Package isAnnotationPresent() method in Java with Examples
Last Updated :
23 Aug, 2021
The isAnnotationPresent() method of java.lang.Package class is used to check if an annotation of the specified annotation type is present in this class. The method returns a boolean value starting 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 starting the same.
Exception: This method throws:
- NullPointerException: if the given annotation class is null.
Below programs demonstrate the isAnnotationPresent() method.
Example 1:
Java
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:
Java
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/Package.html#isAnnotationPresent-java.lang.Class-
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