2011/12/5

原來spring中用到了java的反射機制，研究了下java的反射機制發現靜态代理中的method.invoke(sub, args);也是用動态代理實作的。

将用反射機制執行個體化的類：

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 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;
	}
	

}
           

反射機制的代碼：

public class ReflectTest {

	/**
	 * @param args
	 * @throws NoSuchMethodException
	 * @throws SecurityException
	 */

	public static Car initByDefaultConst() throws Exception {
		ClassLoader loader = Thread.currentThread().getContextClassLoader();
		Class clazz = loader.loadClass("org.model.Car");

		Constructor cons = clazz.getDeclaredConstructor(null);//擷取構造函數
		Car car = (Car) cons.newInstance();   執行個體化

		Method setBrand = clazz.getMethod("setBrand", String.class); //擷取類中方法
		setBrand.invoke(car, "CA72");調用方法

		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;
	}

	@SuppressWarnings("unchecked")
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		try {
			Car car = ReflectTest.initByDefaultConst();
			car.introduce();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

	}

}