java学习day15---UDP,reflect,proxy

 public class Client {
    @SuppressWarnings("resource")
    public static void main(String[] args) throws Exception {
    //Socket 对象
    while(true) {
    byte[] b = "看海".getBytes();
    DatagramSocket ds = new DatagramSocket();
    InetAddress address = InetAddress.getLocalHost();
    DatagramPacket pa = new DatagramPacket(b, b.length, address, 8090);
    ds.send(pa);

    ds.close();
    }
    }
}

public class Server {

    @SuppressWarnings("resource")
    public static void main(String[] args) throws Exception {
    // TODO Auto-generated method stub
    DatagramSocket ds = new DatagramSocket(8090);
    while(true) {
    byte[] b = new byte[64*1024];
    DatagramPacket p = new DatagramPacket(b, b.length);

    //接收数据
    ds.receive(p);
    byte[] data = p.getData();
    int l = p.getLength();
    System.out.println(new String(data,0,l));
    ds.close();
    }

    }

}

  //获取User类的Class对象
    //一  通过对象 getClass()f方法
    User user = new User();
    Class<? extends User> c1 = user.getClass();
    //方式二  通过类
    Class<User>  c2 = User.class;
    //方法三  通过字符串
    Class<?> c3 = Class.forName("day14.reflect.User");
    System.out.println(c3.getName());

  //获取所有方法
    Method[] methods = c1.getMethods();
  //获取本类中的方法
    Method[] methods2 = c1.getDeclaredMethods();

  //获取公共的属性
    Field[] fields = c.getFields();
  //获取所有属性
    Field[] fields2 = c.getDeclaredFields();
  //获取所有构造函数
   Constructor<?>[] ct = c4.getConstructors();

   //获取某一个构造函数，并且创建对象  
   Constructor<?> con = c4.getConstructor(int.class,String.class);  //获取某一个构造函数
    Object user = con.newInstance(12,"haha");

    //强制修改私有变量
     Field f2 = c.getDeclaredField("name");     
        f2.setAccessible(true);
        f2.set(user, "刘惜君");
    //某个具体的方法
    Method m1 = c.getDeclaredMethod("run", String.class);
        m1.setAccessible(true);
        m1.invoke(user, "刘惜君我爱你");

 public  void add() {
    System.out.println("开始购买。。。");
    super.add();

}

   public class MyProxy extends UserServiceImpl{
    UserService impl;
    public MyProxy() {

    }
    //构造函数 传递父类
    public MyProxy(UserService impl) {
        this.impl=impl;
    }
    public  void run() {
        System.out.println("开始事务。。。");
        impl.add();
    }
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        UserService us = new UserServiceImpl();
        MyProxy m = new MyProxy(us); 
        m.run();
    }

}

 public class TestProxy {

public static void main(String[] args) {
    // TODO Auto-generated method stub
        /**
     * 第一个参数  类加载器  加载本项目中的所有类的的字节码
     * 第二个参数  获取被代理的对象的所有方法
     * 参数三         告诉他你的代理的业务，用来进行增强事务
     */
    UserService object = (UserService) Proxy.newProxyInstance(TestProxy.class.getClassLoader(), (Class<?>[]) UserServiceImpl.class.getGenericInterfaces(), new InvocationHandler() {

        @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("开启事务");
 Object invoke = method.invoke(new UserServiceImpl(), args);
        System.out.println("结束事务");
         return null;
            }
        });
        object.sub();
    }

}

  Properties p =new Properties();
    p.load(new FileInputStream("conf/bean.properties"));
    String className = p.getProperty("classname");
   Reader r = (Reader)Class.forName(className).newInstance();//创建实例对象
    r.read();
  配置文件(bean.properties):
  classname=day14.test.ReaderFile