Study Guide: Exam 1Z0-808
Jeanne Boyarsky, Scott Selikoff
2. Core Java APIs
The OCA exam expects you to know the core data structures and classes
used in Java, and in this chapter readers will learn about the most common
methods available. For example, String and StringBuilder are used for text
data. An array and an ArrayList are used when you have multiple values. A
variety of classes are used for working with dates. In this chapter, you'll also
learn how to determine whether two objects are equal.
API stands for application programming interface. In Java, an interface is
something special. In the context of an API, it can be a group of class or
interface definitions that gives you access to a service or functionality.
3. Strings
A string is basically a sequence of characters; here's an example:
4. String Concatenation
The OCA exam creators like string concatenation because the + operator
can be used in two ways within the same line of code. There aren't a lot of
rules to know for this, but you have to know them well:
If both operands are numeric, + means numeric addition.
If either operand is a String, + means concatenation.
The expression is evaluated left to right.
5. String Concatenation
There is only one more thing to know about concatenation, but it is an easy
one. In this example, you just have to remember what + = does. s + = "2"
means the same thing as s = s + “2".
To review the rules one more time: use numeric addition if two numbers are
involved, use concatenation otherwise, and evaluate from left to right.
6. Immutability
Once a String object is created, it is not allowed to change. It cannot be
made larger or smaller, one of the characters inside it. and you cannot
change
Mutable is another word for changeable. Immutable is the opposite— an
object that can't be changed once it's created. On the OCA exam, you
need to know that String is immutable.
7. The String Pool
Since strings are everywhere in Java, they use up a lot of memory. In some
production applications, they can use up 25– 40 percent of the memory in
the entire program. Java realizes that many strings repeat in the program
and solves this issue by reusing common ones. The string pool, also known
as the intern pool, is a location in the Java virtual machine (JVM) that
collects all these strings.
The former says to use the string pool normally. The second says “No, JVM. I
really don't want you to use the string pool. Please create a new object for
me even though it is less efficient.”
8. Important String Methods
The String class has dozens of methods. Luckily, you need to know only a
handful for the exam.
length() The method length() returns the number of characters in the String. The
method signature is as follows: int length().
charAt() The method charAt() lets you query the string to find out what
character is at a specific index. The method signature is as follows: char
charAt(int index).
indexOf() The method indexOf() looks at the characters in the string and finds
the first index that matches the desired value. indexOf can work with an
individual character or a whole String as input. It can also start from a requested
position.
10. Important String Methods
substring() The method substring() also looks for characters in a string. It
returns parts of the string. The first parameter is the index to start with for the
returned string. As usual, this is a zero-based index.
toLowerCase() and toUpperCase() After that mental exercise, it is nice to
have methods that do exactly what they sound like!
11. Important String Methods
equals() and equalsIgnoreCase() The equals() method checks whether two
String objects contain exactly the same characters in the same order. The
equalsIgnoreCase() method checks whether two String objects contain the
same characters with the exception that it will convert the characters' case
if needed.
startsWith() and endsWith() The startsWith() and endsWith() methods look at
whether the provided value matches part of the String.
contains() The contains() method also looks for matches in the String.
replace() The replace() method does a simple search and replace on the
string.
12. Important String Methods
trim() The trim() method removes whitespace from the beginning and end
of a String.
Method Chaining
13. Using the StringBuilder Class
This sequence of events continues, and after 26 iterations through the loop,
a total of 27 objects are instantiated, most of which are immediately
eligible for garbage collection.
This is very inefficient. The StringBuilder class creates a String without storing
all those interim String values. Unlike the String class, StringBuilder is not
immutable.
14. Mutability and Chaining
When we chained String method calls, the result was a new String with the
answer. Chaining StringBuilder objects doesn't work this way. Instead, the
StringBuilder changes its own state and returns a reference to itself!
Did you say both print "abcdefg"? Good. There's only one StringBuilder
object here.
15. Creating a StringBuilder
Size vs. Capacity
Size is the number of characters currently in the sequence, and capacity is
the number of characters the sequence can currently hold. Since a String is
immutable, the size and capacity are the same. The number of characters
appearing in the String is both the size and capacity.
16. Important StringBuilder Methods
charAt(), indexOf(), length(), and substring() These four methods work
exactly the same as in the String class.
append() It adds the parameter to the StringBuilder and returns a reference
to the current StringBuilder.
StringBuilder append( String str)
Notice that we said one of the method signatures. There are more than 10
method signatures.
insert() The insert() method adds characters to the StringBuilder at the
requested index and returns a reference to the current StringBuilder.
17. Important StringBuilder Methods
delete() and deleteCharAt() The delete() method is the opposite of the
insert() method. It removes characters from the sequence and returns a
reference to the current StringBuilder. The deleteCharAt() method is
convenient when you want to delete only one character.
reverse() It reverses the characters in the sequences and returns a
reference to the current.
toString() The last method converts a StringBuilder into a String.
