Seata

标签：RootContext xid Seata request Request seataXid headers

 

 

Seata事务ID的传递

https://www.cnblogs.com/ciel717/p/16185061.html

• 发送：SeataFeignClient替换了默认的feignClient，把xid放到了requestHeader里。

　　SeataFeignClient.execute：塞到消息头

@Override
public Response execute(Request request, Request.Options options) throws IOException {
    //设置xid
    Request modifiedRequest = getModifyRequest(request);
    //调用下游服务
    return this.delegate.execute(modifiedRequest, options);
}

private Request getModifyRequest(Request request) {
    String xid = RootContext.getXID();
    if (StringUtils.isEmpty(xid)) {
        return request;
    }
    Map<String, Collection<String>> headers = new HashMap<>(MAP_SIZE);
    //设置xid到消息头
    headers.putAll(request.headers());
    List<String> seataXid = new ArrayList<>();
    seataXid.add(xid);
    headers.put(RootContext.KEY_XID, seataXid);
    return Request.create(request.method(), request.url(), headers, request.body(),request.charset());
}

• 接收：拦截器实现

　　　SeataHandlerInterceptor.preHandle()：通过WebMvcConfigure::addInterceptors中绑定该拦截器

@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response,Object handler) {
    String xid = RootContext.getXID();
    //从消息头中获取xid
    String rpcXid = request.getHeader(RootContext.KEY_XID);
    if (log.isDebugEnabled()) {
        log.debug("xid in RootContext {} xid in RpcContext {}", xid, rpcXid);
    }
    if (xid == null && rpcXid != null) {
        // 设置xid
        RootContext.bind(rpcXid);
        if (log.isDebugEnabled()) {
            log.debug("bind {} to RootContext", rpcXid);
        }
    }
    return true;
}

 

 

 

@OverridepublicResponseexecute(Request request, Request.Options options) throws IOException { //设置xidRequest modifiedRequest = getModifyRequest(request); //调用下游服务returnthis.delegate.execute(modifiedRequest, options); } privateRequestgetModifyRequest(Request request) { String xid = RootContext.getXID(); if (StringUtils.isEmpty(xid)) { return request; } Map<String, Collection<String>> headers = newHashMap<>(MAP_SIZE); //设置xid到消息头 headers.putAll(request.headers()); List<String> seataXid = newArrayList<>(); seataXid.add(xid); headers.put(RootContext.KEY_XID, seataXid); returnRequest.create(request.method(), request.url(), headers, request.body(),request.charset()); }

标签：RootContext,xid,Seata,request,Request,seataXid,headers
From： https://www.cnblogs.com/clarino/p/16972033.html