diff --git a/pom.xml b/pom.xml
index 9ede59f..7ab10f6 100644
--- a/pom.xml
+++ b/pom.xml
@@ -44,6 +44,19 @@
           <windowtitle>Engine.IO Client API</windowtitle>
         </configuration>
       </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-plugin</artifactId>
+        <version>2.14.1</version>
+        <configuration>
+          <systemProperties>
+            <property>
+              <name>java.util.logging.config.file</name>
+              <value>./src/test/resources/logging.properties</value>
+            </property>
+          </systemProperties>
+        </configuration>
+      </plugin>
       <plugin>
         <groupId>org.codehaus.mojo</groupId>
         <artifactId>exec-maven-plugin</artifactId>
diff --git a/src/main/java/com/github/nkzawa/engineio/client/Socket.java b/src/main/java/com/github/nkzawa/engineio/client/Socket.java
index 244ff9c..784976f 100644
--- a/src/main/java/com/github/nkzawa/engineio/client/Socket.java
+++ b/src/main/java/com/github/nkzawa/engineio/client/Socket.java
@@ -18,7 +18,7 @@ import java.util.logging.Logger;
 
 public abstract class Socket extends Emitter {
 
-    private static final Logger logger = Logger.getLogger("engine.io-client:socket");
+    private static final Logger logger = Logger.getLogger(Socket.class.getName());
 
     private static final int OPENING = 0;
     private static final int OPEN = 1;
@@ -129,7 +129,7 @@ public abstract class Socket extends Emitter {
     }
 
     private Transport createTransport(String name) {
-        logger.info(String.format("creating transport '%s'", name));
+        logger.fine(String.format("creating transport '%s'", name));
         Map<String, String> query = new HashMap<String, String>(this.query);
 
         query.put("EIO", String.valueOf(Parser.protocol));
@@ -161,7 +161,7 @@ public abstract class Socket extends Emitter {
         final Socket self = this;
 
         if (this.transport != null) {
-            logger.info("clearing existing transport");
+            logger.fine("clearing existing transport");
             this.transport.off();
         }
 
@@ -191,7 +191,7 @@ public abstract class Socket extends Emitter {
     }
 
     private void probe(final String name) {
-        logger.info(String.format("probing transport '%s'", name));
+        logger.fine(String.format("probing transport '%s'", name));
         final Transport[] transport = new Transport[] {this.createTransport(name)};
         final boolean[] failed = new boolean[] {false};
         final Socket self = this;
@@ -210,7 +210,7 @@ public abstract class Socket extends Emitter {
 
                 transport[0].close();
                 transport[0] = null;
-                logger.info(String.format("probing transport '%s' failed because of error: %s", name, err));
+                logger.fine(String.format("probing transport '%s' failed because of error: %s", name, err));
                 self.emit(EVENT_ERROR, error);
             }
         };
@@ -220,7 +220,7 @@ public abstract class Socket extends Emitter {
             public void call(Object... args) {
                 if (failed[0]) return;
 
-                logger.info(String.format("probe transport '%s' opened", name));
+                logger.fine(String.format("probe transport '%s' opened", name));
                 Packet packet = new Packet(Packet.PING, "probe");
                 transport[0].send(new Packet[] {packet});
                 transport[0].once(Transport.EVENT_PACKET, new Listener() {
@@ -229,11 +229,11 @@ public abstract class Socket extends Emitter {
                         if (failed[0]) return;
                         Packet msg = (Packet)args[0];
                         if (Packet.PONG.equals(msg.type) && "probe".equals(msg.data)) {
-                            logger.info(String.format("probe transport '%s' pong", name));
+                            logger.fine(String.format("probe transport '%s' pong", name));
                             self.upgrading = true;
                             self.emit(EVENT_UPGRADING, transport[0]);
 
-                            logger.info(String.format("pausing current transport '%s'", self.transport.name));
+                            logger.fine(String.format("pausing current transport '%s'", self.transport.name));
                             ((Polling)self.transport).pause(new Runnable() {
                                 @Override
                                 public void run() {
@@ -242,7 +242,7 @@ public abstract class Socket extends Emitter {
                                         return;
                                     }
 