18. StringBuilder vs. StringBuffer
StringBuilder was added to Java in Java 5. If you come across older code,
you will see StringBuffer used for this purpose. StringBuffer does the same
thing but more slowly because it is thread safe.
In theory, you don't need to know about StringBuffer on the exam at all.
20. Understanding Equality
This works because the authors of the String class implemented a standard
method called equals to check the values inside the String rather than the
String itself. If a class doesn't have an equals method, Java determines
whether the references point to the same object— which is exactly what =
= does.
In case you are wondering, the authors of StringBuilder did not implement
equals(). If you call equals() on two StringBuilder instances, it will check
reference equality.
21. Understanding Java Arrays
An array is an area of memory on the heap with space for a designated
number of elements.
A String is implemented as an array with some methods that you might
want to use when dealing with characters specifically.
A StringBuilder is implemented as an array where the array object is
replaced with a new bigger array object when it runs out of space to store
all the characters.
In other words, an array is an ordered list. It can contain duplicates. You will
learn about data structures that cannot contain duplicates for the OCP
exam.
23. Creating an Array of Primitives
All four of these statements do the exact same thing:
int[] ids, types; // two variables of type int[].
int ids[], types; // This time we get one variable of type int[] and one
variable of type int. Be careful on exam.
24. Creating an Array with Reference
Variables
You can choose any Java type to be the type of the array.
We can call equals() because an array is an object. It returns true because
of reference equality.
int is a primitive; int[] is an object.
You don't have to know this for the exam, but [L means it is an array,
java.lang.String is the reference type, and 160bc7c0 is the hash code.
Note:Since Java 5, Java has provided a method that prints an array nicely:
java.util.Arrays.toString( bugs) would print [cricket, beetle, ladybug]. Not on
exam.
25. Creating an Array with Reference
Variables
You wanted to force a bigger type into a smaller type
At line 7, at runtime, the code throws an ArrayStoreException. You don't
need to memorize the name of this exception, but you do need to know
that the code will throw an exception.
26. Using an Array
The exam will test whether you are being observant by trying to access
elements that are not in the array. Can you tell why each of these throws
an ArrayIndexOutOfBoundsException for our array of size 10?
The length is always one more than the maximum valid index. Finally, the for
loop incorrectly uses < = instead of <, which is also a way of referring to that
10th element.
27. Sorting
You can pass almost any array to Arrays.sort().
import java.util.* // import whole package including Arrays
import java.util.Arrays; // import just Arrays
This code outputs 10 100 9.
28. Searching
Java also provides a convenient way to search— but only if the array is already
sorted.
3 isn't in the list, it would need to be inserted at element 1 to preserve the sorted
order. We negate and subtract 1 for consistency, getting –1 –1, also known as –
2.
29. Multidimensional Arrays
Arrays are objects, and of course array components can be objects.
String [][] rectangle = new String[ 3][ 2];
30. Multidimensional Arrays
While that array happens to be rectangular in shape, an array doesn't
need to be. Consider this one:
int[][] differentSize = {{1, 4}, {3}, {9, 8, 7}};
Another way to create an asymmetric array is to initialize just an array's first
dimension, and define the size of each array component in a separate
statement:
32. Understanding an ArrayList
An array has one glaring shortcoming: you have to know how many
elements will be in the array when you create it and then you are stuck
with that choice. Just like a StringBuilder, ArrayList can change size at
runtime as needed. Like an array, an ArrayList is an ordered sequence that
allows duplicates.
import java.util.* // import whole package including ArrayList
import java.util.ArrayList; // import just ArrayList
Remember that if you are shown a code snippet with a line number that
doesn't begin with 1, you can assume the necessary imports are there.
33. ArrayList
As with StringBuilder, there are three ways to create an ArrayList:
The first says to create an ArrayList containing space for the default number
of elements but not to fill any slots yet. The second says to create an
ArrayList containing a specific number of slots, but again not to assign any.
The final example tells Java that we want to make a copy of another
ArrayList.
Java 5 introduced generics,
34. ArrayList
Starting in Java 7, you can even omit that type from the right side.
ArrayList implements an interface called List. In other words, an ArrayList is a
List.
35. ArrayList Methods
You are going to see something new in the method signatures: a “class”
named E. E is used by convention in generics to mean “any class that this
array can hold.” If you didn't specify a type when creating the ArrayList, E
means Object.
add() The add() methods insert a new value in the ArrayList. The method
signatures are as follows:
Don't worry about the boolean return value. It always returns true.
36. ArrayList Methods
remove() The remove() methods remove the first matching value in the
ArrayList or remove the element at a specified index.
