Class getField() method in Java with Examples (original) (raw)

Last Updated : 16 Dec, 2019

The getField() method of java.lang.Class class is used to get the specified field of this class, which is the field that is public and its members. The method returns the specified field of this class in the form of Field objects.

Syntax:

public Field getField(String fieldName) throws NoSuchFieldException, SecurityException

Parameter: This method accepts a parameter fieldName which is the Field to get.

Return Value: This method returns the specified field of this class in the form of Field objects.

Exception This method throws:

• NoSuchFieldException if a field with the specified name is not found.
• NullPointerException if name is null
• SecurityException if a security manager is present and the security conditions are not met.

Below programs demonstrate the getField() method.

Example 1:

import java.util.*;

public class Test {

`` public Object obj;

`` public static void main(String[] args)

`` throws ClassNotFoundException, NoSuchFieldException

`` {

`` Class myClass = Class.forName( "Test" );

`` System.out.println( "Class represented by myClass: "

`` + myClass.toString());

`` String fieldName = "obj" ;

`` System.out.println(

`` fieldName + " Field of myClass: "

`` + myClass.getField(fieldName));

`` }

}

Output:

Class represented by myClass: class Test obj Field of myClass: public java.lang.Object Test.obj

Example 2:

import java.util.*;

class Main {

`` private Object obj;

`` Main()

`` {

`` class Arr {

`` };

`` obj = new Arr();

`` }

`` public static void main(String[] args)

`` throws ClassNotFoundException, NoSuchFieldException

`` {

`` Main t = new Main();

`` Class myClass = t.obj.getClass();

`` String fieldName = "obj" ;

`` try {

`` System.out.println(

`` fieldName + " Field of myClass: "

`` + myClass.getField(fieldName));

`` }

`` catch (Exception e) {

`` System.out.println(e);

`` }

`` }

}

Output:

java.lang.NoSuchFieldException: obj

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