利用反射读取类的私有变量

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获取Class对象方法的三种方式：

类名.class;
对象名.getClass();
Class.forName("类"); " com.wsq.UserBean"

public class A {
private String rubbish="1111";
public String rubbish1="2222";
}

import java.lang.reflect.Field;

public class B {

public static void main(String[] args) throws InstantiationException, IllegalAccessException, SecurityException, NoSuchFieldException {
       Class clazz=A.class;
        Field field=clazz.getDeclaredField("rubbish");              // 要是私有要用这个方法

     Field field1=clazz.getDeclaredField("rubbish1");

     Field field2=clazz.getField("rubbish1");       //只能访问public

     field.setAccessible(true);//改变可访问权限

     A obj=(A)clazz.newInstance();

      System.out.println("私有"+field.get((obj)));
        System.out.println("公有"+field1.get((obj)));
        System.out.println(“公有"+field2.get((obj)));
  }