Class isAnnotationPresent() method in Java with Examples
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:
import java.util.*;
import java.lang.annotation.*;
@Retention (RetentionPolicy.RUNTIME)
@interface Annotation {
public String key();
public String value();
}
@Annotation (key = "GFG" , value = "GeeksForGeeks" )
public class Test {
public static void main(String[] args)
throws ClassNotFoundException
{
Class myClass = Test. class ;
System.out.println( "Class represented by myClass: "
+ myClass.toString());
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:
import java.util.*;
import java.lang.annotation.*;
public class Test {
public static void main(String[] args)
throws ClassNotFoundException
{
Class myClass = Test. class ;
System.out.println( "Class represented by myClass: "
+ myClass.toString());
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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