先定義一個JavaBean

package com.jim.test.Test;

public class User {
    private int id;
    private String name = "abc";
    private String password = "12345";

    public int getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return
 
 name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    private void privateMethod() {
        System.out.println("access the private method"
 
);
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

1. 通過類名生成物件

@Test
    public void testCreateObjectByClassName() throws
 
 ClassNotFoundException, InstantiationException, IllegalAccessException {
        Class<?> clazz = Class.forName("com.jim.test.Test.User");
        User user = (User) clazz.newInstance();
        System.out.println(user);
    }

1. 訪問私有方法

@Test
    public void testAccessPrivateMethod() throws Exception {
        Class<?> clazz = Class.forName("com.jim.test.Test.User");

        Method method = clazz.getDeclaredMethod("privateMethod", null);
        method.setAccessible(true);
        method.invoke(clazz.newInstance(), null);
    }