之前遇到过在分布式环境中不方便查找日志的问题,虽然现在的很多云服务环境都提供这种功能,但是在自己搭建的分布式环境中可以考虑应急的这样做,先记录下,以便下次快速使用
注意：MDC-traceId在分布式环境中使用步骤(下面的3456四个类在分布式用到的工程中都需要添加,可以考虑添加到第三方工程中统一在pom中引入)
1、 引入log4j的同时需要注意去除冲突包
org.springframework.boot
spring-boot-starter
org.springframework.boot
spring-boot-starter-logging
log4j
log4j
1.2.17
org.slf4j
slf4j-log4j12
1.7.21
2、resources 文件夹下添加[log4j.xml]配置文件
3、添加[MDCUtils]自定义工具类
public class MDCUtils {
public static String mdc(){
RequestAttributes requestAttributes = RequestContextHolder.getRequestAttributes();
HttpServletRequest request = (HttpServletRequest) requestAttributes
.resolveReference(RequestAttributes.REFERENCE_REQUEST);
String traceId;
String traceIdKey = "traceId";
if (request.getHeader(traceIdKey) == null) {
traceId = UUID.randomUUID().toString();
} else {
traceId = request.getHeader(traceIdKey);
}
return traceId;
}
}
4、添加拦截器[LogInterceptor]为每一个请求头添加[traceId]
public class LogInterceptor implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
String traceIdKey = "traceId";
String traceId = MDCUtils.mdc();
request.setAttribute(traceIdKey, traceId);
MDC.clear();
MDC.put(traceIdKey, traceId);
return true;
}
}
5、注册拦截器
@Configuration
public class WebMvcConfig implements WebMvcConfigurer {
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new LogInterceptor()).addPathPatterns("/test
URIBuilder uriBuilder = new URIBuilder(url);
// 第一种添加参数的形式
// 第二种添加参数的形式
// 加载参数
if (!CollectionUtils.isEmpty(paramMap)) {
List paramertersList = new linkedList<>();
Set keys = paramMap.keySet();
for (String s : keys) {
String key = String.valueOf(s);
String value = ObjectUtils.isEmpty(paramMap.get(key)) ? null : paramMap.get(key).toString();
if (ObjectUtils.isNotEmpty((value))) {
BasicNamevaluePair param1 = new BasicNamevaluePair(key, value);
paramertersList.add(param1);
}
}
uriBuilder.setParameters(paramertersList);
}
// 根据带参数的URI对象构建GET请求对象
HttpGet httpGet = new HttpGet(uriBuilder.build());
if (headMap != null) {
for (Map.Entry entry : headMap.entrySet()) {
if (entry.getValue() != null) {
httpGet.addHeader(entry.getKey(), entry.getValue().toString());
}
}
}
String traceId = MDC.get("traceId");
httpGet.addHeader("traceId", traceId);
httpGet.addHeader("Accept", "*
// 创建请求参数
if (!CollectionUtils.isEmpty(paramMap)) {
List paramertersList = new linkedList<>();
Set keys = paramMap.keySet();
for (String s : keys) {
String key = String.valueOf(s);
String value = ObjectUtils.isEmpty(paramMap.get(key)) ? null : paramMap.get(key).toString();
if (ObjectUtils.isNotEmpty(value)) {
BasicNamevaluePair param1 = new BasicNamevaluePair(key, value);
paramertersList.add(param1);
}
}
// 使用URL实体转换工具
entityParam = new UrlEncodedFormEntity(paramertersList, "UTF-8");
}
httpPost.setEntity(entityParam);
if (headMap != null) {
for (Map.Entry entry : headMap.entrySet()) {
if (entry.getValue() != null) {
httpPost.addHeader(entry.getKey(), entry.getValue().toString());
}
}
}
String traceId = MDC.get("traceId");
httpPost.addHeader("traceId", traceId);
httpPost.addHeader("Accept", "*/*");
httpPost.addHeader("Connection", "Keep-Alive");
httpPost.addHeader("User-Agent", "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.6)");
// 传输的类型
httpPost.addHeader("Content-Type", "application/x-www-form-urlencoded");
// 执行请求
response = httpClient.execute(httpPost);
// 获得响应的实体对象
HttpEntity entity = response.getEntity();
// 使用Apache提供的工具类进行转换成字符串
entityStr = EntityUtils.toString(entity, "UTF-8");
// 此处获取所有的响应头信息并进行打印
System.out.println(Arrays.toString(response.getAllHeaders()));
} catch (ClientProtocolException e) {
System.err.println("Http协议出现问题");
e.printStackTrace();
} catch (ParseException e) {
System.err.println("解析错误");
e.printStackTrace();
} catch (IOException e) {
System.err.println("IO异常");
e.printStackTrace();
} finally {
// 释放连接
if (null != response) {
try {
response.close();
httpClient.close();
} catch (IOException e) {
System.err.println("释放连接出错");
e.printStackTrace();
}
}
}
return entityStr;
}
}
7、请求实例: 1-调用-2
1: 2021-07-21 11:14:30.168 - [283ba7ba-8910-48e3-8864-cd8de7af07cb] INFO com.example.demolog4jmdc.controller.TestController:27 - 测试 test1 2021-07-21 11:14:30.169 - [283ba7ba-8910-48e3-8864-cd8de7af07cb] INFO com.example.demolog4jmdc.controller.TestService:18 - =====TestService.test1 2021-07-21 11:14:30.169 - [283ba7ba-8910-48e3-8864-cd8de7af07cb] INFO com.example.demolog4jmdc.controller.TestService:22 - =====TestService.test3 2021-07-21 11:14:30.169 - [283ba7ba-8910-48e3-8864-cd8de7af07cb] INFO com.example.demolog4jmdc.controller.TestService:26 - =====TestService.test3 2021-07-21 11:14:30.771 - [283ba7ba-8910-48e3-8864-cd8de7af07cb] INFO com.example.demolog4jmdc.controller.TestController:35 - ===s===aaaaa 2: 2021-07-21 11:14:30.746 - [283ba7ba-8910-48e3-8864-cd8de7af07cb] INFO com.example.demolog4jmdc2.controller.TestController:26 - 测试 test1-traceId:283ba7ba-8910-48e3-8864-cd8de7af07cb
到此分布式链路追踪—traceId生成与使用（MDC）介绍完成。
