设计模式之动态代理

动态代理具体的实现过程，我估计里面就是用的反射，让我自己写大概也行，但是肯定写的不如人家好，但是必要的参数已经传进去了，所以能写个大概。

• Teacher

  • public interface Teacher {
        public void teach();
    }
    

• TeacherDao

  • public class TeacherDao implements Teacher{
        @Override
        public void teach() {
            System.out.println("老师正在授课");
        }
    }
    

• ProxyFactory

  • public class ProxyFactory {
        private Object targer;
    
        public ProxyFactory(Object targer){
            this.targer = targer;
        }
    
        public Object getProxyInstance(){
            return Proxy.newProxyInstance(targer.getClass().getClassLoader(),
                    targer.getClass().getInterfaces(), 
                    new InvocationHandler() {
                        @Override
                        public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                            System.out.println("jdk代理开始");
                            Object returnValue = method.invoke(targer, args);
                            System.out.println("jdk代理提交");
                            return returnValue;
                        }
                    });
        }
    }
    

• CLient

  • public class Client {
        public static void main(String[] args) {
            Teacher target = new TeacherDao();
            Teacher proxyInstance = (Teacher) new ProxyFactory(target).getProxyInstance();
            proxyInstance.teach();
        }
    }
    

运行结果：

jdk代理开始
老师正在授课
jdk代理提交