击上方蓝色“程序员白楠楠”，选择“设为星标”

作者：松下听泉

出处：https://blog.csdn.net/weixin_39427718

1.新建项目

利用idea创建一个父项目，三个子项目，其中一个项目为生产者，一个项目为消费者，一个为接口等公共服务项目，生产者和消费者需要有web依赖，可以作为tomcat容器启动。

2.项目依赖

  <dependencies><dependency><groupId>org.apache.dubbo</groupId><artifactId>dubbo-spring-boot-starter</artifactId><version>2.7.6</version></dependency>

<!-- zk的依赖 --><dependency><groupId>org.apache.dubbo</groupId><artifactId>dubbo-dependencies-zookeeper</artifactId><version>2.7.6</version><type>pom</type><exclusions><exclusion><groupId>org.slf4j</groupId><artifactId>slf4j-log4j12</artifactId></exclusion></exclusions></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-aop</artifactId><scope>test</scope></dependency><dependency><groupId>org.aspectj</groupId><artifactId>aspectjweaver</artifactId></dependency>

3.在facade项目中新建接口

4.编写生产者

4.1 增加dubbo配置

server.port=8081dubbo.registry.address=zookeeper://localhost:2181dubbo.protocol.name=dubbodubbo.protocol.port=20880dubbo.registry.timeout=30000dubbo.application.name=dubbo-provider-ll

4.2 编写生产者dubbo filter

public class ProviderFilter implements Filter {@Overridepublic Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {        Object threadName= invocation.getAttachment("ThreadName");if(null!=threadName){            Thread thread = Thread.currentThread();            thread.setName(threadName.toString());}return invoker.invoke(invocation);}}

注意：此处Filter 是dubbo的filter，不是servlet的filter

这里代码的目的是将从消费端传来的线程名称设置为线程名称

在resources目录下新建META-INF/dubbo/com.alibaba.dubbo.rpc.Filter 文件
即新增目录META-INF/dubbo和文件 com.alibaba.dubbo.rpc.Filter

在文件中增加，等号后面为实现dubbo filter的实现类路径providerFilter=com.dubbo.spring.provider.filter.ProviderFilter

4.3编写dubbo生产者实现类

@Service(filter = {"providerFilter"})public class DemoServiceImpl implements IDemoService {public Logger LOGGER= LoggerFactory.getLogger(DemoServiceImpl.class);@Overridepublic String getName() {        LOGGER.info("provider ThreadName : "+Thread.currentThread().getName());return "dubbo-test";}}

5.编写消费者

5.1编写消费者filter

public class DubboFilter implements Filter {@Overridepublic Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {        String name = Thread.currentThread().getName();        invocation.setAttachment("ThreadName",name);return  invoker.invoke(invocation);}}

此处是将线程名称放入到attachment中，attachment底层是hashmap，后续使用dubbo请求生产者时，会把attachment给到生产者，故在生产中中可以通过key ThreadName来获取消费者端的线程名称在resources目录下新建META-INF/dubbo/com.alibaba.dubbo.rpc.Filter 文件
即新增目录META-INF/dubbo和文件 com.alibaba.dubbo.rpc.Filter

在文件中增加，等号后面为实现dubbo filter的实现类路径consumerFilter=com.dubbo.spring.consumer.filter.DubboFilter

5.2 编写response对象

public class Response implements Serializable {

private static final long serialVersionUID = -3186818832535757509L;private String code;

private String message;

private Object result;

private String index;

public String getCode() {return code;}

public void setCode(String code) {this.code = code;}

public String getMessage() {return message;}

public void setMessage(String message) {this.message = message;}

public Object getResult() {return result;}

public void setResult(Object result) {this.result = result;}

public String getIndex() {return index;}

public void setIndex(String index) {this.index = index;}}

此response为web端返回到页面统一对象

5.3 编写aop切面

@Aspect@Componentpublic class AopContext {

@Before("execution(* com.dubbo.spring..*.*(..))")public void before(){        Thread thread = Thread.currentThread();        thread.setName(UUIDUtil.getUUID());}@Around("execution(* com.dubbo.spring..*.*(..))")public Object around(ProceedingJoinPoint pjp){        Response response=new Response();try {            Object proceed = pjp.proceed();if(proceed instanceof Response){                 response=(Response) proceed;                response.setIndex(Thread.currentThread().getName());}} catch (Throwable throwable) {            throwable.printStackTrace();}return response;}}

1.before是在请求进入时给线程设置名称，为随机生成的uuid
2.around是环绕通知，在执行完之后，在返回的结果中将线程名称设置进去，便于以后异常追踪

5.4 编写web

@RestControllerpublic class WebController {

private Logger LOGGER= LoggerFactory.getLogger(WebController.class);

@Reference(filter = {"consumerFilter"})private IDemoService iDemoService;

@GetMapping("/getName")public Response getName(){        LOGGER.info("consumer ThreadName : "+Thread.currentThread().getName());        String name = iDemoService.getName();        Response response=new Response();        response.setResult(name);        response.setCode("1001");        response.setMessage("success");return response;}}

请求结果

此处为postman响应的，index 为1ca55cb7a17148879923265b89102ccf

生产者线程名称：
消费者线程名称：可以看到从web页面到生产者，消费者，都有一个全局唯一id进行贯穿，如果在web页面提示有异常时，可以通过这个uuid进行日志追踪