Java and J2EE Tutorials Archives...

One of my favorite language Java is a programming language and computing platform developed by Sun which is acquired by Oracle now. J2EE is Java Enterprise Edition, which consists of core Java with a powerful set of libraries.

On Crunchify, we do have more than 400+ Java and J2EE tips with additional production ready utilities. Explore all tutorials below.

In Java How to Get Random Element from ArrayList and ThreadLocalRandom Usage

June 16th, 2019 by App Shah 2

Java is pretty amazing. Sometimes during mock testing you may need to generate Random number like Integer or Double or Long or String from ArrayList. In this tutorial we will create ...
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How to use Spring Framework StopWatch() to Log ExecutionTime and ElapseTime of any Java Thread

June 2nd, 2019 by App Shah 3

Spring Framework - StopWatch() is a very handy utility for any Java developer if you have small Java application or production ready application. Most of the Java applications involve Thread ...
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How to fix UnsupportedClassVersionError: Class has been compiled by a more recent version of the Java Runtime

May 11th, 2019 by App Shah

Today after installing Java 12 on my laptop, I started seeing some issue about compiler version mismatch. In this tutorial we will go over steps on how to fix these ...
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JVM Tuning: Heapsize, Stacksize and Garbage Collection Fundamental

May 10th, 2019 by App Shah 16

Heap Size: When a Java program starts, Java Virtual Machine gets some memory from Operating System. Java Virtual Machine or JVM uses this memory for all its need and part of this memory is ...
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Java File Copy Example – Simple way to Copy File in Java

May 11th, 2019 by App Shah 6

This example illustrates how to copy contents from one file to another file. This topic is related to the I/O (input/output) of java.io.File package. Java.io class represents a file name ...
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Beginner’s Guide to Java eNum – Why and for What should I use Enum? Java Enum Examples

June 30th, 2019 by App Shah 34

Enums are lists of constants like unchangeable variables. Have you heard of Final keyword? It's like that. When you need a predefined list of values which do represent some kind of ...
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How to Create Your Own Non-Blocking, Fixed Size Queue in Java? Same as EvictingQueue

April 19th, 2019 by App Shah

If you don't want to use Google Guava's EvictingQueue external dependency in your Java Enterprise Project then you should consider creating your own non-blocking, fixed size ...
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Java Iterator: OutOfMemory (OOM) Scenario

May 11th, 2019 by App Shah 2

This simple example explains how to iterate through Java Iterator and avoid possible OutOfMemory (OOM) in Java. This post is filed under Java Web Tutorial. Possible reason: forget to use ...
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Everything about Java12 – New Features, Security and Switch Expression Statement (Examples)

April 11th, 2019 by App Shah

On 19th March 2019 Java12 was released. As we know Java12 was part of rapid release, it was released just in 6 months after Java11 release. In this tutorial, we will go over all changes ...
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