[DEMO] Core Tracer API adoption for service-a

README.md

@@ -66,7 +66,25 @@ If you only need Jaeger Tracer, just add :
 @ComponentScan(basePackages = {"com.github.frtu.logs.tracing.core", "..."})
 ```
 
-See [sample-microservices/service-a](https://github.com/frtu/log-platform/tree/master/sample-microservices/service-a)
+You can create a single Span structure :
+
+```
+Span span = tracer.buildSpan("say-hello1").start();
+LOGGER.info("hello1");
+span.finish();
+```
+
+OR a node from a graph using Scope :
+
+```
+try (Scope scope = tracer.buildSpan("say-hello2").startActive(true)) {
+	LOGGER.info("hello2");
+}
+```
+
+
+* See [sample-microservices/service-a](https://github.com/frtu/log-platform/tree/master/sample-microservices/service-a)
+* Or more at [opentracing.io - span](https://opentracing.io/docs/overview/spans/)
 
 ###### b) @ExecutionSpan AOP
 

sample-microservices/service-a/src/main/java/com/github/frtu/logs/example/demo/DemoApplication.java

@@ -5,7 +5,7 @@
 import org.springframework.context.annotation.ComponentScan;
 
 @SpringBootApplication
-@ComponentScan(basePackages = {"com.github.frtu.logs.example.demo"})
+@ComponentScan(basePackages = {"com.github.frtu.logs.tracing.core", "com.github.frtu.logs.example.demo"})
 public class DemoApplication {
     public static void main(String[] args) {
         SpringApplication.run(DemoApplication.class, args);

sample-microservices/service-a/src/main/java/com/github/frtu/logs/example/demo/ResourceController.java

@@ -1,7 +1,12 @@
 package com.github.frtu.logs.example.demo;
 
+import com.google.common.collect.ImmutableMap;
+import io.opentracing.Scope;
+import io.opentracing.Span;
+import io.opentracing.Tracer;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Controller;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestParam;
@@ -15,23 +20,41 @@
 public class ResourceController {
     private static final Logger LOGGER = LoggerFactory.getLogger(ResourceController.class);
 
+    @Autowired
+    private Tracer tracer;
+
     @RequestMapping("/")
     @ResponseBody
     String home(@RequestParam(value = "service", defaultValue = "ServiceA", required = false) String name) {
+        Span span = tracer.buildSpan("say-hello1").start();
+        LOGGER.info("service={}", name);
+        span.finish();
+
+        try (Scope scope = tracer.buildSpan("say-hello2").startActive(true)) {
+            scope.span().log(ImmutableMap.of("event", "string-format", "value", name));
+            scope.span().setTag("hello-to", name);
+
             String formatString = formatString(name);
             printHello(formatString);
 
             return formatString;
+        }
     }
 
     private String formatString(String helloTo) {
+        try (Scope scope = tracer.buildSpan("formatString").startActive(true)) {
             String helloStr = String.format("Hello, %s!", helloTo);
             printHello(helloStr);
 
+            scope.span().log(ImmutableMap.of("event", "string-format", "value", helloStr));
             return helloStr;
+        }
     }
 
     private void printHello(String helloStr) {
+        try (Scope scope = tracer.buildSpan("printHello").startActive(true)) {
             LOGGER.info(helloStr);
+            scope.span().log(ImmutableMap.of("event", "println"));
+        }
     }
 }