2.Sprng-IoC-Java反射例子

1.Car.java

package com.jike.spring.chapter03.reflect;

public class Car {
    private String brand;

    private String color;

    private int maxSpeed;

    //1.默认构造函数
    public Car(){
        System.out.println("init car!!");
        }
    
    //2.带参构造函数
    public Car(String brand,String color,int maxSpeed){
        this.brand = brand;
        this.color = color;
        this.maxSpeed = maxSpeed;
    }
    
    //3.未带参的方法
    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;
    }
}

2.ReflectTest.java

package com.jike.spring.chapter03.reflect;

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


public class ReflectTest {
  

    public static Car  initByDefaultConst() throws Throwable
    {
        //1.通过类装载器获取Car类对象
        ClassLoader loader = Thread.currentThread().getContextClassLoader();        
        Class clazz = loader.loadClass("com.jike.spring.chapter03.reflect.Car");
    
        //2.获取类的默认构造器对象并实例化Car
        Constructor cons = clazz.getDeclaredConstructor((Class[])null);
        Car car = (Car)cons.newInstance();
        
        //3.通过反射方法设置属性
        Method setBrand = clazz.getMethod("setBrand",String.class);        
        setBrand.invoke(car,"奔驰");        
        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 Car initByParamConst()  throws Throwable{
        //1.通过类装载器获取Car类对象
        ClassLoader loader = Thread.currentThread().getContextClassLoader();
        Class clazz = loader.loadClass("com.jike.spring.chapter03.reflect.Car");
        
        //2.获取类的带有参数的构造器对象
        Constructor cons = clazz.getDeclaredConstructor(new Class[]{String.class,String.class,int.class});
        
        //3.使参数的构造器对象实例化Car
        Car car = (Car)cons.newInstance(new Object[]{"宝马","红色",180});
        return car;    
    }
    
    public static void main(String[] args) throws Throwable {
        Car car1 = initByDefaultConst();
        Car car2 = initByParamConst();
        car1.introduce();
        car2.introduce();
    }
}