Sometimes we may think about how to do something before the method runs
有时我们会想，如何在一些方法执行前或者执行后做一些操作
比如日志的记录、权限的鉴定等等
昨天，我们搭建了个简单的spring项目并写了几个接口
其中一个是这样的
这里返回给前端的map中的data，我是手动加的前缀“服务器对你说”
我们现在来用AOP实现
先修改我们接口中的代码，去掉前缀
然后配置AOP
<?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:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.2.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.2.xsd">
<context:component-scan base-package="com.ruben.controller"/>
<mvc:annotation-driven/>
<mvc:default-servlet-handler/>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/"/>
<property name="suffix" value=".jsp"/>
</bean>
<mvc:resources location="/static/" mapping="/static/**"/>
<context:component-scan base-package="com.ruben.aop"/>
<aop:aspectj-autoproxy proxy-target-class="true"/>
</beans>
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然后创建我们的aop包
在aop包创建一个类，并加上注解
定义我们的切入点，也就是需要被织入的位置
@Pointcut("execution(* com.ruben.controller.UserController.say(..))")
private void pointcut() {
}
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然后编写我们的切面
@AfterReturning(pointcut = "pointcut()", returning = "returnValue")
public void addPrefix(JoinPoint point, Object returnValue) {
if (returnValue instanceof HashMap) {
Map<String, Object> result = (Map<String, Object>) returnValue;
result.put("data", "achao对你说：" + result.get("data"));
}
}
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完整代码
package com.ruben.aop;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.stereotype.Component;
import java.util.HashMap;
import java.util.Map;
@Aspect
@Component
public class SayWordAop {
@Pointcut("execution(* com.ruben.controller.UserController.say(..))")
private void pointcut() {
}
@AfterReturning(pointcut = "pointcut()", returning = "returnValue")
public void addPrefix(JoinPoint point, Object returnValue) {
if (returnValue instanceof HashMap) {
Map<String, Object> result = (Map<String, Object>) returnValue;
result.put("data", "achao对你说：" + result.get("data"));
}
}
}
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然后启动我们的项目，发现切面生效了
发送的参数为登录成功！
但是返回的结果是
说明我们的切面生效了，我们顺便把其他几种也加上吧
比如加个校验
@Around("execution(* com.ruben.controller.UserController.login(..))")
public Object permissionCheck(ProceedingJoinPoint point) throws Throwable {
List<Object> paramList = Arrays.asList(point.getArgs());
AtomicBoolean passValidate = new AtomicBoolean(true);
String pattern = "^[A-Za-z0-9]{4,40}$";
AtomicReference<String> errorMsg = new AtomicReference<>("您输入的参数格式有误");
paramList.forEach(param -> {
User user = (User) param;
if (!Pattern.matches(pattern, user.getUsername())) {
errorMsg.set("用户名格式错误");
passValidate.set(false);
} else if (!Pattern.matches(pattern, user.getPassword())) {
errorMsg.set("密码格式错误");
passValidate.set(false);
}
});
if (!passValidate.get()) {
Map<String, Object> map = new HashMap<>(1 << 2);
map.put("success", false);
map.put("code", -629);
map.put("msg", errorMsg.get());
return map;
}
return point.proceed();
}
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还比如在方法执行前后记录日志
先加上注解
然后修改配置文件
<context-param>
<param-name>log4jConfigLocation</param-name>
<param-value>/WEB-INF/config/log4j.properties</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
</listener>
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添加配置文件
log4j.rootLogger=INFO,console,file
log4j.appender.console=org.apache.log4j.ConsoleAppender
log4j.appender.console.Threshold=DEBUG
log4j.appender.console.layout=org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern=%-22d{yyyy/MM/dd HH:mm:ss}%m%n
log4j.appender.file=org.apache.log4j.FileAppender
log4j.appender.file.File=./logs/project.log
log4j.appender.file.Append=true
log4j.appender.file.Encoding=UTF-8
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=[%-5p][%-22d{yyyy/MM/dd HH:mm:ssS}][%l]%n%m%n
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就可以用log.info()打印日志啦！
@Before(value = "execution(* com.ruben.*.*.*(..))")
public void logRecode(JoinPoint point) {
ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
HttpServletRequest request = attributes.getRequest();
log.info("==>url：" + request.getRequestURI());
log.info("==>参数：" + Arrays.toString(point.getArgs()));
}
@After("execution(* com.ruben.controller.*.*(..))")
public void recodeWord(JoinPoint point) {
log.info("<==" + point.getSignature().getDeclaringTypeName()
+ "." + point.getSignature().getName() + "方法执行结束");
}
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2020/08/07 22:00:11 ==>url：/user/login
2020/08/07 22:00:11 ==>参数：[User(username=achao, password=ruben)]
2020/08/07 22:00:11 <==com.ruben.controller.UserController.login方法执行结束
2020/08/07 22:00:11 ==>url：/user/say
2020/08/07 22:00:11 ==>参数：[登录成功！]
2020/08/07 22:00:11 <==com.ruben.controller.UserController.say方法执行结束
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完整代码
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