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Class isAnnotationPresent() method in Java with Examples

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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-



Last Updated : 27 Dec, 2019
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