获得反射对象

package edu.wtbu;
//反射
public class Demo03 extends Object{
    public static void main(String[] args) throws ClassNotFoundException {
        User user = new User();
        Class<? extends User> aClass = user.getClass();//返回指定类名的class对象
        System.out.println(aClass);//class edu.wtbu.User

        Class<?> c1 = Class.forName("edu.wtbu.User");
        System.out.println(c1);//class edu.wtbu.User
        Class<?> c2 = Class.forName("edu.wtbu.User");//返回指定类名的class对象
        Class<?> c3 = Class.forName("edu.wtbu.User");
        Class<?> c4 = Class.forName("edu.wtbu.User");
        //一个类在内存中只有一个class对象
        //一个类被加载后，类的整个结构都会被封装在class对象中
        System.out.println(c2.hashCode());
        System.out.println(c3.hashCode());
        System.out.println(c4.hashCode());

    }
}
//实体类：pojo或者entity表示
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 +
                '}';
    }
}