有了class对象，能干什么

package top.ltyzqhh.Reflection;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;

//动态创建对象，通过反射
public class Test08 {
    public static void main(String[] args) throws Exception {
        //获得class对象
        Class<?> c1 = Class.forName("top.ltyzqhh.Reflection.User");

        //构造一个对象
        User user = (User) c1.getDeclaredConstructor().newInstance();//本质是调用了类的无参构造器
         System.out.println(user);

        //通过构造器创建对象
         Constructor constructor = c1.getDeclaredConstructor(String.class, int.class, int.class);
        User user2 = (User) constructor.newInstance("小明", 001, 18);
        System.out.println(user2);

        //通过反射调用普通方法
        User user3 = (User) c1.getDeclaredConstructor().newInstance();
        //通过反射获取一个方法
        Method setName = c1.getDeclaredMethod("setName", String.class);

        //invoke :激活的意思
        //(对象，“方法的值”)
        setName.invoke(user3,"haha");
        System.out.println(user3.getName());
        System.out.println("========================");

        //通过反射操作属性
        User user4 = (User) c1.getDeclaredConstructor().newInstance();
        Field name = c1.getDeclaredField("name");

        //不能直接操作私有属性，我们需要设置可访问性，属性或者方法的setAccessible(true)
        name.setAccessible(true);//设置private可以访问（取消安全检测）
        name.set(user4,"yahaha");
        System.out.println(user4.getName());
    }
}

运行结果

附件：User类

class User{

    private String name;
    private int id;
    private int age;

    public User(){
    }

    public User(String name,int id,int age){
        this.name=name;
        this.id=id;
        this.age=age;
    }

    public String getName() {
        return name;
    }

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

    public int getId() {
        return id;
    }

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

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

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