[PR #1] improving logging

src/main/java/com/datadoghq/trace/impl/DDSpan.java

@@ -97,7 +97,7 @@ public class DDSpan implements io.opentracing.Span {
      * @see io.opentracing.Span#finish(long)
      */
     public void finish(long stoptimeMicros) {
-        this.durationNano = TimeUnit.MICROSECONDS.toNanos(stoptimeMicros- this.startTimeMicro);
+        this.durationNano = TimeUnit.MICROSECONDS.toNanos(stoptimeMicros - this.startTimeMicro);
         afterFinish();
     }
 
@@ -173,22 +173,6 @@ public class DDSpan implements io.opentracing.Span {
         return this;
     }
 
-    public Span log(Map<String, ?> map) {
-        return null;
-    }
-
-    public Span log(long l, Map<String, ?> map) {
-        return null;
-    }
-
-    public Span log(String s) {
-        return null;
-    }
-
-    public Span log(long l, String s) {
-        return null;
-    }
-
     /* (non-Javadoc)
      * @see io.opentracing.Span#context()
      */
@@ -223,6 +207,38 @@ public class DDSpan implements io.opentracing.Span {
         return this;
     }
 
+    /* (non-Javadoc)
+     * @see io.opentracing.Span#log(java.lang.String, java.lang.Object)
+     */
+    public Span log(Map<String, ?> map) {
+        logger.debug("`log` method is not implemented. Doing nothing");
+        return this;
+    }
+
+    /* (non-Javadoc)
+     * @see io.opentracing.Span#log(java.lang.String, java.lang.Object)
+     */
+    public Span log(long l, Map<String, ?> map) {
+        logger.debug("`log` method is not implemented. Doing nothing");
+        return this;
+    }
+
+    /* (non-Javadoc)
+     * @see io.opentracing.Span#log(java.lang.String, java.lang.Object)
+     */
+    public Span log(String s) {
+        logger.debug("`log` method is not implemented. Doing nothing");
+        return this;
+    }
+
+    /* (non-Javadoc)
+     * @see io.opentracing.Span#log(java.lang.String, java.lang.Object)
+     */
+    public Span log(long l, String s) {
+        logger.debug("`log` method is not implemented. Doing nothing");
+        return this;
+    }
+
     /* (non-Javadoc)
      * @see io.opentracing.Span#log(java.lang.String, java.lang.Object)
      */

src/main/java/com/datadoghq/trace/impl/DDTracer.java

@@ -106,7 +106,7 @@ public class DDTracer implements io.opentracing.Tracer {
             DDSpanContext context = buildSpanContext();
             DDSpan span = new DDSpan(this.operationName, this.tags, this.timestamp, context);
 
-            logger.debug("Starting a new span. " + span.toString());
+            logger.debug("{} - Starting a new span.", span);
 
             return span;
         }
@@ -224,7 +224,7 @@ public class DDTracer implements io.opentracing.Tracer {
                     DDTracer.this
             );
 
-            logger.debug("Building a new span context. " + context.toString());
+            logger.debug("Building a new span context. {}", context);
             return context;
         }
 

src/main/java/com/datadoghq/trace/impl/RateSampler.java

@@ -36,14 +36,14 @@ public class RateSampler implements Sampler {
         }
 
         this.sampleRate = sampleRate;
-        logger.debug("Initializing the RateSampler, sampleRate=" + this.sampleRate * 100 + "%");
+        logger.debug("Initializing the RateSampler, sampleRate: {} %", this.sampleRate * 100);
 
     }
 
     @Override
     public boolean sample(DDSpan span) {
         boolean sample = Math.random() <= this.sampleRate;
-        logger.debug(span + " - Span is sampled: " + sample);
+        logger.debug("{} - Span is sampled: {}", span, sample);
         return sample;
     }
 

src/main/java/com/datadoghq/trace/writer/impl/LoggingWritter.java

@@ -15,7 +15,7 @@ public class LoggingWritter implements Writer{
 	
 	@Override
 	public void write(List<Span> trace) {
-		logger.info("write(trace): "+trace);
+		logger.info("write(trace): {}", trace);
 	}
 
 	@Override