aop作为Spring这个轻量级的容器中很重要的一部分，得到越来越多的关注，Spring的Transaction就是用aop来管理的，今天就通过简单的例子来看看Spring中的aop的基本使用方法。 首先确定将要Proxy的目标，在Spring中默认采用JDK中的dynamic proxy，它只能够实现接口的代理，如果想对类进行代理的话，需要采用CGLIB的proxy。显然，选择“编程到接口”是更明智的做法，下面是将要代理的接口： public interface FooInterface { ...
横切技术： “横切”是aop的专有名词。它是一种蕴含强大力量的相对简单的设计和编程技术，尤其是用于建立松散耦合的、可扩展的企业系统时。横切技术可以使得aop在一个给定的编程模型中穿越既定的职责部分（比如日志记录和性能优化）的操作。 如果不使用横切技术，软件开发是怎样的情形呢？在传统的程序中，由于横切行为的实现是分散的，开发人员很难对这些行为进行逻辑上的实现或更改。例如，用于日志记录的代码和主要用于其...
最近闲着没事，就把之前自己弄的spring的aop给看了一下，呵呵用的是jdk1.4的版本，这个例子只是用aop做了一个数据库打开和关闭的拦截。 1.定义一个数据库链接类如下: package db; import java.sql.Connection; import java.sql.SQLException; import javax.sql.DataSource; public class ConnectionManager { private DataSource datasource; public void setDatasource(DataSource ds){ this.datasource...
一，从代理机制初探aop 1，使用静态代理 #代理对象和被代理对象必须实现共同的接口 package com.biaoflying; public interface IHello { public void hello(String name); } #代理对象HelloProxy package com.biaoflying; import java.util.logging.*; public class HelloProxy implements IHello { private IHello helloObject; private Logger logger= Logger.getLogger(this.getClass().g...
事实:一个顾客买果酱. 你想在这个顾客买果酱之前说一句问候语:Dear,how do you do!. 这时候,我们可以用Spring的aop来实现. 1. 定义一个接口Buy public interface Buy{ public void buySquish(String buyer); } 2. 实现这个接口 public class BuyImpl{ public void buySquish(String buyer){ System.out.println(buyer + " buy a squish!"); } } 3. 构造一个通知. public class BuyBefo...
6.4. Choosing which aop declaration style to use Once you have decided that an aspect is the best approach for implementing a given requirement, how do you decide between using Spring aop or AspectJ, and between the Aspect language (code) style, @AspectJ annotation style, and the XML style? These decisions are influenced by a number of factors including application requirements, de...
6.3. Schema-based aop support If you are unable to use Java 5, or simply prefer an XML-based format, then Spring 2.0 also offers support for defining aspects using the new "aop" namespace tags. The exact same pointcut expressions and advice kinds are supported as when using the @AspectJ style, hence in this section we will focus on the new syntax and refer the reader to the discuss...
6.2.4. Declaring advice Advice is associated with a pointcut expression, and runs before, after, or around method executions matched by the pointcut. The pointcut expression may be either a simple reference to a named pointcut, or a pointcut expression declared in place. 6.2.4.1. Before advice Before advice is declared in an aspect using the @Before annotation: import org.aspectj.lang....
6.1. Introduction Aspect-Oriented Programming (aop) complements Object-Oriented Programming (OOP) by providing another way of thinking about program structure. In addition to classes, aop gives you aspects. Aspects enable modularization of concerns such as transaction management that cut across multiple types and objects. (Such concerns are often termed crosscutting concern...
