ThreadLocal之美！

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/**
 * @Author：Joseph
 * @bolg：https://li-huancheng.gitee.io/
 * @Package：threadLocal
 * @Project：bing-fa-demo
 * @name：ThreadLocalDateTest
 * @Date：2023-07-21 15:36
 * @Filename：ThreadLocalDateTest
 */
public class ThreadLocalDateTest {
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    public static ExecutorService theadPool = Executors.newFixedThreadPool(10);
​
    public static void main(String[] args) {
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        for (int i = 0; i < 1000; i++) {
            int finalI = i;
            theadPool.submit(new Runnable() {
                @Override
                public void run() {
                    String date = new ThreadLocalDateTest().date(finalI);
                    System.out.println(date);
                }
            });
        }
​
​
    }
    public String date(int seconds){
​
        //从1970：1。1.0.0 00：00：00    GMT计sh'j
        // 因为Data是毫秒单位，标识秒，得乘1000
        Date date = new Date(1000*seconds);
        //格式化
//        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd:hh:mm: ss");
        SimpleDateFormat dateFormat = ThreadSafeFormatter.dateFormatThreadLocal.get();
        return dateFormat.format(date);
​
    }
​
}
class ThreadSafeFormatter{
    public static ThreadLocal<SimpleDateFormat> dateFormatThreadLocal = new ThreadLocal<>(){
        @Override
        protected SimpleDateFormat initialValue() {
            return new SimpleDateFormat("yyyy-MM-dd:hh:mm: ss");
        }
    };
​
}

Slf4j
public class LoginInterceptor implements HandlerInterceptor {
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    public static ThreadLocal<LoginUser> threadLocal = new ThreadLocal<>();
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    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
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        String accessToken = request.getHeader("token");
        if(accessToken == null ){
            accessToken = request.getParameter("token");
​
        }
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        if(StringUtils.isNotBlank(accessToken)){
            //不为空
            Claims claims = JWTUtil.checkJWT(accessToken);
            if(claims == null){
                 //未登录
                CommonUtil.sendJsonMessage(response, JsonData.buildResult(BizCodeEnum.ACCOUNT_UNLOGIN));
                return false;
​
            }
            long userId= Long.valueOf(claims.get("id").toString());
            String headImg = (String)claims.get("head_img");
            String name = (String)claims.get("name");
            String mail = (String) claims.get("mail");
​
            LoginUser loginUser = LoginUser.builder()
                    .headImg(headImg)
                    .name(name)
                    .id(userId)
                    .mail(mail).build();
​
​
            //通过attribute传递用户信息
            //request.setAttribute("loginUser",loginUser);
​
            //通过threadlocal传递用户登录信息
            threadLocal.set(loginUser);
​
            return true;
​
​
​
        }
        CommonUtil.sendJsonMessage(response,JsonData.buildResult(BizCodeEnum.ACCOUNT_UNLOGIN));
​
        return false;
    }
​
    @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 {
        threadLocal.remove();
    }
}
​

**
 * @Author：Joseph
 * @bolg：https://li-huancheng.gitee.io/
 * @Package：threadLocal
 * @Project：bing-fa-demo
 * @name：ThreadLoaclNullPointer
 * @Date：2023-07-23 11:59
 * @Filename：ThreadLoaclNullPointer
 */
public class ThreadLoaclNullPointer {
​
    ThreadLocal<Long> longThreadLocal= new ThreadLocal<Long>();
    public void set(){
        longThreadLocal.set(Thread.currentThread().getId());
    }
    public long get(){
        return longThreadLocal.get();
    }
​
    public static void main(String[] args) {
        ThreadLoaclNullPointer threadLoaclNullPointer = new ThreadLoaclNullPointer();
        Thread thread = new Thread(new Runnable() {
            @Override
            public void run() {
                System.out.println(threadLoaclNullPointer.get());
            }
        });
        thread.start();
    }
}
​

//修改为Long
public Long get(){
        return longThreadLocal.get();
    }