利用java反射机制调用类的私有方法

1.将getInstance()方法设置为private

public class Singleton {
private static Singleton instance = null;
private static synchronized Singleton getInstance() {
System.out.println("调用 私有的单例!");
if (instance==null)
instance=new Singleton();

return instance;
}
}

2.使用反射机制调用getInstance()方法

import java.lang.reflect.Method;

public class test {

public static void main(String[] args) {

Class cl = null;
try{
cl=Singleton.class;
Method m1 =cl.getDeclaredMethod("getInstance");

m1.setAccessible(true);// 调用private方法的关键一句话
m1.invoke(cl);
}catch(Exception e){
e.printStackTrace();
}