动态代理--（未完）

 

public interface IUserService {
 public void addUser(String name, String password);
 public void deleteUser(int id);
}

public class UserService implements IUserService {
 public void addUser(String name, String password) {
  System.out.println("--------adduser--------");
 }
 public void deleteUser(int id) {
  System.out.println("--------deleteUser--------");
 }
}
具体实现
public class AuthHandler implements InvocationHandler {
 IUserService userService;
 public AuthHandler(IUserService userService) {
  super();
  this.userService = userService;
 }
 public Object invoke(Object obj, Method method, Object[] args)
   throws Throwable {
  //do other thing
  method.invoke(userService, args);
  //do other thing
  return null;
 }
}
如果改成通用代理，只要将具体类改为object类即可

客户端调用

import java.lang.reflect.Proxy;
public class TestClient {
 public static void main(String[] args) {
  IUserService userService=new UserService();
  AuthHandler authHandler=new AuthHandler(userService);
  IUserService userServiceproxy=(IUserService)Proxy.newProxyInstance(userService.getClass().getClassLoader(), userService.getClass().getInterfaces(), authHandler);
  userServiceproxy.addUser("name", "password");
 }
}

 

 

 

 

 

 

 

 

 

 

动态代理和静态代理一样首先也要满足三个条件

1、一个含有抽象方法的接口或者抽象类

public interface IPermissionService {
 public void getPermissions(String name);
}

2、实现抽象方法的实际类

public class PermissionService implements IPermissionService {
 public void getPermissions(String name) {
  System.out.println("getPermissions");
 }
}

 

3、动态代理类

public class DynamicHandler implements InvocationHandler {
 public Object obj = null;

 public DynamicHandler(Object obj) {

  this.obj = obj;
 }

 public Object createObject() {

  Object o = Proxy.newProxyInstance(obj.getClass()
    .getClassLoader(),
    obj.getClass().getInterfaces(), this);

  return  o;
 }

 public Object invoke(Object proxy, Method method, Object[] args) {// throws
  // Throwable
  ThreadContext.setConnection();

  Object o = null;
  try {
   o = method.invoke(obj, args);
  } catch (IllegalArgumentException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (IllegalAccessException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (InvocationTargetException e) {
   Throwable t = e.getTargetException();
   e.printStackTrace();
   Connection conn = ThreadContext.getConnection();
   DB.rollback(conn);
   throw (AppRuntimeException) t;

  } finally {
   Connection conn = ThreadContext.getConnection();
   DB.commit(conn);
   ThreadContext.close(conn);
  }
  return o;
 }

}

调用实现

 

import java.lang.reflect.Proxy;

public class Test {

 public static void main(String[] args) {
  IPermissionService permissionService = new PermissionService();
  DynamicHandler handler = new DynamicHandler(permissionService);
IPermissionService pm = (IPermissionService)Proxy.newProxyInstance(permissionService.getClass().getClassLoader(),permissionService.getClass().getInterfaces(), handler);
  pm.getPermissions("");
 }

}