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 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 )); } } |
AnnotatedElement represented by myAnnotatedElement: class Test
If there is any annotation in myAnnotatedElement: true
Example 2:
// 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 )); } } |
AnnotatedElement represented by myAnnotatedElement: class Test
If there is any annotation in myAnnotatedElement: false