spring AOP

一、简单的拦截

（1）、运行前拦截 org.springframework.aop.MethodBeforeAdvice

（2）、运行后拦截 org.springframework.aop.AfterReturningAdvice

（3）、抛出异常拦截 org.springframework.aop.ThrowsAdvice

（4）、围绕拦截 org.aopalliance.intercept.MethodInterceptor

demo如下

（1）、待拦截的服务

import org.springframework.stereotype.Component;

@Component
public class HelloService {
public String say(String name) throws Exception {
return "hello:" + name;
}
}

（2）、拦截服务类

import java.lang.reflect.Method;

import org.springframework.aop.MethodBeforeAdvice;
import org.springframework.stereotype.Component;

@Component
public class MyBeforeAdvice implements MethodBeforeAdvice {

@Override
public void before(Method method, Object[] args, Object target) throws Throwable {
System.out.println("hello,i am before advice");
}

}

import java.lang.reflect.Method;

import org.springframework.aop.AfterReturningAdvice;
import org.springframework.stereotype.Component;

@Component
public class MyAfterAdvice implements AfterReturningAdvice {

@Override
public void afterReturning(Object returnValue, Method method, Object[] args, Object target) throws Throwable {
System.out.println("hello,i am after advice");
}

}

import org.springframework.aop.ThrowsAdvice;
import org.springframework.stereotype.Component;

@Component
public class MyThrowAdvice implements ThrowsAdvice {

public void afterThrowing(IllegalArgumentException e) throws Throwable {
System.out.println("HijackThrowException : Throw exception hijacked!");
}
}

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.springframework.stereotype.Component;

@Component
public class MyAroundAdvice implements MethodInterceptor {

public Object invoke(MethodInvocation methodInvocation) throws Throwable {
System.out.println("before method");

try {
// 调用原方法
Object result = methodInvocation.proceed();

System.out.println("after method");

return result;
} catch (IllegalArgumentException e) {
// 相当于 ThrowsAdvice
System.out.println("catch exception");
throw e;
}
}

}

（3）、服务注册，采用代理方式实现

import org.springframework.aop.framework.ProxyFactoryBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class AdviceConfig {
@Autowired HelloService helloService;

@Bean(name="beforeAdvice")
public ProxyFactoryBean beforeAdvice(){
ProxyFactoryBean proxyFactoryBean = new ProxyFactoryBean();
proxyFactoryBean.setTarget(helloService);
proxyFactoryBean.setInterfaces(MyBeforeAdvice.class);

return proxyFactoryBean;
}

@Bean(name="afterAdvice")
public ProxyFactoryBean afterAdvice(){
ProxyFactoryBean proxyFactoryBean = new ProxyFactoryBean();
proxyFactoryBean.setTarget(helloService);
proxyFactoryBean.setInterfaces(MyAfterAdvice.class);

return proxyFactoryBean;
}

@Bean(name="throwAdvice")
public ProxyFactoryBean throwAdvice(){
ProxyFactoryBean proxyFactoryBean = new ProxyFactoryBean();
proxyFactoryBean.setTarget(helloService);
proxyFactoryBean.setInterfaces(MyThrowAdvice.class);

return proxyFactoryBean;
}

@Bean(name="aroundAdvice")
public ProxyFactoryBean aroundAdvice(){
ProxyFactoryBean proxyFactoryBean = new ProxyFactoryBean();
proxyFactoryBean.setTarget(helloService);
proxyFactoryBean.setInterfaces(MyAroundAdvice.class);

return proxyFactoryBean;
}
}