public class Car {
    private String brand;
    private String color;
    private int maxSpeed;

    public Car() {
    }

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

    public void introduce() {
        System.out.println("brand:"+brand+";color:"+color+";maxspeed:"+maxSpeed);
    }
}

//通过类加载器加载Car类对象
ClassLoader loader = Thread.currentThread().getContextClassLoader();
Class<?> clazz = loader.loadClass("com.example.demo.Test.Car");

//获取类的默认构造器并通过它实例化Car
Constructor cons = clazz.getDeclaredConstructor((Class[]) null);
Car car = (Car) cons.newInstance();


//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;

java反射机制-简单实例