Since calling remove() with an int uses the index, an index that doesn't exist
will throw an exception. For example, birds.remove( 100) throws an
IndexOutOfBoundsException.
37. ArrayList Methods
set() The set() method changes one of the elements of the ArrayList without
changing the size.
isEmpty() and size() The isEmpty() and size() methods look at how many of
the slots are in use.
clear() The clear() method provides an easy way to discard all elements of
the ArrayList.
contains() The contains() method checks whether a certain value is in the
ArrayList. This method calls equals() on each element of the ArrayList.
38. ArrayList Methods
equals() Finally, ArrayList has a custom implementation of equals() so you
can compare two lists to see if they contain the same elements in the same
order.
39. Wrapper Classes
Up to now, we've only put String objects in the ArrayList. What happens if
we want to put primitives in? Each primitive type has a wrapper class,
which is an object type that corresponds to the primitive.
40. Wrapper Classes
The first line converts a String to an int primitive. The second converts a
String to an Integer wrapper class.
The Character class doesn't participate in the parse/ valueOf methods.
41. Autoboxing
Since Java 5, you can just type the primitive value and Java will convert it to the
relevant wrapper class for you. This is called autoboxing.
It actually outputs 1.
If you want to remove the 2, you can write numbers.remove( new Integer( 2)) to
force wrapper class use.
42. Converting Between array and List
You should know how to convert between an array and an ArrayList.
The advantage of specifying a size of 0 for the parameter is that Java will
create a new array of the proper size for the return value.
The original array and created array backed List are linked. When a
change is made to one, it is available in the other. It is a fixed-size list and is
also known a backed List because the array changes with it.
43. Sorting
Sorting an ArrayList is very similar to sorting an array. You just use a different
helper class:
44. Working with Dates and Times
In Java 8, Oracle completely revamped how we work with dates and times.
Just know that the “old way” is not on the exam.
You need an import statement to work with the date and time classes. Most of
them are in the java.time package. import java.time.*;
The exam doesn't cover time zones.
LocalDate Contains just a date— no time and no time zone. A good example of
LocalDate is your birthday this year. It is your birthday for a full day regardless of
what time it is.
LocalTime Contains just a time— no date and no time zone. A good example of
LocalTime is midnight. It is midnight at the same time every day.
LocalDateTime Contains both a date and time but no time zone. A good
example of LocalDateTime is “the stroke of midnight on New Year's.” Midnight
on January 2 isn't nearly as special, and clearly an hour after midnight isn't as
special either.
45. Dates and Times
If you do need to communicate across time zones, ZonedDateTime handles
them.
The first one contains only a date and no time. The second contains only a
time and no date. This time displays hours, minutes, seconds, and
nanoseconds. The third contains both date and time. Java uses T to
separate the date and time when converting LocalDateTime to a String.
46. Dates and Times
It is good to use the Month constants (to make the code easier to read),
you can pass the int number of the month directly.
For months in the new date and time methods, Java counts starting from 1
like we human beings do.
You can specify just the hour and minute, or you can add the number of
seconds. You can even add nanoseconds if you want to be very precise.
Finally, we can combine dates and times:
47. Dates and Times
The date and time classes have private constructors to force you to use the
static methods. The exam creators may try to throw something like this at
you:
48. Manipulating Dates and Times
The date and time classes are immutable, just like String was.
There are also nice easy methods to go backward in time.
49. Manipulating Dates and Times
It is common for date and time methods to be chained.
The exam also may test to see if you remember what each of the date and
time objects includes.
50. Working with Periods
Period period = Period.ofMonths( 1); // create a period
Period annually = Period.ofYears( 1); // every 1 year
Period quarterly = Period.ofMonths( 3); // every 3 months
Period everyThreeWeeks = Period.ofWeeks( 3); // every 3 weeks
You cannot chain methods when creating a Period.
Period wrong = Period.ofYears( 1). ofWeeks( 1); // every week
There is also Duration, which is intended for smaller units of time.
Duration isn't on the exam since it roughly works the same way as Period.
51. Converting to a long
LocalDate has toEpochDay(), which is the number of days since January 1,
1970.
LocalDateTime has toEpochTime(), which is the number of seconds since
January 1, 1970.
LocalTime does not have an epoch method.
52. Formatting Dates and Times
The date and time classes support many methods to get data out of them:
It would be more work than necessary. Java provides a class called
DateTimeFormatter to help us out.
53. Formatting Dates and Times
Predefined formats
There are two predefined formats that can show up on the exam: SHORT
and MEDIUM. The other predefined formats involve time zones, which are
not on the exam.
If you don't want to use one of the predefined formats, you can create
your own.
55. Parsing Dates and Times.
Now that you know how to convert a date or time to a formatted String,
you'll find it easy to convert a String to a date or time. Just like the format()
method, the parse() method takes a formatter as well. If you don't specify
one, it uses the default for that type.