Annotations provide information about java elements. Annotations can be interpreted by compiler or IDE at compile time or by JVM at runtime. Annotations can be usedto show attributes of an element: e.g. @Deprecated, @Override, or @NotNullto describe the purpose of an element of the framework, e.g. @Entity, @TestCase, @WebServiceto describe the behavior of an element: @Statefull, @TransactionBefore Java 5, XML was primarily used to store information about java objects, with annotations, this information can be stored within the java code itself.

Following are the steps to use native methods.Create a header file (.h file) for a CPP program.Create CPP fileCreate a DLLIn java code, declare the method as native, load the DLL using System.loadLibrary() method and call the method.

Native methods are written in a different language than java and are declared as native in Java.

The native keyword is used to declare a method as native. It means that method implementation is present in the different language.

Following example is converting a String to int.ExampleLive Demopublic class Tester {    public static void main(String[] args) {       String intString = "1234";       int value = new Integer(intString).intValue();       System.out.println(value);    } }Output1234

You can use JSTL, JSP Standard Tag Library or EL, Expression Language to avoid scriptlets.

Call by Value means calling a method with a parameter as value. Through this, the argument value is passed to the parameter.While Call by Reference means calling a method with a parameter as a reference. Through this, the argument reference is passed to the parameter.In call by value, the modification done to the parameter passed does not reflect in the caller's scope while in the call by reference, the modification done to the parameter passed are persistent and changes are reflected in the caller's scope.But Java uses only call by value. It creates a copy of references and pass them ... Read More

HashMap is non-syncronized and is not thread safe while HashTable is thread safe and is synchronized. HashMap allows one null key and values can be null whereas HashTable doesn't allow null key or value. HashMap is faster than HashTable. HashMap iterator is fail-safe where HashTable iterator is not fail-safe. HashMap extends AbstractMap class where HashTable extends Dictionary class.

Classes and objects are considered as the building blocks of object-oriented programming. Every entity with state and behavior is an object. Collection of these similar kinds of objects is a class. A class can be only accessed by its objects hence securing data in it. Read this article to learn more about objects and classes in Java and how they are different from each other. What are Classes in Java? A class is a user-defined data type that acts as a blueprint for designing the objects in it. It is said to be a container that stores objects of similar ... Read More

A command-line argument is an information that directly follows the program's name on the command line when it is executed. To access the command-line arguments inside a Java program is quite easy. They are stored as strings in the String array passed to main( ).ExampleThe following program displays all of the command-line arguments that it is called with -public class CommandLine {    public static void main(String args[]) {       for(int i = 0; i