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 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 implementer 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
// Java program to illustrate setByte() methodimport 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 classclass Employee { // static byte values public static byte age = 45; public static byte leaveLeft = 12;} |
Output:
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
// Java program to illustrate setByte() methodimport 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 classclass User { // static byte values public static byte id = 2;} |
Output:
Value after applying setByte is 20
