Class getAnnotation() method in Java with Examples
Last Updated :
27 Dec, 2019
The getAnnotation() method of java.lang.Class class is used to get the annotation of the specified annotation type, if such an annotation is present in this class. The method returns that class in the form of an object.
Syntax:
public T getAnnotation(Class<T> annotationClass)
Parameter: This method accepts a parameter annotationClass which is the type of the annotation to get.
Return Value: This method returns the specified object of the annotation class.
Exception: This method throws:
- NullPointerException: if the given annotation class is null.
Below programs demonstrate the getAnnotation() 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(
"Annotation of myClass: "
+ myClass.getAnnotation(
Annotation. class ));
}
}
|
Output:
Class represented by myClass: class Test
Annotation of myClass: @Annotation(key=GFG, value=GeeksForGeeks)
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(
"Annotation of myClass: "
+ myClass.getAnnotation(
Annotation. class ));
}
}
|
Output:
Class represented by myClass: class Test
Annotation of myClass: null
Reference: https://docs.oracle.com/javase/9/docs/api/java/lang/Class.html#getAnnotation-java.lang.Class-
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