99-problems/java8 at master · shekhargulati/99-problems. 99-problems/java8 at master · shekhargulati/99-problems. Setting Up A MacBook Pro for Java Development. Well, I went to the “dark” side and acquired a MacBook Pro to use it for development when I am not at my PC.
Annotations in Java provide a means to describe classes, fields, and methods. Essentially, they are a form of metadata added to a Java source file, they can’t affect the semantics of a program directly. However, annotations can be read at run-time using Reflection & this process is known as Introspection. Then it could be used to modify classes, fields, or methods. This feature is often exploited by Libraries & SDKs (hibernate, JUnit, Spring Framework) to simplify or reduce the amount of code that a programmer would otherwise do in order to work with these Libraries or SDKs.Therefore, it’s fair to say Annotations and Reflection work hand-in hand in Java.
We also get to limit the availability of an annotation to either compile-time or runtime. 01. 02. 03. Seven tips to becoming a Java developer Zen master. Putting aside his Diabolical Developer identity and appearing as Zen master, Martijn Verburg laid out dos and don'ts for Java developers in parables at JavaOne 2015 in San Francisco.
He even dressed the part, in traditional Zen black pants, and shirt and sandals. Verburg, CEO at jClarity Ltd. -- a London-based seller of app performance diagnostic services -- adapted the session, with permission, from the writings of Qi the Scribe on The Codeless Code site, which presents illustrated fables, or Zen koans, on the art and philosophy of software development.
In each fable Verburg told, a Zen software master teaches his students, or monks, the core elements of software development. Most often, the monks learn their lessons the hard way. The Four Month Bug: JVM statistics cause garbage collection pauses (evanjones.ca) [ 2015-March-24 16:56 ] TL;DR: The JVM by default exports statistics by mmap-ing a file in /tmp (hsperfdata).
On Linux, modifying a memory mapped file can block until disk I/O completes, which can be hundreds of milliseconds. Since the JVM modifies these statistics during garbage collection and safepoints, this causes pauses that are hundreds of milliseconds long. To reduce worst-case pause latencies, add the -XX:+PerfDisableSharedMem JVM flag to disable this feature. Let’s Get to the Rapids: Java 8 Stream Performance. Multithreading and Concurrency Interview Questions and Answers – The ULTIMATE List (PDF Download) EDITORIAL NOTE: Concurrency is always a challenge for developers and writing concurrent programs can be extremely hard.
There is a number of things that could potentially blow up and the complexity of systems rises considerably when concurrency is introduced. However, the ability to write robust concurrent programs is a great tool in a developer’s belt and can help build sophisticated, enterprise level applications. In this article we will discuss different types of questions that can be used in a programming interview in order to assess a candidate’s understanding of concurrency and multithreading. The questions are not only Java specific, but revolve around general programming principles. Enjoy! JavaSpecialists.EU: Java Courses & Java Specialists Newsletter. Java Bytecode: Bending the Rules. Tuning Java Garbage Collection for Spark Applications. This is a guest post from our friends in the SSG STO Big Data Technology group at Intel.
Join us at the Spark Summit to hear from Intel and other companies deploying Spark in production. Use the code Databricks20 to receive a 20% discount! Spark is gaining wide industry adoption due to its superior performance, simple interfaces, and a rich library for analysis and calculation. Like many projects in the big data ecosystem, Spark runs on the Java Virtual Machine (JVM). 11 Best Websites for Java Developers. Want to become a Java developer?
Java is one of the most popular programming languages in computing platform. Today, over the internet, there are a vast number of websites which provide basic to advance information related to Java. Developer are always looking for website which they can refer for topics, tips, tricks, tutorials and the latest technologies related to Java, as well as Mobile Java, Java App Dev, java Tips and Core java. People often get confused in finding the best website for Java. But don’t worry, I have done your job by collecting 11 best websites for Java developers from which you can learn and refer it any time.
Oracle Developer Javaworld. Reduce Boilerplate Code in your Java applications with Project Lombok. One of the most frequently voiced criticisms of the Java programming language is the amount of Boilerplate Code it requires.
