hmall 微服务项目排错与知识点总结#

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org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
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  com.hmall.common.config.MyBatisConfig,\
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  com.hmall.common.config.MqConfig,\
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  com.hmall.common.config.JsonConfig,\
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  com.hmall.common.config.MvcConfig

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@Configuration
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@ConditionalOnClass(MessageConverter.class)
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public class MqConfig {
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    @Bean
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    public MessageConverter messageConverter(){
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        return new Jackson2JsonMessageConverter();
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    }
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}

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public class UserContext {
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    private static final ThreadLocal<Long> tl = new ThreadLocal<>();
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    public static void setUser(Long userId) { tl.set(userId); }
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    public static Long getUser() { return tl.get(); }
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    public static void removeUser() { tl.remove(); }
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}

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浏览器 --JWT--> 网关验签得到 userId
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网关 --(加 user-info 请求头)--> 微服务
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微服务拦截器读头 -> UserContext.setUser()
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微服务A --Feign 新 HTTP 请求(需 RequestInterceptor 复制头)--> 微服务B
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微服务B 拦截器读头 -> 重建 UserContext

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// 把 userId 放入名为 user-info 的请求头
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ServerHttpRequest newRequest = request.mutate()
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        .header("user-info", userId.toString())
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        .build();
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ServerWebExchange newExchange = exchange.mutate().request(newRequest).build();
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return chain.filter(newExchange);

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public class UserInfoInterceptor implements HandlerInterceptor {
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    @Override
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    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
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        // 1.从请求头取网关传来的用户信息
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        String userInfo = request.getHeader("user-info");
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        // 2.非空则存入 ThreadLocal
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        if (StrUtil.isNotBlank(userInfo)) {
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            UserContext.setUser(Long.valueOf(userInfo));
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        }
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        // 3.放行
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        return true;
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    }
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    @Override
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    public void afterCompletion(HttpServletRequest req, HttpServletResponse resp, Object handler, Exception ex) {
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        // 4.请求结束清理，避免线程池复用导致用户串号
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        UserContext.removeUser();
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    }
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}

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@Configuration
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@ConditionalOnClass({DispatcherServlet.class, HttpServletRequest.class})
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public class MvcConfig implements WebMvcConfigurer {
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    @Override
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    public void addInterceptors(InterceptorRegistry registry) {
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        registry.addInterceptor(new UserInfoInterceptor());
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    }
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}

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@Bean
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public RequestInterceptor userInfoRequestInterceptor() {
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    return template -> {
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        // 1.拿到当前线程正在处理的"入站请求"
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        ServletRequestAttributes attrs =
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                (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
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        if (attrs == null) {
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            // 没有请求上下文（MQ 监听器、定时任务等异步线程），直接跳过
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            return;
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        }
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        // 2.从入站请求头里取出网关注入的 user-info
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        String userId = attrs.getRequest().getHeader("user-info");
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        // 3.写入 Feign 即将发出的"出站请求"头里
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        if (StrUtil.isNotBlank(userId)) {
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            template.header("user-info", userId);
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        }
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    };
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}