AnnotatedElement isAnnotationPresent() method in Java with Examples

The isAnnotationPresent() method of java.lang.AnnotatedElement class is used to check if an annotation of the specified annotation type is present in the class implementing this interface. The method returns a boolean value stating 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 stating 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.reflect.*;
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 myAnnotatedElement
        AnnotatedElement myAnnotatedElement
            = Test.class;

        System.out.println(
            "AnnotatedElement represented"
            + " by myAnnotatedElement: "
            + myAnnotatedElement.toString());

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

Output:

AnnotatedElement represented by myAnnotatedElement: class Test If there is any annotation in myAnnotatedElement: true

Example 2:

Java

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

import java.util.*;
import java.lang.reflect.*;
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 myAnnotatedElement
        AnnotatedElement myAnnotatedElement
            = Test.class;

        System.out.println(
            "AnnotatedElement represented"
            + " by myAnnotatedElement: "
            + myAnnotatedElement.toString());

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

Output:

AnnotatedElement represented by myAnnotatedElement: class Test If there is any annotation in myAnnotatedElement: false

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

AnnotatedElement isAnnotationPresent() method in Java with Examples

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