在上一节中，我们通过Advice可以对目标类进行增强，使得目标类在调用的时候可以执行增强类中的代码，但是，增强类适配了目标类中的所有方法。如果我们只需要对目标类中的部分方法使用增强类，该如何操作呢？比如我们上一节的场景：乘客乘坐火车，在上车之前需要检票，在这一节中我们继续添加一项业务：旅客服务。 相关代码：
public interface TakingTrain { public void takeTrain(String name) throws RestException; public void customSerive(String name);}//接口的实现public void customSerive(String name) { System.out.println("Hi, "+name+" ,may i help you?"); } 修改我们的测试类代码： 添加:proxy.customSerive("LaoWang");
@Test public void testAdivice(){ ProxyFactory factory = new ProxyFactory(); TakingTrain trainImpl = new TakingTrainImpl(); factory.setInterfaces(trainImpl.getClass().getInterfaces()); factory.setTarget(trainImpl); factory.addAdvice(new CheckTicketAdvice()); TakingTrain proxy = (TakingTrain) factory.getProxy(); try { proxy.takeTrain("LaoWang"); proxy.customSerive("LaoWang"); } catch (RestException e) { } } 打印结果：
please show your tickesHi LaoWang Welcome to take the trainplease show your tickesHi, LaoWang ,may i help you?
这个时候我们发现 please show your tickes这句话打印了两遍。也就是说CheckTicketAdvice中的方法执行了两遍。这可不是我们想要的结果。 而我们现在需要的是对TakingTrain 中的 takeTrain 方法之前调用。而不是所有的方法都调用。 用什么方法可以实现这个功能呢？AOP！它可以通过切面讲增强类有选择的织入到目标类的特定方法中。 换句话说，我们需要两个功能：
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拦截类:ClassFilter
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拦截方法:MethodMatcher
相关的类图 
具体实现(使用静态方法匹配切面)：
1.定义切面,在切面内可进行类级别和方法级别的拦截。 注意，将切点设置到切面内：
public class StaticMethodCheckTicketAdvisor extends StaticMethodMatcherPointcutAdvisor{ public StaticMethodCheckTicketAdvisor(Advice advice) { this.setAdvice(advice); } @Override public boolean matches(Method method, Class targetClass) { return "takeTrain".equals(method.getName()); }} 2.切点保持不变：
public class CheckTicketAdvice implements MethodBeforeAdvice{ @Override public void before(Method method, Object[] args, Object target) throws Throwable { System.out.println("please show your tickes"); }} 3.实现类：
@Test public void testStaticMethodAdvisor(){ ProxyFactory factory = new ProxyFactory(); StaticMethodCheckTicketAdvisor advisor = new StaticMethodCheckTicketAdvisor(new CheckTicketAdvice()); TakingTrain trainImpl = new TakingTrainImpl(); factory.setInterfaces(trainImpl.getClass().getInterfaces()); factory.setTarget(trainImpl); factory.addAdvisor(advisor); TakingTrain proxy = (TakingTrain) factory.getProxy(); try { proxy.takeTrain("LaoWang"); proxy.customSerive("LaoWang"); } catch (RestException e) { } } 4.打印结果：
please show your tickesHi LaoWang Welcome to take the trainHi, LaoWang ,may i help you?
具体实现(使用表达式匹配切面)：
1.定义切面,在切面内可进行类级别和方法级别的拦截。 注意，将切点，以及表达式设置到切面内：
public class RegexpMethodCheckTicketAdvisor extends RegexpMethodPointcutAdvisor{ public RegexpMethodCheckTicketAdvisor() { super(); // TODO Auto-generated constructor stub } public RegexpMethodCheckTicketAdvisor(Advice advice) { super(advice); // TODO Auto-generated constructor stub } public RegexpMethodCheckTicketAdvisor(String pattern, Advice advice) { super(pattern, advice); // TODO Auto-generated constructor stub } public RegexpMethodCheckTicketAdvisor(String[] patterns, Advice advice) { super(patterns, advice); // TODO Auto-generated constructor stub } } 2.切点保持不变：
public class CheckTicketAdvice implements MethodBeforeAdvice{ @Override public void before(Method method, Object[] args, Object target) throws Throwable { System.out.println("please show your tickes"); }} 3.实现类：
@Test public void testRegexpMethodAdvisor(){ ProxyFactory factory = new ProxyFactory(); RegexpMethodCheckTicketAdvisor advisor = new RegexpMethodCheckTicketAdvisor(); advisor.setPattern(".*takeTrain.*"); advisor.setAdvice(new CheckTicketAdvice()); TakingTrain trainImpl = new TakingTrainImpl(); factory.setInterfaces(trainImpl.getClass().getInterfaces()); factory.setTarget(trainImpl); factory.addAdvisor(advisor); TakingTrain proxy = (TakingTrain) factory.getProxy(); try { proxy.takeTrain("LaoWang"); proxy.customSerive("LaoWang"); } catch (RestException e) { } } 4.打印结果：
please show your tickesHi LaoWang Welcome to take the trainHi, LaoWang ,may i help you?