ThreadLocal的使用

最新推荐文章于 2025-03-15 17:11:54 发布

最新推荐文章于 2025-03-15 17:11:54 发布 · 174 阅读

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#AOP #Spring #Servlet #Bean #JSP

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本文介绍如何使用 Spring AOP 在登录操作后进行拦截，将登录信息存入 ThreadLocal，以便后续流程使用。示例代码展示了 LoginServlet 和 LoginAspect 的实现细节。

我的这个例子是一个登录的例子:

用到Spring的Aop,在login()方法后用Aop来拦截,将用户登录信(username,password)写到ThreadLocal中,然后在其它地方再取出来用

代码如下:

LoginServlet.java

package com.yimei.drp.servlet.login;

import java.io.IOException;

import javax.servlet.Servlet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.yimei.drp.common.AuthCurrentUser;
import com.yimei.drp.model.user.UserInfo;
import com.yimei.drp.service.user.IUserService;

public class LoginServlet extends HttpServlet implements Servlet{

    private IUserService userService;

    public IUserService getUserService() {
        return userService;
    }

    public void setUserService(IUserService userService) {
        this.userService = userService;
    }

    public void service(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        userService.login("zj","123456");

        UserInfo userInfo = (UserInfo) AuthCurrentUser.get();
        System.out.println("===用户==="+userInfo.getUsername());
        System.out.println("===密码==="+userInfo.getPassword());

        request.getRequestDispatcher("/pages/login/main.jsp").forward(request, response);
    }


}

LoginAspect.java

package com.yimei.drp.aop.login;

import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;

import com.yimei.drp.common.AuthCurrentUser;
import com.yimei.drp.model.user.UserInfo;

@Aspect
public class LoginAspect {

    //@Pointcut("execution(* com.yimei.drp.service.user.IUserService.login(..))")
    //public void loginMethod(){};


    @Before("execution(* com.yimei.drp.service.user.IUserService.login(..))")
    //@Before(value="loginMethod()")
    public void loginBefore(){
        System.out.println("登录前");
    }

    @AfterReturning("execution(* com.yimei.drp.service.user.IUserService.login(..)) && args(username,password,..)")
//    //@AfterReturning(value="loginMethod() && args(username,..)")
    public void loginAfter(String username,String password){
        System.out.println(username+"已成功登录了");

        UserInfo userInfo=new UserInfo();
        userInfo.setUsername(username);
        userInfo.setPassword(password);

        AuthCurrentUser.set(userInfo);


    }

}

这个是关键

AuthCurrentUser.java

package com.yimei.drp.common;

import com.yimei.drp.model.user.UserInfo;

public class AuthCurrentUser {

    /**
    * 声明局部线程变量
    */
    private static ThreadLocal<UserInfo> currentUser = new ThreadLocal<UserInfo>();

    /**
    * 设置当前用户对象
    *
    * @param user 用户值对象
    */
    public static void set(UserInfo user) {
        currentUser.set(user);
    }

    /**
    * 获取当前用户对象
    *
    * @return 当前用户对象
    */
    public static UserInfo get() {
        return (UserInfo) currentUser.get();
    }

}

aop的配置文件

<?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:tx="http://www.springframework.org/schema/tx"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="
    http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
    http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd"
    default-autowire="byName" default-lazy-init="true">

    
    <aop:aspectj-autoproxy />

    <bean id="loginAspect" class="com.yimei.drp.aop.login.LoginAspect" />

</beans>