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.

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

May 11th, 2019 by App Shah 33

Enums are lists of constants. When you need a predefined list of values which do represent some kind of numeric or textual data, you should use an enum. For instance, in a chess game you ...
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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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How to create executable .jar file using Linux commands and without Eclipse Shortcut?

March 30th, 2019 by App Shah

So far for me it it was so easy to right click in Eclipse IDE and create executable .jar file with few simple clicks. Last week I had to create executable .jar file manually on my Digital ...
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What is Lock(), UnLock(), ReentrantLock(), TryLock() and How it’s different from Synchronized Block in Java?

March 23rd, 2019 by App Shah

In this tutorial we will go over Lock(), UnLock(), ReentrantLock(), TryLock() and how it's different from Synchronized Block in Java. If you have also below questions then you are at ...
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