diff --git a/source/src/main/java/ch/threema/apitool/APIConnector.java b/source/src/main/java/ch/threema/apitool/APIConnector.java
index a310191..8e075ce 100644
--- a/source/src/main/java/ch/threema/apitool/APIConnector.java
+++ b/source/src/main/java/ch/threema/apitool/APIConnector.java
@@ -249,6 +249,7 @@ public UploadResult uploadFile(EncryptResult fileEncryptionResult) throws  IOExc
 		request.write(fileEncryptionResult.getResult());
 		request.writeBytes(crlf);
 		request.writeBytes(twoHyphens + boundary + twoHyphens + crlf);
+		request.close();
 
 		String response = null;
 		int responseCode = connection.getResponseCode();
diff --git a/source/src/main/java/ch/threema/apitool/ConsoleMain.java b/source/src/main/java/ch/threema/apitool/ConsoleMain.java
index 469e815..b5c0887 100644
--- a/source/src/main/java/ch/threema/apitool/ConsoleMain.java
+++ b/source/src/main/java/ch/threema/apitool/ConsoleMain.java
@@ -110,7 +110,7 @@ static class ArgumentCommand {
 
 		public void run(String[] givenArguments) throws Exception {
 			if(givenArguments.length < this.arguments.length) {
-				throw new Exception("invalid arguments");
+				throw new IllegalArgumentException("invalid arguments");
 			}
 
 			this.command.run((String[]) ArrayUtils.subarray(givenArguments, this.arguments.length, givenArguments.length));
diff --git a/source/src/main/java/ch/threema/apitool/console/commands/Command.java b/source/src/main/java/ch/threema/apitool/console/commands/Command.java
index f8e136f..594581c 100644
--- a/source/src/main/java/ch/threema/apitool/console/commands/Command.java
+++ b/source/src/main/java/ch/threema/apitool/console/commands/Command.java
@@ -32,7 +32,7 @@
 import java.util.LinkedList;
 import java.util.List;
 
-abstract public class Command {
+public abstract class Command {
 	private final List<Field> fields = new LinkedList<>();
 	private final String subject;
 	private final String description;
diff --git a/source/src/main/java/ch/threema/apitool/console/commands/CreditsCommand.java b/source/src/main/java/ch/threema/apitool/console/commands/CreditsCommand.java
index c4b2171..23075ad 100644
--- a/source/src/main/java/ch/threema/apitool/console/commands/CreditsCommand.java
+++ b/source/src/main/java/ch/threema/apitool/console/commands/CreditsCommand.java
@@ -52,7 +52,7 @@ protected void execute() throws Exception {
 			System.out.println("Remaining credits: " + credits);
 		}
 		else {
-			System.out.println("Error fetching credits");;
+			System.out.println("Error fetching credits");
 		}
 	}
 }
diff --git a/source/src/main/java/ch/threema/apitool/messages/FileMessage.java b/source/src/main/java/ch/threema/apitool/messages/FileMessage.java
index b0eb3d2..bb4c48b 100644
--- a/source/src/main/java/ch/threema/apitool/messages/FileMessage.java
+++ b/source/src/main/java/ch/threema/apitool/messages/FileMessage.java
@@ -35,13 +35,13 @@
  * A file message that can be sent/received with end-to-end encryption via Threema.
  */
 public class FileMessage extends ThreemaMessage {
-	private final static String KEY_BLOB_ID = "b";
-	private final static String KEY_THUMBNAIL_BLOB_ID = "t";
-	private final static String KEY_ENCRYPTION_KEY = "k";
-	private final static String KEY_MIME_TYPE = "m";
-	private final static String KEY_FILE_NAME = "n";
-	private final static String KEY_FILE_SIZE = "s";
-	private final static String KEY_TYPE = "i";
+	private static final String KEY_BLOB_ID = "b";
+	private static final String KEY_THUMBNAIL_BLOB_ID = "t";
+	private static final String KEY_ENCRYPTION_KEY = "k";
+	private static final String KEY_MIME_TYPE = "m";
+	private static final String KEY_FILE_NAME = "n";
+	private static final String KEY_FILE_SIZE = "s";
+	private static final String KEY_TYPE = "i";
 
 	public static final int TYPE_CODE = 0x17;
 
diff --git a/source/src/test/java/ch/threema/apitool/Common.java b/source/src/test/java/ch/threema/apitool/Common.java
index c3af9a0..2ff03cc 100644
--- a/source/src/test/java/ch/threema/apitool/Common.java
+++ b/source/src/test/java/ch/threema/apitool/Common.java
@@ -29,17 +29,17 @@
  */
 public abstract class Common {
 
-	public static final String myPrivateKey = "private:94af3260fa2a19adc8e82e82be598be15bc6ad6f47c8ee303cb185ef860e16d2";
-	public static final String myPrivateKeyExtract = "94af3260fa2a19adc8e82e82be598be15bc6ad6f47c8ee303cb185ef860e16d2";
+	public static final String MY_PRIVATE_KEY = "private:94af3260fa2a19adc8e82e82be598be15bc6ad6f47c8ee303cb185ef860e16d2";
+	public static final String MY_PRIVATE_KEY_EXTRACT = "94af3260fa2a19adc8e82e82be598be15bc6ad6f47c8ee303cb185ef860e16d2";
 
