JAVA EE: Java Tutorial: Annotations in java | Java annotations [Built-In Annotations in Java

Thursday 11 May 2017

Java Tutorial: Annotations in java | Java annotations [Built-In Annotations in Java - @target]

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Java Tutorial: Annotations in java | Java annotations [Built-In Annotations in Java - @target]

HelloWorld.java

import java.lang.annotation.ElementType;
import java.lang.annotation.Target;

@Target({ElementType.TYPE, ElementType.FIELD, ElementType.METHOD})  
@interface MyAnnotation
    {
        int getValue() default 2;

        String getMessage() default "hello";

        double getDoubleValue() default 5.5;
    }


@MyAnnotation
public class HelloWorld
{
    @MyAnnotation
    private int value;
    
    @MyAnnotation
    public void displayHelloWorld()
    {
        System.out.println("Hello World");
    }
}

Message.java

import java.lang.annotation.ElementType;
import java.lang.annotation.Target;

@Target(ElementType.METHOD)
@interface MyMultiValueAnnotation
    {
        int getValue() default 2;

        String getMessage() default "hello";

        double getDoubleValue() default 5.5;
    }

public class Message
{
    @MyMultiValueAnnotation
    public void displayHi()
    {
        System.out.println("Hi");
    }
}