Class getAnnotationsByType() method in Java with Examples (original) (raw)

Last Updated : 27 Dec, 2019

The getAnnotationsByType() method of java.lang.Class class is used to get the annotations of the specified annotation type present in this class. The method returns an array of annotations for the specified annotation type.

Syntax:

public A[] getAnnotationsByType(Class annotationClass)

Parameter: This method accepts a parameter annotationClass which is the type of the annotation to get.

Return Value: This method returns an array of annotations for the specified annotation type.

Exception: This method throws:

• NullPointerException: if the given annotation class is null.

Below programs demonstrate the getAnnotationsByType() method.

Example 1:

import java.util.*;

import java.lang.annotation.*;

@Retention (RetentionPolicy.RUNTIME)

@interface Annotation {

`` public String key();

`` public String value();

}

@Annotation (key = "GFG" , value = "GeeksForGeeks" )

public class Test {

`` public Object obj;

`` public static void main(String[] args)

`` throws ClassNotFoundException

`` {

`` Class myClass = Test. class ;

`` System.out.println(

`` "Class represented by myClass: "

`` + myClass.toString());

`` System.out.println(

`` "Annotation of myClass of type Annotation: "

`` + Arrays.toString(

`` myClass

`` .getAnnotationsByType(

`` Annotation. class )));

`` }

}

Output:

Class represented by myClass: class Test Annotation of myClass of type Annotation: [@Annotation(key=GFG, value=GeeksForGeeks)]

Example 2:

import java.util.*;

import java.lang.annotation.*;

@Deprecated

public class Test {

`` public Object obj;

`` public static void main(String[] args)

`` throws ClassNotFoundException

`` {

`` try {

`` Class myClass = Test. class ;

`` System.out.println(

`` "Class represented by myClass: "

`` + myClass.toString());

`` System.out.println(

`` "Annotation of myClass of type Deprecated: "

`` + Arrays.toString(

`` myClass

`` .getAnnotationsByType(

`` Deprecated. class )));

`` }

`` catch (Exception e) {

`` System.out.println(e);

`` }

`` }

}

Output:

Class represented by myClass: class Test Annotation of myClass of type Deprecated: [@java.lang.Deprecated()]

Reference: https://docs.oracle.com/javase/9/docs/api/java/lang/Class.html#getAnnotationsByType-java.lang.Class-