Spring AOP本质(7)

Spring AOP本质(7)

 

上一个里面，给出静态方法切点匹配的例子，如今给出一个动态的实现例子：

 

没有

 

/**
* 业务组件
*/
public class SampleBean {
     public void foo( int x) {
        System.out.println( "SampleBean的foo(int x)方法被调用,参数x="  +x);
    }
     public void bar() {  
        System.out.println( "SampleBean的无参bar()方法被调用!");
    }
}

 

import java.lang.reflect.Method;

import org.springframework.aop.ClassFilter;
import org.springframework.aop.support.DynamicMethodMatcherPointcut;

/**
* 自定义动态切入点:Pointcut
*/
public class SimpleDynamicPointcut extends DynamicMethodMatcherPointcut {
     /**
     * 重写了静态方法匹配器
     */
     public boolean matches(Method method, Class cls) {
        System.out.println( "SimpleDynamicPointcut:静态方法匹配器正在尝试匹配方法:" + method.getName());
         //仅当方法名为foo时候才匹配
         return ( "foo".equals(method.getName()));
    }

     /**
     * 实现了动态方法匹配器
     */
     public boolean matches(Method method, Class cls, Object[] args) {
        System.out.println( "SimpleDynamicPointcut:动态方法匹配器正在尝试匹配方法:" + method.getName());
         int x = ((Integer) args[0]).intValue();
         //仅当方法参数为不等于100才匹配
         return (x != 100);
    }

     /**
     * 重写了类匹配器
     */
     public ClassFilter getClassFilter() {
         return new ClassFilter() {
             public boolean matches(Class cls) {
                System.out.println( "SimpleDynamicPointcut:切入点类匹配,正在匹配"+cls.getName()+ "类!");                
                 return (cls == SampleBean. class);
            }
        };
    }
}

 

/**
* 自定义通知：Advice
*/
public class SimpleAdvice implements MethodInterceptor {
     public Object invoke(MethodInvocation invocation) throws Throwable {
        System.out.println( ">> 业务方法调用前动做，被代理调用目标方法是： " + invocation.getMethod().getName());
        Object retVal = invocation.proceed();
        System.out.println( ">> 业务方法调用结束后动做！");
         return retVal;
    }
}

 

import org.springframework.aop.Advisor;
import org.springframework.aop.framework.ProxyFactory;
import org.springframework.aop.support.DefaultPointcutAdvisor;

import com.apress.prospring.ch6.staticpc.SimpleAdvice;

/**
* 动态方法匹配器切入点:客户端测试
*/
public class DynamicPointcutExample {

     public static void main(String[] args) {
         //建立目标对象
        SampleBean target = new SampleBean();

         // 建立通知者
        Advisor advisor = new DefaultPointcutAdvisor(
                 new SimpleDynamicPointcut(), new SimpleAdvice());
        
         //建立代理工厂
        ProxyFactory pf = new ProxyFactory();
         //将目标加入工厂
        pf.setTarget(target);
         //建立通知者
        pf.addAdvisor(advisor);

         //获取代理实例(产品)
        SampleBean proxy = (SampleBean)pf.getProxy();

         //调用代理方法,注意参数的变化
        proxy.foo(1);
        proxy.foo(10);
        proxy.foo(100);
        
        proxy.bar();
        proxy.bar();
        proxy.bar();
    }
}

 

运行结果：

- Using JDK 1.4 collections
SimpleDynamicPointcut:切入点类匹配,正在匹配com.apress.prospring.ch6.dynamicpc.SampleBean类!
SimpleDynamicPointcut:静态方法匹配器正在尝试匹配方法:foo
SimpleDynamicPointcut:切入点类匹配,正在匹配com.apress.prospring.ch6.dynamicpc.SampleBean类!
SimpleDynamicPointcut:静态方法匹配器正在尝试匹配方法:bar
SimpleDynamicPointcut:切入点类匹配,正在匹配com.apress.prospring.ch6.dynamicpc.SampleBean类!
SimpleDynamicPointcut:静态方法匹配器正在尝试匹配方法:hashCode
SimpleDynamicPointcut:切入点类匹配,正在匹配com.apress.prospring.ch6.dynamicpc.SampleBean类!
SimpleDynamicPointcut:静态方法匹配器正在尝试匹配方法:toString
SimpleDynamicPointcut:切入点类匹配,正在匹配com.apress.prospring.ch6.dynamicpc.SampleBean类!
SimpleDynamicPointcut:静态方法匹配器正在尝试匹配方法:foo
SimpleDynamicPointcut:动态方法匹配器正在尝试匹配方法:foo
>> 业务方法调用前动做，被代理调用目标方法是： foo
SampleBean的foo( int x)方法被调用,参数x=1
>> 业务方法调用结束后动做！
SimpleDynamicPointcut:动态方法匹配器正在尝试匹配方法:foo
>> 业务方法调用前动做，被代理调用目标方法是： foo
SampleBean的foo( int x)方法被调用,参数x=10
>> 业务方法调用结束后动做！
SimpleDynamicPointcut:动态方法匹配器正在尝试匹配方法:foo
SampleBean的foo( int x)方法被调用,参数x=100 SampleBean的无参bar()方法被调用! SampleBean的无参bar()方法被调用! SampleBean的无参bar()方法被调用! Process finished with exit code 0