Class getDeclaredAnnotation() method in Java with Examples

The getDeclaredAnnotation() method of java.lang.Class class is used to get the declared annotation of the specified declared annotation type, if such an declared annotation is present in this class. The method returns that class in the form of an object.

Syntax:

public T getDeclaredAnnotation(Class<T> declared annotationClass)

Parameter: This method accepts a parameter declared annotationClass which is the type of the declared annotation to get.

Return Value: This method returns the specified object of the declared annotation class.

Exception: This method throws:

• NullPointerException: if the given declared annotation class is null.

Below programs demonstrate the getDeclaredAnnotation() method.

Example 1:

// Java program to demonstrate
// getDeclaredAnnotation() method

import java.util.*;
import java.lang.annotation.*;

// create a custom DeclaredAnnotation
@Retention(RetentionPolicy.RUNTIME)
@interface DeclaredAnnotation {

    // This declared annotation has two attributes.
    public String key();

    public String value();
}

// call DeclaredAnnotation for method
// and pass values for declared annotation
@DeclaredAnnotation(key = "GFG", value = "GeeksForGeeks")
public class Test {

    public Object obj;

    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 declared annotation
        // using getDeclaredAnnotation() method
        System.out.println(
            "DeclaredAnnotation of myClass: "
            + myClass
                  .getDeclaredAnnotation(
                      DeclaredAnnotation.class));
    }
}

Output:

Class represented by myClass: class Test
DeclaredAnnotation of myClass: @DeclaredAnnotation(key=GFG, value=GeeksForGeeks)

Example 2:

// Java program to demonstrate
// getDeclaredAnnotation() method

import java.util.*;
import java.lang.annotation.*;

@Deprecated
public class Test {

    public Object obj;

    public static void main(String[] args)
        throws ClassNotFoundException
    {
        try {
            // returns the Class object for this class
            Class myClass = Test.class;

            System.out.println(
                "Class represented by myClass: "
                + myClass.toString());

            // Get the declared annotation
            // using getDeclaredAnnotation() method
            System.out.println(
                "DeclaredAnnotation of myClass: "
                + myClass
                      .getDeclaredAnnotation(
                          Deprecated.class));
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}

Output:

Class represented by myClass: class Test
DeclaredAnnotation of myClass: @java.lang.Deprecated()

Reference: https://docs.oracle.com/javase/9/docs/api/java/lang/Class.html#getDeclaredAnnotation-java.lang.Class-