Package isAnnotationPresent() method in Java with Examples

Last Updated : 23 Aug, 2021

The isAnnotationPresent() method of java.lang.Package class is used to check if an annotation of the specified annotation type is present in this class. The method returns a boolean value starting the same.

Syntax:

public boolean isAnnotationPresent(Class<T> annotationClass)

Parameter: This method accepts a parameter annotationClass which is the type of the annotation to get.
Return Value: This method returns boolean value starting the same.
Exception: This method throws:

NullPointerException: if the given annotation class is null.

Below programs demonstrate the isAnnotationPresent() method.
Example 1:

Java

// Java program to demonstrate
// isAnnotationPresent() method

import java.util.*;
import java.lang.annotation.*;

// create a custom Annotation
@Retention(RetentionPolicy.RUNTIME)
@interface Annotation {

    // This annotation has two attributes.
    public String key();

    public String value();
}

// call Annotation for method
// and pass values for annotation
@Annotation(key = "GFG", value = "GeeksForGeeks")
public class Test {

    public static void main(String[] args)
        throws ClassNotFoundException
    {

        // returns the Class object for this class
        Class myClass = Test.class;

        System.out.println("Class represented by myClass: "
                           + myClass.toString());

        // Check if there is any annotation
        // using isAnnotationPresent() method
        System.out.println(
            "If there is any annotation in myClass: "
            + myClass.isAnnotationPresent(
                  Annotation.class));
    }
}

Output:

Class represented by myClass: class Test
If there is any annotation in myClass: true

Example 2:

Java

// Java program to demonstrate
// isAnnotationPresent() method

import java.util.*;
import java.lang.annotation.*;

// Class with no annotations
public class Test {

    public static void main(String[] args)
        throws ClassNotFoundException
    {

        // returns the Class object for this class
        Class myClass = Test.class;

        System.out.println("Class represented by myClass: "
                           + myClass.toString());

        // Get the annotation
        // using isAnnotationPresent() method
        System.out.println(
            "If there is any annotation in myClass: "
            + myClass.isAnnotationPresent(
                  Annotation.class));
    }
}