使用反射類、Class類獲取指定的構造器並實例化對象

package com.test;

public class Car {

    private String brand;
    private String color;
    private int maxSpeed;
    
    public Car(){}

    public Car(String brand, String color, int maxSpeed) {
        super();
        this.brand = brand;
        this.color = color;
        this.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;
    }

    @Override
    public String toString() {
        return "Car [brand=" + brand + ", color=" + color + ", maxSpeed="
                + maxSpeed + "]";
    }

}

package com.test;

import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
public class ReflectTest {

    public static Car initByDefaultConst() throws Throwable{
        //通過類轉載器獲取Car類對象
        //ClassLoader loader = Thread.currentThread().getContextClassLoader();
        //Class clazz = loader.loadClass("com.test.Car");
        Class clazz = Class.forName("com.test.Car");
        
        //構造器器參數列表
        Class[] cl = {String.class, String.class, int.class};
        
        //獲取默認的構造器
        //Constructor cons = clazz.getDeclaredConstructor(null);
        
        //獲取指定的帶參數的構造器對象，並通過它實例化Car
        Constructor cons = clazz.getDeclaredConstructor(cl);
        //構造器參數
        Object[] ps = {"紅旗H7", "黑色", 200};
        //創建實例
        Car car = (Car)cons.newInstance(ps);
        
        //通過反射方法設置屬性
/*        Method setBrand = clazz.getMethod("setBrand", String.class);
        setBrand.invoke(car, "紅旗H7");
        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();
        System.out.println(car);
    }

}