-                                    logger.info("changing transport and sending upgrade packet");
+                                    logger.fine("changing transport and sending upgrade packet");
                                     transport[0].off(Transport.EVENT_ERROR, onerror);
                                     self.emit(EVENT_UPGRADE, transport);
                                     self.setTransport(transport[0]);
@@ -254,7 +254,7 @@ public abstract class Socket extends Emitter {
                                 }
                             });
                         } else {
-                            logger.info(String.format("probe transport '%s' failed", name));
+                            logger.fine(String.format("probe transport '%s' failed", name));
                             EngineIOException err = new EngineIOException("probe error");
                             //err.transport = transport[0].name;
                             self.emit(EVENT_ERROR, err);
@@ -270,7 +270,7 @@ public abstract class Socket extends Emitter {
             @Override
             public void call(Object... args) {
                 if (transport[0] != null) {
-                    logger.info("socket closed prematurely - aborting probe");
+                    logger.fine("socket closed prematurely - aborting probe");
                     failed[0] = true;
                     transport[0].close();
                     transport[0] = null;
@@ -283,7 +283,7 @@ public abstract class Socket extends Emitter {
             public void call(Object... args) {
                 Transport to = (Transport)args[0];
                 if (transport[0] != null && !to.name.equals(transport[0].name)) {
-                    logger.info(String.format("'%s' works - aborting '%s'", to.name, transport[0].name));
+                    logger.fine(String.format("'%s' works - aborting '%s'", to.name, transport[0].name));
                     transport[0].close();
                     transport[0] = null;
                 }
@@ -294,14 +294,14 @@ public abstract class Socket extends Emitter {
     }
 
     private void onOpen() {
-        logger.info("socket open");
+        logger.fine("socket open");
         this.readyState = OPEN;
         this.emit(EVENT_OPEN);
         this.onopen();
         this.flush();
 
         if (this.readyState == OPEN && this.upgrade && this.transport instanceof Polling) {
-            logger.info("starting upgrade probes");
+            logger.fine("starting upgrade probes");
             for (String upgrade: this.upgrades) {
                 this.probe(upgrade);
             }
@@ -310,7 +310,7 @@ public abstract class Socket extends Emitter {
 
     private void onPacket(Packet packet) {
         if (this.readyState == OPENING || this.readyState == OPEN) {
-            logger.info(String.format("socket received: type '%s', data '%s'", packet.type, packet.data));
+            logger.fine(String.format("socket received: type '%s', data '%s'", packet.type, packet.data));
 
             this.emit(EVENT_PACKET, packet);
             this.emit(EVENT_HEARTBEAT);
@@ -330,7 +330,7 @@ public abstract class Socket extends Emitter {
                 this.onmessage(packet.data);
             }
         } else {
-            logger.info(String.format("packet received with socket readyState '%s'", STATE_MAP.get(this.readyState)));
+            logger.fine(String.format("packet received with socket readyState '%s'", STATE_MAP.get(this.readyState)));
         }
     }
 
@@ -389,7 +389,7 @@ public abstract class Socket extends Emitter {
         this.pingIntervalTimer = this.heartbeatScheduler.schedule(new Runnable() {
             @Override
             public void run() {
-                logger.info(String.format("writing ping packet - expecting pong within %sms", self.pingTimeout));
+                logger.fine(String.format("writing ping packet - expecting pong within %sms", self.pingTimeout));
                 self.sendPacket(Packet.PING);
                 self.onHeartbeat(self.pingTimeout);
             }
@@ -424,7 +424,7 @@ public abstract class Socket extends Emitter {
     private void flush() {
         if (this.readyState != CLOSED && this.transport.writable &&
                 !this.upgrading && this.writeBuffer.size() != 0) {
-            logger.info(String.format("flushing %d packets in socket", this.writeBuffer.size()));
+            logger.fine(String.format("flushing %d packets in socket", this.writeBuffer.size()));
             this.prevBufferLen = this.writeBuffer.size();
             this.transport.send(this.writeBuffer.toArray(new Packet[this.writeBuffer.size()]));
             this.emit(EVENT_FLUSH);
@@ -467,7 +467,7 @@ public abstract class Socket extends Emitter {
     public Socket close() {
         if (this.readyState == OPENING || this.readyState == OPEN) {
             this.onClose("forced close");
-            logger.info("socket closing - telling transport to close");
+            logger.fine("socket closing - telling transport to close");
             this.transport.close();
             this.transport.off();
         }
@@ -476,7 +476,7 @@ public abstract class Socket extends Emitter {
     }
 
