Merge pull request #50 from felixbarny/set-operation-name

Add Span#setOperationName

opentracing-api/src/main/java/io/opentracing/Span.java

@@ -104,4 +104,11 @@ public interface Span extends AutoCloseable {
      * @return the value of the baggage item identified by the given key, or null if no such item could be found
      */
     String getBaggageItem(String key);
+
+    /**
+     * Sets the string name for the logical operation this span represents.
+     *
+     * @return this Span instance, for chaining
+     */
+    Span setOperationName(String operationName);
 }

opentracing-api/src/main/java/io/opentracing/Tracer.java

@@ -23,6 +23,8 @@ public interface Tracer {
   /**
    * Return a new SpanBuilder for a Span with the given `operationName`.
    *
+   * <p>You can override the operationName later via {@link Span#setOperationName(String)}.
+   *
    * <p>A contrived example:
    * <pre>{@code
     Tracer tracer = ...

opentracing-impl-java8/src/main/java/io/opentracing/AbstractSpan.java

@@ -23,7 +23,7 @@
 
 abstract class AbstractSpan implements Span, SpanContext {
 
-    final String operationName;
+    String operationName;
 
     protected final Map<String,String> baggage = new HashMap<>();
 
@@ -114,15 +114,21 @@ public final Span log(long instantMicroseconds, String message, /* @Nullable */
         return this;
     }
 
+    @Override
+    public Span setOperationName(String operationName) {
+        this.operationName = operationName;
+        return this;
+    }
+
     final class LogData {
-            private final Instant time;
-            private final String message;
-            private final Object payload;
-
-            LogData(Instant time, String message, Object payload) {
-                this.time = time;
-                this.message = message;
-                this.payload = payload;
-            }
+        private final Instant time;
+        private final String message;
+        private final Object payload;
+
+        LogData(Instant time, String message, Object payload) {
+            this.time = time;
+            this.message = message;
+            this.payload = payload;
         }
+    }
 }

opentracing-impl/src/main/java/io/opentracing/NoopSpan.java

@@ -74,4 +74,9 @@ public Span log(long timestampMicroseconds, String eventName, Object payload) {
     @Override
     public String getBaggageItem(String key) { return null; }
 
+    @Override
+    public Span setOperationName(String operationName) {
+        return this;
+    }
+
 }

opentracing-mock/src/main/java/io/opentracing/mock/MockSpan.java

@@ -13,15 +13,15 @@
  */
 package io.opentracing.mock;
 
-import io.opentracing.Span;
-import io.opentracing.SpanContext;
-
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicLong;
 
+import io.opentracing.Span;
+import io.opentracing.SpanContext;
+
 /**
  * MockSpans are created via MockTracer.buildSpan(...), but they are also returned via calls to
  * MockTracer.finishedSpans(). They provide accessors to all Span state.
@@ -39,11 +39,18 @@ public final class MockSpan implements Span {
     private long finishMicros;
     private final Map<String, Object> tags;
     private final List<LogEntry> logEntries = new ArrayList<>();
-    private final String operationName;
+    private String operationName;
 
     public String operationName() {
         return this.operationName;
     }
+
+    @Override
+    public Span setOperationName(String operationName) {
+        this.operationName = operationName;
+        return this;
+    }
+
     /**
      * TODO: Support multiple parents in this API.
      *