setByte() method of java.lang.reflect.Field used to set the value of a field as a byte on the specified object. When you need to set the value of a field of an object as byte then you can use this method to set value over an Object.
Syntax:
public void setByte(Object obj, byte b) throws IllegalArgumentException, IllegalAccessException
Parameters: This method accepts accepts two parameters:
- obj: which is the object whose field should be modified and
- b: which is the new value for the field of obj being modified.
Return: This method returns nothing.
Exception: This method throws the following Exception:
- IllegalAccessException: if this Field object is enforcing Java language access control and the underlying field is either inaccessible or final.
- IllegalArgumentException: if the specified object is not an instance of the class or interface declaring the underlying field (or a subclass or implementor thereof), or if an unwrapping conversion fails.
- NullPointerException: if the specified object is null and the field is an instance field.
- ExceptionInInitializerError: if the initialization provoked by this method fails.
Below programs illustrate setByte() method:
Program 1:
// Java program to illustrate setByte() method import java.lang.reflect.Field; public class GFG { public static void main(String[] args) throws Exception { // create user object Employee emp = new Employee(); // print value of leaveLeft System.out.println( "Value of leaveLeft before " + "applying setByte is " + emp.leaveLeft); // Get the marks field object Field field = Employee. class .getField( "leaveLeft" ); // Apply setByte Method field.setByte(emp, ( byte ) 2 ); // print value of leaveLeft System.out.println( "Value of leaveLeft after " + "applying setByte is " + emp.leaveLeft); // print value of age System.out.println( "Value of age before " + "applying setByte is " + emp.age); // Get the marks field object field = Employee. class .getField( "age" ); // Apply setByte Method field.setByte(emp, ( byte ) 56 ); // print value of age System.out.println( "Value of age after " + "applying setByte is " + emp.age); } } // sample class class Employee { // static byte values public static byte age = 45 ; public static byte leaveLeft = 12 ; } |
Value of leaveLeft before applying setByte is 12 Value of leaveLeft after applying setByte is 2 Value of age before applying setByte is 45 Value of age after applying setByte is 56
Program 2:
// Java program to illustrate setByte() method import java.lang.reflect.Field; public class GFG { public static void main(String[] args) throws Exception { // create user object User user = new User(); // Get the id field object Field field = User. class .getField( "id" ); // Apply setByte Method field.setByte(user, ( byte ) 20 ); // print value of isActive System.out.println( "Value after " + "applying setByte is " + user.id); } } // sample User class class User { // static byte values public static byte id = 2 ; } |
Value after applying setByte is 20
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