一个简易的SpringAOP实例

1、引入依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>org.example</groupId><artifactId>SpringAop_demo</artifactId><version>1.0-SNAPSHOT</version><properties><maven.compiler.source>8</maven.compiler.source><maven.compiler.target>8</maven.compiler.target></properties><dependencies><!-- Spring Core --><dependency><groupId>org.springframework</groupId><artifactId>spring-core</artifactId><version>5.3.9</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId><version>5.3.9</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-beans</artifactId><version>5.3.9</version></dependency><!-- Spring AOP --><dependency><groupId>org.springframework</groupId><artifactId>spring-aop</artifactId><version>5.3.9</version></dependency><!-- AspectJ Weaver --><dependency><groupId>org.aspectj</groupId><artifactId>aspectjweaver</artifactId><version>1.9.7</version></dependency><!-- AspectJ RT --><dependency><groupId>org.aspectj</groupId><artifactId>aspectjrt</artifactId><version>1.9.7</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-tx</artifactId><version>5.3.22</version></dependency></dependencies></project>

2、xml配置

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:aop="http://www.springframework.org/schema/aop"xsi:schemaLocation="http://www.springframework.org/schema/beanshttps://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/aophttps://www.springframework.org/schema/aop/spring-aop.xsdhttp://www.springframework.org/schema/contexthttps://www.springframework.org/schema/context/spring-context.xsd"><aop:aspectj-autoproxy /><!--目标类--><bean id="calculator" class="BasicCalculator" /><!--切面--><bean id="loggingAspect" class="LoggingAspect" /><aop:config><!--配置切面--><aop:aspect ref="loggingAspect"><!--配置切入点--><aop:pointcut id="pointMethod" expression="execution(* BasicCalculator.*(..))"/><aop:after-returning method="finallyAdd" pointcut-ref="pointMethod" returning="joinPoint"/></aop:aspect></aop:config>
</beans>

3、被代理对象接口与被代理对象

public interface Calculator {int add(int a, int b);
}

import org.springframework.aop.aspectj.AspectJExpressionPointcut;public class BasicCalculator implements Calculator {@Overridepublic int add(int a, int b) {int c = 0;try {System.out.println("add method into method add...");c = a + b;System.out.println("add method will return....");return c;}catch (Exception e){System.out.println("add method is error....");e.printStackTrace();}finally {System.out.println("add method is finally....");}return c;}
}

4、主函数

import org.springframework.aop.aspectj.AspectJExpressionPointcut;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;public class Main {public static void main(String[] args) {ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");Calculator calculator = context.getBean(Calculator.class);int result = calculator.add(5, 3);System.out.println("Result: " + result);}}

还有一种可以写法，直接运行即可

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.springframework.aop.aspectj.AspectJExpressionPointcut;
import org.springframework.aop.framework.ProxyFactory;
import org.springframework.aop.support.DefaultPointcutAdvisor;
import org.springframework.aop.support.StaticMethodMatcherPointcut;
import org.springframework.core.annotation.MergedAnnotations;
import org.springframework.transaction.annotation.Transactional;import java.lang.reflect.Method;public class tesAspect {public static void main(String[] args) throws NoSuchMethodException {//切点AspectJExpressionPointcut pointcut = new AspectJExpressionPointcut();pointcut.setExpression("execution(* *(..))");System.out.println(pointcut.matches(Target.class.getMethod("foo"), Target.class));//通知MethodInterceptor advice = new MethodInterceptor() {@Overridepublic Object invoke(MethodInvocation methodInvocation) throws Throwable {System.out.println("before..");Object result = methodInvocation.proceed();System.out.println("after..");return result;}};//切面DefaultPointcutAdvisor advisor = new DefaultPointcutAdvisor(pointcut, advice);Target target1 = new Target();ProxyFactory proxyFactory = new ProxyFactory();proxyFactory.setTarget(target1);proxyFactory.addAdvisor(advisor);A1 a1 = (A1) proxyFactory.getProxy();System.out.println(a1.getClass());a1.foo();a1.bar();//检查类与方法是否有Transaction注解StaticMethodMatcherPointcut pointcut1 = new StaticMethodMatcherPointcut() {@Overridepublic boolean matches(Method method, Class<?> aClass) {//检查方法上是否加了Transaction注解MergedAnnotations annotation = MergedAnnotations.from(method);if(annotation.isPresent(Transactional.class)){return true;}//检查方法上是否加了注解annotation = MergedAnnotations.from(aClass, MergedAnnotations.SearchStrategy.TYPE_HIERARCHY);if(annotation.isPresent(Transactional.class)){return true;}return false;}};System.out.println(pointcut1.matches(Target.class.getMethod("foo"), Target.class));}@Transactionalinterface A1{void foo();void bar();}static class Target implements A1{@Overridepublic void foo() {System.out.println("foo");}@Overridepublic void bar() {System.out.println("bar");}}
}