-	public static final String myPublicKey = "public:3851ad59c96146a05b32e41c0ccd0fd639dc8cd66bf6e1cbd3c8d67e4e8f5531";
-	public static final String myPublicKeyExtract = "3851ad59c96146a05b32e41c0ccd0fd639dc8cd66bf6e1cbd3c8d67e4e8f5531";
+	public static final String MY_PUBLIC_KEY = "public:3851ad59c96146a05b32e41c0ccd0fd639dc8cd66bf6e1cbd3c8d67e4e8f5531";
+	public static final String MY_PUBLIC_KEY_EXTRACT = "3851ad59c96146a05b32e41c0ccd0fd639dc8cd66bf6e1cbd3c8d67e4e8f5531";
 
-	public static final String otherPrivateKey = "private:8318e05220acd38e97ba41a9a6318688214219916075ca060f9339a6d1f7fc29";
-	public static final String otherPublicKey = "public:10ac7fd937eafb806f9a05bf9afa340a99387b0063cc9cb0d1ea5505d39cc076";
+	public static final String OTHER_PRIVATE_KEY = "private:8318e05220acd38e97ba41a9a6318688214219916075ca060f9339a6d1f7fc29";
+	public static final String OTHER_PUBLIC_KEY = "public:10ac7fd937eafb806f9a05bf9afa340a99387b0063cc9cb0d1ea5505d39cc076";
 
-	public static final String echochoPublicKey = "public:4a6a1b34dcef15d43cb74de2fd36091be99fbbaf126d099d47d83d919712c72b";
-	public static final String randomNonce = "516f4f1562dda0704a7bae8997cf0b354c6980181152ac32";
+	public static final String ECHOCHO_PUBLIC_KEY = "public:4a6a1b34dcef15d43cb74de2fd36091be99fbbaf126d099d47d83d919712c72b";
+	public static final String RANDOM_NONCE = "516f4f1562dda0704a7bae8997cf0b354c6980181152ac32";
 
 	public static boolean isEmpty(byte[] byteArray) {
 		if(byteArray == null) {
diff --git a/source/src/test/java/ch/threema/apitool/CryptToolTest.java b/source/src/test/java/ch/threema/apitool/CryptToolTest.java
index ddb563b..3dcb742 100644
--- a/source/src/test/java/ch/threema/apitool/CryptToolTest.java
+++ b/source/src/test/java/ch/threema/apitool/CryptToolTest.java
@@ -59,8 +59,8 @@ public void testDecrypt() throws Exception {
 		String nonce = "0a1ec5b67b4d61a1ef91f55e8ce0471fee96ea5d8596dfd0";
 		String box = "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";
 
-		Key privateKey = Key.decodeKey(Common.otherPrivateKey);
-		Key publicKey = Key.decodeKey(Common.myPublicKey);
+		Key privateKey = Key.decodeKey(Common.OTHER_PRIVATE_KEY);
+		Key publicKey = Key.decodeKey(Common.MY_PUBLIC_KEY);
 
 		ThreemaMessage message = CryptTool.decryptMessage(
 				DataUtils.hexStringToByteArray(box),
@@ -79,8 +79,8 @@ public void testEncrypt() throws Exception {
 		String text = "Dies ist eine Testnachricht. äöü";
 		String nonce = "0a1ec5b67b4d61a1ef91f55e8ce0471fee96ea5d8596dfd0";
 
-		Key privateKey = Key.decodeKey(Common.myPrivateKey);
-		Key publicKey = Key.decodeKey(Common.otherPublicKey);
+		Key privateKey = Key.decodeKey(Common.MY_PRIVATE_KEY);
+		Key publicKey = Key.decodeKey(Common.OTHER_PUBLIC_KEY);
 
 		EncryptResult res = CryptTool.encryptTextMessage(text, privateKey.key, publicKey.key);
 		Assert.assertNotNull(res);
@@ -92,8 +92,8 @@ public void testEncrypt() throws Exception {
 
 	@Test
 	public void testDerivePublicKey() throws Exception{
-		Key privateKey = Key.decodeKey(Common.myPrivateKey);
-		Key publicKey = Key.decodeKey(Common.myPublicKey);
+		Key privateKey = Key.decodeKey(Common.MY_PRIVATE_KEY);
+		Key publicKey = Key.decodeKey(Common.MY_PUBLIC_KEY);
 		byte[] derivedPublicKey = CryptTool.derivePublicKey(privateKey.key);
 		Assert.assertNotNull("derived public key", derivedPublicKey);
 		Assert.assertEquals(derivedPublicKey, publicKey.key);
diff --git a/source/src/test/java/ch/threema/apitool/KeyTest.java b/source/src/test/java/ch/threema/apitool/KeyTest.java
index 104188b..a2d3ec6 100644
--- a/source/src/test/java/ch/threema/apitool/KeyTest.java
+++ b/source/src/test/java/ch/threema/apitool/KeyTest.java
@@ -58,7 +58,7 @@ public void testDecodeKeyPublic() throws Exception {
 
 	@Test
 	public void testEncodePrivate() throws Exception {
-		byte[] keyAsByte = DataUtils.hexStringToByteArray(Common.myPrivateKeyExtract);
+		byte[] keyAsByte = DataUtils.hexStringToByteArray(Common.MY_PRIVATE_KEY_EXTRACT);
 
 		Key key = new Key(Key.KeyType.PRIVATE, keyAsByte);
 		Assert.assertNotNull("key instance", key);
@@ -66,6 +66,6 @@ public void testEncodePrivate() throws Exception {
 		Assert.assertEquals(Key.KeyType.PRIVATE, key.type);
 		Assert.assertEquals(key.key, keyAsByte);
 
-		Assert.assertEquals(key.encode(), Common.myPrivateKey);
+		Assert.assertEquals(key.encode(), Common.MY_PRIVATE_KEY);
 	}
 }
\ No newline at end of file