Method Class | getAnnotatedReturnType() method in Java

The java.lang.reflect.Method.getAnnotatedReturnType() method returns an AnnotatedType object which represents AnnotatedType to specify return type of Method Object. If Method object is created for a constructor, then AnnotatedType object specifies the type of the constructed object. If Method object is created for a method, the AnnotatedType object specifies the use of a type to specify the return type of the method specified in the source code.

The returned AnnotatedType represents implementation of AnnotatedType itself or any of its sub-interfaces like AnnotatedArrayType, AnnotatedParameterizedType, AnnotatedTypeVariable, AnnotatedWildcardType. AnnotatedType represents the potentially annotated use of any type including an array type, a parameterized type, a type variable, or a wildcard type currently running in Java Virtual Machine.

Syntax:

public AnnotatedType getAnnotatedReturnType()

Return Value: This method returns an AnnotatedType object which represents AnnotatedType to specify return type of Method Object.

Below programs illustrates getAnnotatedReturnType() method of Method class:

Example 1:Use AnnotatedType() for a specific method given as Input.

The program contains a Method name getAddressMethod which contains AnnotatedType. So this program is going to get details of AnnotatedType, contained by getAddressMethod Method.

// Java program to demonstrate how to
// apply getAnnotatedReturnType() method
// of Method Class.

import java.lang.annotation.*;
import java.lang.reflect.AnnotatedType;
import java.lang.reflect.Method;
import java.util.Arrays;

public class GFG {

    // Creating custom AnnotatedType
    @Target({ ElementType.TYPE_USE })
    @Retention(RetentionPolicy.RUNTIME)
    private @interface customAnnotatedType {
    }

    // a sample method with return type String and
    // AnnotatedType is @customAnnotatedType
    public @customAnnotatedType String getAddress()
    {
        return null;
    }

    // main method
    public static void main(String[] args)
    {

        try {
            // create class object
            Class classobj = GFG.class;

            // create method object of getAddress
            Method getAddressMethod = null;

            Method[] methods = classobj.getMethods();
            for (Method m : methods) {
                if (m.getName().equals("getAddress"))
                    getAddressMethod = m;
            }

            // get AnnotatedType for return type
            AnnotatedType annotatedType = getAddressMethod
                                              .getAnnotatedReturnType();

            // print AnnotatedType details with Method name
            System.out.println("Method Name: "
                               + getAddressMethod.getName());

            System.out.println("Type: "
                               + annotatedType.getType().getTypeName());

            System.out.println("Annotations: "
                               + Arrays.toString(annotatedType.getAnnotations()));
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Output:

Method Name: getAddress
Type: java.lang.String
Annotations: [@GFG$customAnnotatedType()]

Example 2: To print Annotation on array type or multidimensional array or Generic for Methods of class GFG.

// Java program to demonstrate how to
// apply getAnnotatedReturnType() method
// of Method Class.

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

public class systemUTCMethodDemo<T> {

    // Creating custom AnnotatedType
    @Target({ ElementType.TYPE_USE })
    @Retention(RetentionPolicy.RUNTIME)
    private @interface customAnnotatedType {
    }

    // a sample method with Annotation on array type
    public @customAnnotatedType String[] getAddress()
    {
        return null;
    }

    // a sample method on Annotation on multidimensional array
    public String[] @customAnnotatedType[] getvalues()
    {
        return null;
    }

    // a sample method on Annotation on a type with generic
    public @customAnnotatedType List<T> getWords()
    {
        return null;
    }

    // main method
    public static void main(String[] args)
    {

        try {
            // create class object
            Class classobj = systemUTCMethodDemo.class;

            // create method object of getAddress and getValues
            Method[] methods = classobj.getMethods();

            for (Method m : methods) {

                // if method object is for getAddress and getValues
                // then print @customAnnotatedType for both
                if (m.getName().equals("getAddress")
                    || m.getName().equals("getvalues")
                    || m.getName().equals("getWords")) {
                    printDetails(m);
                }
            }
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void printDetails(Method m)
    {

        // get AnnotatedType for return type
        AnnotatedType annotatedType = m.getAnnotatedReturnType();

        // print AnnotatedType details with Method name

        System.out.println("Method Name: " + m.getName());
        System.out.println("Type: " + annotatedType.getType().getTypeName());
        System.out.println("Annotations: " + annotatedType);
        System.out.println();
    }
}

Output:

Method Name: getWords
Type: java.util.List
Annotations: sun.reflect.annotation.AnnotatedTypeFactory$AnnotatedParameterizedTypeImpl@12a3a380

Method Name: getvalues
Type: java.lang.String[][]
Annotations: sun.reflect.annotation.AnnotatedTypeFactory$AnnotatedArrayTypeImpl@29453f44

Method Name: getAddress
Type: java.lang.String[]
Annotations: sun.reflect.annotation.AnnotatedTypeFactory$AnnotatedArrayTypeImpl@5cad8086

Reference: https://docs.oracle.com/javase/8/docs/api/java/lang/reflect/AnnotatedType.html