Class isAnnotationPresent() method in Java with Examples

Last Updated : 27 Dec, 2019

The isAnnotationPresent() method of java.lang.Class class is used to check if an annotation of the specified annotation type is present in this class. 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 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 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)); 
    } 
} 

Output:

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

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

Package isAnnotationPresent() method in Java with Examples

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Class isAnnotationPresent() method in Java with Examples

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