package com.smart.reflect;public class Car {private String brand;private String color;private int maxSpeed;//默认构造函数public Car(){}//带参构造函数public Car(String brand, String color, int maxSpeed) {this.brand = brand;this.color = color;this.maxSpeed = maxSpeed;}//未带参方法public void introduce() {System.out.println("brand:" + brand + ";color:" + color + ";maxSpeed:" + maxSpeed);}public String getBrand() {return brand;}public void setBrand(String brand) {this.brand = brand;}public String getColor() {return color;}public void setColor(String color) {this.color = color;}public int getMaxSpeed() {return maxSpeed;}public void setMaxSpeed(int maxSpeed) {this.maxSpeed = maxSpeed;}
}

package com.smart.reflect;import sun.reflect.CallerSensitive;import java.lang.reflect.Constructor;
import java.lang.reflect.Method;public class ReflectTest {public static Car initByDefaultConst() throws Throwable {/*类装载器工作机制：(1)装载：查找和导入Class文件(2)链接：1.校验：检查载入Class文件数据的正确性2.准备：给类的静态变量分配存储空间3.解析：将符号引用转化为直接引用（可选）(3)初始化：对类的静态变量、静态代码块执行初始化工作*/// 1. 通过类加载器获取Car类对象ClassLoader loader = Thread.currentThread().getContextClassLoader();Class clazz = loader.loadClass("com.smart.reflect.Car");// 2. 获取类的默认构造器对象并通过它实例化CarConstructor constructor = clazz.getConstructor((Class[]) null);Car car = (Car) constructor.newInstance();// 3. 通过反射方法设置属性Method setBrand = clazz.getMethod("setBrand", String.class);setBrand.invoke(car, "红旗CA72");Method setColor = clazz.getMethod("setColor", String.class);setColor.invoke(car, "黑色");Method setMaxSpeed = clazz.getMethod("setMaxSpeed", int.class);setMaxSpeed.invoke(car, 200);return car;}public static void main(String[] args) throws Throwable {Car car = initByDefaultConst();car.introduce();//JVM装载类时使用“全盘负责委托机制”// 1.当一个ClassLoader装载一个类时，除非显式的使用另一个ClassLoader,该类所依赖及引用的类也由这个ClassLoader载入// 2.先委托父类装载器寻找目标类，只有在找不到的情况下才从自己的类路径中查找并装载目标类
    }
}