What are Annotations in Java ?.
Annotations in Java are metadatas that adds information to your code in a formal way so that you can keep track to the information added at a later stage. They provide a Java programmer information which describes the program fully in a sophisticated way. Annotations help us in generating descriptor files and giving us way to write boilerplate code each time.
Annonations in Java have a symbol @ in its syntax declaration. Java contains general purpose built in annotations defined in java.lang package as :
@Deprecated : Generally, it gives a programmer a compiler warning if he wishes to use a thing which is marked as Deprecated.
Program to demonstrate how to deprecate methods in Java
package com.hubberspot.example;
public class DeprecateTest {
// One way do deprecate is to use
// @Deprecated annotation
@Deprecated
public void draw() {
System.out.println("Deprecated by @Deprecated annotation");
}
/**
* @deprecated
*
*/
public void area() {
System.out.println("Deprecated by @deprecated javadoc tag");
}
public static void main(String[] args) {
DeprecateTest test = new DeprecateTest();
// It might be unavailable in next release
// say method is inefficient, having bugs,
// insecure in implementation and may result
// in bad coding practices
test.draw();
test.area();
}
}
Output of the program :
