skywalking-java/docs/en/Application-toolkit-trace.md

• Dependency the toolkit, such as using maven or gradle

   <dependency>
      <groupId>org.apache.skywalking</groupId>
      <artifactId>apm-toolkit-trace</artifactId>
      <version>${skywalking.version}</version>
   </dependency>

• Use TraceContext.traceId() API to obtain traceId.

import TraceContext;
...

modelAndView.addObject("traceId", TraceContext.traceId());

Sample codes only

• Add @Trace to any method you want to trace. After that, you can see the span in the Stack.
• Add custom tag in the context of traced method .

ActiveSpan.tag("my_tag", "my_value");