diff --git a/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpDevicePacket.java b/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpDevicePacket.java
index 9a2f71a..d350f60 100644
--- a/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpDevicePacket.java
+++ b/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpDevicePacket.java
@@ -70,13 +70,12 @@ public static UsbIpDevicePacket read(InputStream in) throws IOException {
 	
 	@Override
 	public String toString() {
-		StringBuilder sb = new StringBuilder();
-		sb.append(String.format("Command: 0x%x\n", command));
-		sb.append(String.format("Seq: %d\n", seqNum));
-		sb.append(String.format("Dev ID: 0x%x\n", devId));
-		sb.append(String.format("Direction: %d\n", direction));
-		sb.append(String.format("Endpoint: %d\n", ep));
-		return sb.toString();
+		String sb = String.format("Command: 0x%x\n", command) +
+				String.format("Seq: %d\n", seqNum) +
+				String.format("Dev ID: 0x%x\n", devId) +
+				String.format("Direction: %d\n", direction) +
+				String.format("Endpoint: %d\n", ep);
+		return sb;
 	}
 	
 	public byte[] serialize() {
diff --git a/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpSubmitUrb.java b/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpSubmitUrb.java
index a9d307b..9f65a0f 100644
--- a/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpSubmitUrb.java
+++ b/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpSubmitUrb.java
@@ -56,14 +56,13 @@ public static UsbIpSubmitUrb read(byte[] header, InputStream in) throws IOExcept
 	
 	@Override
 	public String toString() {
-		StringBuilder sb = new StringBuilder();
-		sb.append(super.toString());
-		sb.append(String.format("Xfer flags: 0x%x\n", transferFlags));
-		sb.append(String.format("Xfer length: %d\n", transferBufferLength));
-		sb.append(String.format("Start frame: %d\n", startFrame));
-		sb.append(String.format("Number Of Packets: %d\n", numberOfPackets));
-		sb.append(String.format("Interval: %d\n", interval));
-		return sb.toString();
+		String sb = super.toString() +
+				String.format("Xfer flags: 0x%x\n", transferFlags) +
+				String.format("Xfer length: %d\n", transferBufferLength) +
+				String.format("Start frame: %d\n", startFrame) +
+				String.format("Number Of Packets: %d\n", numberOfPackets) +
+				String.format("Interval: %d\n", interval);
+		return sb;
 	}
 
 	@Override
diff --git a/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpSubmitUrbReply.java b/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpSubmitUrbReply.java
index 25621ca..7c57bae 100644
--- a/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpSubmitUrbReply.java
+++ b/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpSubmitUrbReply.java
@@ -38,13 +38,12 @@ protected byte[] serializeInternal() {
 	
 	@Override
 	public String toString() {
-		StringBuilder sb = new StringBuilder();
-		sb.append(super.toString());
-		sb.append(String.format("Status: 0x%x\n", status));
-		sb.append(String.format("Actual length: %d\n", actualLength));
-		sb.append(String.format("Start frame: %d\n", startFrame));
-		sb.append(String.format("Number Of Packets: %d\n", numberOfPackets));
-		sb.append(String.format("Error Count: %d\n", errorCount));
-		return sb.toString();
+        String sb = super.toString() +
+                String.format("Status: 0x%x\n", status) +
+                String.format("Actual length: %d\n", actualLength) +
+                String.format("Start frame: %d\n", startFrame) +
+                String.format("Number Of Packets: %d\n", numberOfPackets) +
+                String.format("Error Count: %d\n", errorCount);
+		return sb;
 	}
 }
diff --git a/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpUnlinkUrb.java b/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpUnlinkUrb.java
index cfa61ef..5e82b8a 100644
--- a/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpUnlinkUrb.java
+++ b/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpUnlinkUrb.java
@@ -35,10 +35,9 @@ public static UsbIpUnlinkUrb read(byte[] header, InputStream in) throws IOExcept
 	
 	@Override
 	public String toString() {
-		StringBuilder sb = new StringBuilder();
-		sb.append(super.toString());
-		sb.append(String.format("Sequence number to unlink: %d\n", seqNumToUnlink));
-		return sb.toString();
+        String sb = super.toString() +
+                String.format("Sequence number to unlink: %d\n", seqNumToUnlink);
+		return sb;
 	}
 
 	@Override
diff --git a/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpUnlinkUrbReply.java b/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpUnlinkUrbReply.java
index adc3bd7..cf57c4f 100644
--- a/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpUnlinkUrbReply.java
+++ b/app/src/main/java/org/cgutman/usbip/server/protocol/dev/UsbIpUnlinkUrbReply.java
@@ -20,9 +20,8 @@ protected byte[] serializeInternal() {
 	
 	@Override
 	public String toString() {
-		StringBuilder sb = new StringBuilder();
-		sb.append(super.toString());
-		sb.append(String.format("Status: 0x%x\n", status));
-		return sb.toString();
+        String sb = super.toString() +
+                String.format("Status: 0x%x\n", status);
+		return sb;
 	}
 }
diff --git a/app/src/main/java/org/cgutman/usbip/service/UsbIpService.java b/app/src/main/java/org/cgutman/usbip/service/UsbIpService.java
index 8de8764..99f4b71 100644
--- a/app/src/main/java/org/cgutman/usbip/service/UsbIpService.java
+++ b/app/src/main/java/org/cgutman/usbip/service/UsbIpService.java
@@ -30,7 +30,6 @@
 import org.cgutman.usbipserverforandroid.R;
 
 import android.annotation.SuppressLint;
-import android.app.Notification;
 import android.app.NotificationChannel;
 import android.app.NotificationManager;
 import android.app.PendingIntent;
@@ -819,7 +818,7 @@ public void abortUrbRequest(Socket s, UsbIpUnlinkUrb msg) {
 					-22); // EINVAL
 	}
 	
-	class AttachedDeviceContext {
+	static class AttachedDeviceContext {
 		public UsbDevice device;
 		public UsbDeviceConnection devConn;
 		public ThreadPoolExecutor requestPool;
diff --git a/app/src/main/res/layout/activity_usbip_config.xml b/app/src/main/res/layout/activity_usbip_config.xml
index fb7e800..92eea4a 100644
--- a/app/src/main/res/layout/activity_usbip_config.xml
+++ b/app/src/main/res/layout/activity_usbip_config.xml
@@ -1,11 +1,10 @@
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent"
     android:paddingBottom="@dimen/activity_vertical_margin"
     android:paddingLeft="@dimen/activity_horizontal_margin"
     android:paddingRight="@dimen/activity_horizontal_margin"
-    android:paddingTop="@dimen/activity_vertical_margin" >
+    android:paddingTop="@dimen/activity_vertical_margin">
 
     <TextView
         android:id="@+id/serviceStatus"
diff --git a/app/src/main/res/values/styles.xml b/app/src/main/res/values/styles.xml
index d8ec7fe..5261612 100644
--- a/app/src/main/res/values/styles.xml
+++ b/app/src/main/res/values/styles.xml
@@ -6,7 +6,7 @@
         by AppBaseTheme from res/values-vXX/styles.xml on newer devices.
 
     -->
-    <style name="AppBaseTheme" parent="android:Theme"></style>
+    <style name="AppBaseTheme" parent="android:Theme" />
 
     <!-- Application theme. -->
     <style name="AppTheme" parent="AppBaseTheme">