反射概述

获得反射对象

package com.test5;
//什么叫反射
public class test1 {
public static void main(String[] args) throws ClassNotFoundException {
	//通过反射获取类的class对象
	Class c1=Class.forName("com.test5.User");
	System.out.println(c1);        //class com.test5.User
	Class c2=Class.forName("com.test5.User");
	Class c3=Class.forName("com.test5.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());   //925858445
	System.out.println(c3.hashCode());   //925858445
	
}
}
//实体类: pojo ,entity
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 + "]";
	}
	
}

Class类