adding a logger conf

pom.xml

@@ -13,13 +13,28 @@
             <artifactId>opentracing-api</artifactId>
             <version>0.21.0</version>
         </dependency>
-		
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>
             <version>2.8.8</version>
         </dependency>
 
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-api</artifactId>
+            <version>1.7.25</version>
+        </dependency>
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <version>1.2.3</version>
+        </dependency>
+        <dependency>
+            <groupId>net.logstash.logback</groupId>
+            <artifactId>logstash-logback-encoder</artifactId>
+            <version>4.9</version>
+        </dependency>
+
         <!-- Testing dependencies -->
         <dependency>
             <groupId>junit</groupId>

src/main/java/com/datadoghq/trace/Utils/TracerLogger.java

@@ -0,0 +1,19 @@
+package com.datadoghq.trace.Utils;
+
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class TracerLogger {
+
+    private Logger logger = LoggerFactory.getLogger("com.datadoghq.trace");
+
+    private final String startNewSpan = "Starting new span - %s [%s]";
+
+    public void startNewSpan(String operationName, long spanId) {
+
+        if (!logger.isTraceEnabled()) return;
+        logger.trace(String.format(startNewSpan, operationName, String.valueOf(spanId)));
+    }
+
+}

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

@@ -1,16 +1,17 @@
 package com.datadoghq.trace.impl;
 
-import io.opentracing.References;
+import com.datadoghq.trace.Utils.TracerLogger;
 import io.opentracing.Span;
 import io.opentracing.SpanContext;
 import io.opentracing.propagation.Format;
-import sun.reflect.generics.reflectiveObjects.NotImplementedException;
 
 import java.util.*;
 
 
 public class Tracer implements io.opentracing.Tracer {
 
+    private TracerLogger logger = new TracerLogger();
+
     public SpanBuilder buildSpan(String operationName) {
         return new SpanBuilder(operationName);
     }
@@ -99,6 +100,7 @@ public class Tracer implements io.opentracing.Tracer {
 
             // build the context
             DDSpanContext context = buildTheSpanContext();
+            logger.startNewSpan(this.operationName, context.getSpanId());
 
             return new DDSpan(
                     Tracer.this,

src/main/resources/logback.xml

@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+
+
+    <property name="log_directory" value="logs/"/>
+
+    <appender name="console" class="ch.qos.logback.core.ConsoleAppender">
+        <layout class="ch.qos.logback.classic.PatternLayout">
+            <Pattern>
+                %d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{36} - %msg%n
+            </Pattern>
+        </layout>
+    </appender>
+
+    <appender name="file-json" class="ch.qos.logback.core.rolling.RollingFileAppender">
+        <file>${log_directory}/dd-tracer-json.log</file>
+        <encoder class="net.logstash.logback.encoder.LogstashEncoder"/>
+        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
+            <fileNamePattern>
+                ${log_directory}/dd-tracer-json.%d{yyyy-MM-dd}.%i.log
+            </fileNamePattern>
+            <timeBasedFileNamingAndTriggeringPolicy
+                    class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
+                <maxFileSize>10MB</maxFileSize>
+            </timeBasedFileNamingAndTriggeringPolicy>
+        </rollingPolicy>
+    </appender>
+
+    <appender name="console-json" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder class="net.logstash.logback.encoder.LogstashEncoder"/>
+    </appender>
+
+    <logger name="com.datadoghq.trace" level="trace">
+        <appender-ref ref="console"/>
+        <appender-ref ref="file-json"/>
+    </logger>
+
+    <root level="info">
+        <appender-ref ref="console"/>
+    </root>
+
+</configuration>

src/test/java/Example.java

@@ -1,6 +1,4 @@
-package com.datadoghq.trace;
+import com.datadoghq.trace.Writer;
-
-
 import com.datadoghq.trace.impl.Tracer;
 import com.datadoghq.trace.writer.impl.DDAgentWriter;
 import io.opentracing.Span;