     private void onError(Exception err) {
-        logger.info(String.format("socket error %s", err));
+        logger.fine(String.format("socket error %s", err));
         this.emit(EVENT_ERROR, err);
         this.onClose("transport error", err);
     }
@@ -487,7 +487,7 @@ public abstract class Socket extends Emitter {
 
     private void onClose(String reason, Exception desc) {
         if (this.readyState == OPENING || this.readyState == OPEN) {
-            logger.info(String.format("socket close with reason: %s", reason));
+            logger.fine(String.format("socket close with reason: %s", reason));
             if (this.pingIntervalTimer != null) {
                 this.pingIntervalTimer.cancel(true);
             }
diff --git a/src/main/java/com/github/nkzawa/engineio/client/transports/Polling.java b/src/main/java/com/github/nkzawa/engineio/client/transports/Polling.java
index 82694dc..27bbde7 100644
--- a/src/main/java/com/github/nkzawa/engineio/client/transports/Polling.java
+++ b/src/main/java/com/github/nkzawa/engineio/client/transports/Polling.java
@@ -13,7 +13,7 @@ import java.util.logging.Logger;
 
 abstract public class Polling extends Transport {
 
-    private static final Logger logger = Logger.getLogger("engine.io-client:polling");
+    private static final Logger logger = Logger.getLogger(Polling.class.getName());
 
     public static final String NAME = "polling";
 
@@ -41,7 +41,7 @@ abstract public class Polling extends Transport {
         final Runnable pause = new Runnable() {
             @Override
             public void run() {
-                logger.info("paused");
+                logger.fine("paused");
                 self.readyState = PAUSED;
                 onPause.run();
             }
@@ -51,12 +51,12 @@ abstract public class Polling extends Transport {
             final int[] total = new int[] {0};
 
             if (this.polling) {
-                logger.info("we are currently polling - waiting to pause");
+                logger.fine("we are currently polling - waiting to pause");
                 total[0]++;
                 this.once(EVENT_POLL_COMPLETE, new Listener() {
                     @Override
                     public void call(Object... args) {
-                        logger.info("pre-pause polling complete");
+                        logger.fine("pre-pause polling complete");
                         if (--total[0] == 0) {
                             pause.run();
                         }
@@ -65,12 +65,12 @@ abstract public class Polling extends Transport {
             }
 
             if (!this.writable) {
-                logger.info("we are currently writing - waiting to pause");
+                logger.fine("we are currently writing - waiting to pause");
                 total[0]++;
                 this.once(EVENT_DRAIN, new Listener() {
                     @Override
                     public void call(Object... args) {
-                        logger.info("pre-pause writing complete");
+                        logger.fine("pre-pause writing complete");
                         if (--total[0] == 0) {
                             pause.run();
                         }
@@ -83,7 +83,7 @@ abstract public class Polling extends Transport {
     }
 
     private void poll() {
-        logger.info("polling");
+        logger.fine("polling");
         this.polling = true;
         this.doPoll();
         this.emit(EVENT_POLL);
@@ -91,7 +91,7 @@ abstract public class Polling extends Transport {
 
     protected void onData(String data) {
         final Polling self = this;
-        logger.info(String.format("polling got data %s", data));
+        logger.fine(String.format("polling got data %s", data));
 
