springboot登录拦截器+ThreadLocal实现用户信息存储的实例代码

static class Entry extends WeakReference<ThreadLocal<?>> {
        /** The value associated with this ThreadLocal. */
        Object value;
        Entry(ThreadLocal<?> k, Object v) {
            super(k);
            value = v;
        }
    }
}

@Component
public class HostHolder {
    private ThreadLocal<User> users = new ThreadLocal<>();
    public User getUser() {
        return users.get();
    }
    public void setUser(User user) {
        users.set(user);
    }
    public void clear() {
        users.remove();
    }
}

/**
 * 登录拦截器
 */
public class LoginInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        // 在请求处理之前进行调用，返回true则继续向下执行，返回false则中断请求
        String loginId = request.getHeader("loginId");
        if (StringUtils.isNotBlank(loginId)) {
            // 如果请求头中包含loginId，将其设置到LoginContextHolder中
            LoginContextHolder.set("loginId", loginId);
        }
        return true;
    }
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        // 在整个请求结束之后被调用，也就是在DispatcherServlet渲染了对应的视图之后执行，主要是做清理工作
        // 移除LoginContextHolder中的loginId
        LoginContextHolder.remove();
    }
}