java反射调用方法时，Class . can not access a member of class . with modifiers "private" 等异常解决

先看javabean类：目的使用反射调用私有方法：

package com.imooc.reflect;

public class Student {

    private void add(){
        System.out.println("增加数据！");
    }

    private int id;
    private String name;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }

    public Student(int id, String name) {
        super();
        this.id = id;
        this.name = name;
    }
    public Student() {

    }
}

main测试方法

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

        Class c1=Student.class;
        Object obj=(Object)c1.newInstance();

        Method  add = c1.getDeclaredMethod("add");
        add.invoke((Student)obj);
    }

这时，就会报Class . can not access a member of class . with modifiers “private” 异常。
解决方案：添加一行代码：add.setAccessible(true);

Method  add = c1.getDeclaredMethod("add");
add.setAccessible(true);
add.invoke((Student)obj);

当然最后调用时也可以写成：add.invoke(obj);