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() 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 ;
} |
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() 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 ;
} |
Output:
Value after applying setByte is 20