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SpringBoot中的ThreadLocal保存請求用戶信息的實(shí)例demo

更新時(shí)間：2024年05月30日 09:39:35 作者：奮--斗

線程局部變量,創(chuàng)建一個(gè)線程變量后,針對這個(gè)變量可以讓每個(gè)線程擁有自己的變量副本,每個(gè)線程是訪問的自己的副本,與其他線程的相互獨(dú)立,本文介紹SpringBoot中的ThreadLocal保存請求用戶信息,需要的朋友可以參考下

一、ThreadLocal概述

線程局部變量，創(chuàng)建一個(gè)線程變量后，針對這個(gè)變量可以讓每個(gè)線程擁有自己的變量副本，每個(gè)線程是訪問的自己的副本，與其他線程的相互獨(dú)立。

二、具體代碼demo實(shí)現(xiàn)

（1）創(chuàng)建user實(shí)例對象

@Data
public class UserDTO {
    private Long userId;
    private String UserName;
}

（2）創(chuàng)建UserThreadLocal對象

public class UserThreadLocal {
    private UserThreadLocal(){};
    private static final ThreadLocal<UserDTO> USER_DTO_THREAD_LOCAL = new ThreadLocal<>();
    /**
     * 清除信息
     */
    public static void clear(){
        USER_DTO_THREAD_LOCAL.remove();
    }
    /**
     * 保存用戶信息
     * @param userDTO
     */
    public static void set(UserDTO userDTO){
        USER_DTO_THREAD_LOCAL.set(userDTO);
    }
    public static UserDTO getCurrentUser(){
       return USER_DTO_THREAD_LOCAL.get();
    }
}

（3）創(chuàng)建用戶攔截器

@Component
public class UserInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //此處實(shí)際應(yīng)該根據(jù)header的token解析出用戶本處為了簡單，直接虛構(gòu)一個(gè)用戶
        UserDTO userDTo = new UserDTO();
        userDTo.setUserId(10001L);
        userDTo.setUserName("張三");
        UserThreadLocal.set(userDTo);
        return true;
    }
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
    }
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        UserThreadLocal.clear();
    }
}

(4) 注冊用戶攔截器

@Configuration
public class InterceptorConfig implements WebMvcConfigurer {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new UserInterceptor());
    }
}

（5）編寫測試接口

@RequestMapping("test")
@RestController
public class TestController {

    @GetMapping("get")
    public UserDTO getUser(){
        UserDTO currentUser = UserThreadLocal.getCurrentUser();
        System.out.println(currentUser);
        return currentUser;
    }
}