         Parser.decodePayload(data, new Parser.DecodePayloadCallback() {
             @Override
@@ -117,13 +117,13 @@ abstract public class Polling extends Transport {
             if (this.readyState == OPEN) {
                 this.poll();
             } else {
-                logger.info(String.format("ignoring poll - transport state '%s'", STATE_MAP.get(this.readyState)));
+                logger.fine(String.format("ignoring poll - transport state '%s'", STATE_MAP.get(this.readyState)));
             }
         }
     }
 
     protected void doClose() {
-        logger.info("sending close packet");
+        logger.fine("sending close packet");
         this.send(new Packet[] {new Packet(Packet.CLOSE, null)});
     }
 
@@ -162,9 +162,7 @@ abstract public class Polling extends Transport {
             _query = "?" + _query;
         }
 
-        return new StringBuilder()
-                .append(schema).append("://").append(this.hostname)
-                .append(port).append(this.path).append(_query).toString();
+        return schema + "://" + this.hostname + port + this.path + _query;
     }
 
     abstract protected void doWrite(String data, Runnable fn);
diff --git a/src/main/java/com/github/nkzawa/engineio/client/transports/PollingXHR.java b/src/main/java/com/github/nkzawa/engineio/client/transports/PollingXHR.java
index 2845e71..7515e16 100644
--- a/src/main/java/com/github/nkzawa/engineio/client/transports/PollingXHR.java
+++ b/src/main/java/com/github/nkzawa/engineio/client/transports/PollingXHR.java
@@ -12,7 +12,7 @@ import java.util.logging.Logger;
 
 public class PollingXHR extends Polling {
 
-    private static final Logger logger = Logger.getLogger("engine.io-client:polling-xhr");
+    private static final Logger logger = Logger.getLogger(PollingXHR.class.getName());
 
     private Request sendXhr;
     private Request pollXhr;
@@ -57,7 +57,7 @@ public class PollingXHR extends Polling {
     }
 
     protected void doPoll() {
-        logger.info("xhr poll");
+        logger.fine("xhr poll");
         Request req = this.request();
         final PollingXHR self = this;
         req.on(Request.EVENT_DATA, new Listener() {
@@ -113,7 +113,7 @@ public class PollingXHR extends Polling {
                 xhr.setRequestProperty("Content-type", "text/plain;charset=UTF-8");
             }
 
-            logger.info(String.format("sending xhr with url %s | data %s", this.uri, this.data));
+            logger.fine(String.format("sending xhr with url %s | data %s", this.uri, this.data));
             xhrService.submit(new Runnable() {
                 @Override
                 public void run() {
diff --git a/src/main/java/com/github/nkzawa/engineio/client/transports/WebSocket.java b/src/main/java/com/github/nkzawa/engineio/client/transports/WebSocket.java
index 7a509ca..684fc25 100644
--- a/src/main/java/com/github/nkzawa/engineio/client/transports/WebSocket.java
+++ b/src/main/java/com/github/nkzawa/engineio/client/transports/WebSocket.java
@@ -131,9 +131,7 @@ public class WebSocket extends Transport {
             _query = "?" + _query;
         }
 
-        return new StringBuilder()
-                .append(schema).append("://").append(this.hostname)
-                .append(port).append(this.path).append(_query).toString();
+        return schema + "://" + this.hostname + port + this.path + _query;
     }
 
     private boolean check() {
diff --git a/src/test/resources/logging.properties b/src/test/resources/logging.properties
new file mode 100644
index 0000000..b1a5c7d
--- /dev/null
+++ b/src/test/resources/logging.properties
@@ -0,0 +1,8 @@
+handlers = java.util.logging.ConsoleHandler, java.util.logging.FileHandler
+.level = ALL
+
+java.util.logging.ConsoleHandler.level = FINE
+
+java.util.logging.FileHandler.level = ALL
+java.util.logging.FileHandler.pattern = ./target/test.log
+java.util.logging.FileHandler.formatter = java.util.logging.SimpleFormatter