how to call private method from another class in java.

We can call the private method of a class from another class in Java using Reflection API.

  • getDeclaredMethod return a method that reflect to specify in class and represent by Class object.
  • invoke() method call the type of object and pass the parameter  when we want to invoke.
  • demo() method name we want to call from getDeclaredMethod.
  • Class[] declare the parameters that method take when we want to execute.

Syntax :-  public void setAccessible(boolean status) throws Exception

                 public Object invoke(Object method, Object… args) throws IllegalAccessException

				
					import java.lang.reflect.Method;

class Hello {
	private void demo(String str) {
		System.out.println("welcome to java " + str);
	}
}

public class PrivateMethodTest {
	public static void main(String[] args) throws Exception {

		Class c = Hello.class;
		Object p = c.newInstance();

		Method m = c.getDeclaredMethod("demo", new Class[] { String.class });
		m.setAccessible(true);
		m.invoke(p, "collection");
	}
}

Output :-
welcome to java collection