獲取字節(jié)碼的三種方式：

• Object類的getClass()方法
• 靜態(tài)屬性class
• Class類中的靜態(tài)方法forName()

接下來我們通過代碼實(shí)例來看看這三種方式以及通過字節(jié)碼創(chuàng)建對(duì)象
首先我們創(chuàng)建普通的Java項(xiàng)目
項(xiàng)目目錄結(jié)構(gòu)

Person.java

package com.wangc.reflect;

public class Person {
    
    String name;
    Integer age;
    public Person() {
        super();
    }
    public Person(String name, Integer age) {
        super();
        this.name = name;
        this.age = age;
    }
    
    public void show(){
        System.out.println("我是：" + name + "，年齡：" + age);
    }
}

Test.java

package com.wangc.reflect;

import java.lang.reflect.Constructor;

public class Test {
    
    public static void main(String[] args) throws Exception {
        //獲取字節(jié)碼的三種方式
        Class<?> clazz1 = Class.forName("com.wangc.reflect.Person");
        
        Class<Person> clazz2 = Person.class;
        
        Person person = new Person();
        Class<? extends Person> clazz3 = person.getClass();
        
        System.out.println(clazz1 == clazz2);
        System.out.println(clazz2 == clazz3);
        
        
        //有了字節(jié)碼之后就可以通過字節(jié)碼創(chuàng)建對(duì)象
        Person person2 = (Person) clazz1.newInstance();
        person2.name = "zhangsan";
        person2.age = 25;
        person2.show();
        
        //獲取構(gòu)造器
        Constructor<?> constructor = clazz1.getConstructor(String.class, Integer.class);
        //通過有參構(gòu)造器來創(chuàng)建對(duì)象
        Person person3 = (Person) constructor.newInstance("lisi", 28);
        person3.show();
    }
}

代碼運(yùn)行結(jié)果：

true
true
我是：zhangsan，年齡：25
我是：lisi，年齡：28