import org.junit.Test;

import java.lang.reflect.Field;

import java.lang.reflect.Method;

public class ExplorePrivateTest {

private String privateMsg = "Original";

private void privateMethod(String head, int tail){

System.out.println(head + " " + tail);

}

public String getMsg(){

return privateMsg;

}

private void getPrivateMethod() throws Exception{

ExplorePrivateTest ept = new ExplorePrivateTest();

Class clazz = ept.getClass();

Method privateMethod = clazz.getDeclaredMethod("privateMethod", String.class, int.class);

if(privateMethod != null){

privateMethod.setAccessible(true);

privateMethod.invoke(ept, "java reflect", 666);

}

}

@Test

public void test() throws Exception {

getPrivateMethod();

}

private void modifyPrivateField() throws NoSuchFieldException, IllegalAccessException {

ExplorePrivateTest ept = new ExplorePrivateTest();

Class clazz = ept.getClass();

Field privateField = clazz.getDeclaredField("privateMsg");

if(privateField != null){

privateField.setAccessible(true);

System.out.println("Before modified: " + ept.getMsg());

privateField.set(ept, "Modified");

System.out.println("After modified: " + ept.getMsg());

}

}

@Test

public void test2() throws NoSuchFieldException, IllegalAccessException {

modifyPrivateField();

}

}