This is especially true for simple classes that should do nothing more than store a few values. You need getters and setters for these values, maybe you also need a constructor, overridingequals() and hashcode() is often required and maybe you want a more useful toString()implementation. In the end you might have 100 lines of code that could be rewritten with 10 lines of Scala or Groovy code. Java IDEs like Eclipse or IntelliJ try to reduce this problem by providing various types of code generation functionality. However, even if you do not have to write the code yourself, you always see it (and get distracted by it) if you open such a file in your IDE.
Project Lombok (don't be frightened by the ugly web page) is a small Java library that can help reducing the amount of Boilerplate Code in Java Applications. 1. 2. 3 Common SQL Mistakes You are Probably Making as a Java Developer. A regular work week for Java developers might see them coding to develop a scalable web application, creating a dynamic website, developing efficient eCommerce product pages or probably developing an Android app.
Yes, more often than not, they will be working on diverse projects, but with one common thread – coding. Their career demands long working hours and extensive knowledge of coding. Java developers also need to understand project requirements, design and develop a prototype for the assigned project, keep themselves updated with the latest changes happening in the programming industry and also have basic knowledge of other languages like HTML, SQL and many more!
10 Best Java Tools That Every Java Programmers Should Know. Computer development is all based on a resource called Language.
The way we interact, the computer also interacts with us, on the basis of a language. Why Build Your Java Projects with Gradle Rather than Ant or Maven? For years, builds had the simple requirements of compiling and packaging software. But the landscape of modern software development has changed, and so have the needs for build automation. Create Java project with Maven Example. In this tutorial, we will show you an easy way to create a single Java project, using Apache Maven. Also, we will transform our project, in order to be recognizable and supported by the Eclipse IDE. Finally, we will conclude the tutorial, by presenting how we can package our Java project into an executable “.jar” file. Scala for Java Developers. December 16, 2014Past SessionsComments Off - What are the major advantages/features Scala provides - Why should someone move from Java to Scala - What is the future direction of Scala This is one of 4 session in Dec, investigating other JVM Languages Speaker: Dick Wall.
7 New Tools Java Developers Should Know. JClarity – Performance Monitoring Launched last September, JClarity is now offering two products around Java performance: Illuminate and Censum. Illuminate is a performance monitoring tool, while Censum is an application focused on garbage collection logs analysis. More than just collecting data or visualizing it, both tools provide actionable insights to solve the issues they detect. “What we want to do is to move the problem from data collection to data analysis and insight” – JClarity Co-Founder Ben Evans. Key features: Bottleneck detection (Disk I/O, Garbage Collection, Deadlocks, and more).Action plan – Recommendations to solve the problem, such as “The application needs to increase the number of active threads”.Explanation – Defining the problem in general and the common causes for it, for example “A high percentage of time spent paused in GC may mean that the heap has been under-sized”.
Use selector-syntax to find elements: jsoup Java HTML parser. Thoughts on Java: Java Weekly 49: Java doesn't suck, annotations everywhere, free ebooks and more... The Java world is evolving at a rapid pace and it can be challenging to keep track of it. Fortunately lots of great resources are created every week, explaining new features or looking at existing stuff from a different angle. I am using the Java Weekly series to collect the most interesting links I found during the last week and present them to you all in one place. I hope you find it useful and that it makes it easier for you to keep up-to-date. The Java Posse.
Planet JDK. The heart of the Java developer community. Java for Everything. DbUtils - JDBC Utility Component. A Simple Use-case Comparison of JVM Libraries for MongoDB. MongoDB is one of my favorite data stores when it comes to storing document-based JSON data. Communicating with MongoDB with JVM languages can be done in a lot of ways. I thought it would be a nice exercise to take 4 of the most popular solutions and implement a simple use case in each of those solutions. The use case: create a REST service that can get a list of cities and get the nearest city for a given city with the distance to that city. The 4 approaches I’ll compare are using the standard MongoDB Java Driver, Jongo, Morphia and finally Spring Data for MongoDB. CFR - yet another java decompiler. Running Multiple JDKs on OSX. I often need to have multiple versions of Java installed on my machine.
Some projects I work on use an older version of Java (for e.g, 1.6), whilst I also like to dabble with the latest and greatest version to see what features are looming on the horizon. As I use OSX extensively, I have traditionally fulfilled this requirement by using Virtual Machines either through vmware fusion or through virtual box. However, the biggest downfall with this approach is the performance of running VMs as they can be quite resource intensive. Also, I like working in a native OSX environment, and I don't really like the context switching that occurs when using a VM.