seata eureka 全局事务编号传递关键代码

seata eureka 全局事务编号传递关键代码

网文大部分是基于dobbo的分析，eureka传递xid(全局事务编号)的分析目前还没找到，断点跟踪了seata-sample的工程
seata-sample地址：https://github.com/seata/seata-samples
seata版本：0.6.1
关键依赖

            
                org.springframework.cloud
                spring-cloud-alibaba-seata
                0.9.1.BUILD-SNAPSHOT
                
                    
                        io.seata
                        seata-spring
                    
                
            
            
                io.seata
                seata-all
                ${seata.version}
            

构建feign请求头

package org.springframework.cloud.alibaba.seata.rest;

import io.seata.core.context.RootContext;
import java.io.IOException;
import org.springframework.http.HttpRequest;
import org.springframework.http.client.ClientHttpRequestExecution;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.http.client.support.HttpRequestWrapper;
import org.springframework.util.StringUtils;

public class SeataRestTemplateInterceptor implements ClientHttpRequestInterceptor {
    public SeataRestTemplateInterceptor() {
    }

    public ClientHttpResponse intercept(HttpRequest httpRequest, byte[] bytes, ClientHttpRequestExecution clientHttpRequestExecution) throws IOException {
        HttpRequestWrapper requestWrapper = new HttpRequestWrapper(httpRequest);
        String xid = RootContext.getXID();
        if(!StringUtils.isEmpty(xid)) {
            //构建请求头
            requestWrapper.getHeaders().add("TX_XID", xid);
        }

        return clientHttpRequestExecution.execute(requestWrapper, bytes);
    }
}

获取xid放入seata上下文

package org.springframework.cloud.alibaba.seata.web;

import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

public class SeataHandlerInterceptorConfiguration implements WebMvcConfigurer {
    public SeataHandlerInterceptorConfiguration() {
    }

    public void addInterceptors(InterceptorRegistry registry) {
    	//注册HandlerInterceptor，拦截所有请求
        registry.addInterceptor(new SeataHandlerInterceptor()).addPathPatterns(new String[]{"/**"});
    }
}

package org.springframework.cloud.alibaba.seata.web;

import io.seata.core.context.RootContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.StringUtils;
import org.springframework.web.servlet.HandlerInterceptor;

public class SeataHandlerInterceptor implements HandlerInterceptor {
    private static final Logger log = LoggerFactory.getLogger(SeataHandlerInterceptor.class);

    public SeataHandlerInterceptor() {
    }

    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
        String xid = RootContext.getXID();
        String rpcXid = request.getHeader("TX_XID");
        //获取全局事务编号
        if(log.isDebugEnabled()) {
            log.debug("xid in RootContext {} xid in RpcContext {}", xid, rpcXid);
        }

        if(xid == null && rpcXid != null) {
            //设置全局事务编号
            RootContext.bind(rpcXid);
            if(log.isDebugEnabled()) {
                log.debug("bind {} to RootContext", rpcXid);
            }
        }

        return true;
    }

    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception e) {
        String rpcXid = request.getHeader("TX_XID");
        if(!StringUtils.isEmpty(rpcXid)) {
            String unbindXid = RootContext.unbind();
            if(log.isDebugEnabled()) {
                log.debug("unbind {} from RootContext", unbindXid);
            }

            if(!rpcXid.equalsIgnoreCase(unbindXid)) {
                log.warn("xid in change during RPC from {} to {}", rpcXid, unbindXid);
                if(unbindXid != null) {
                    RootContext.bind(unbindXid);
                    log.warn("bind {} back to RootContext", unbindXid);
                }
            }

        }
    }
}

以上就是服务中心基于eureka的feign调用时传递及获取xid(全局事务编号)的核心代码