diff --git a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/helper/ActionBarHelper.java b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/helper/ActionBarHelper.java
index 2276e0f8a..24e8ff4c7 100644
--- a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/helper/ActionBarHelper.java
+++ b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/helper/ActionBarHelper.java
@@ -22,7 +22,6 @@ import org.sufficientlysecure.keychain.R;
 import org.sufficientlysecure.keychain.util.Log;
 
 import android.app.Activity;
-import android.graphics.drawable.Drawable;
 import android.support.v7.app.ActionBar;
 import android.support.v7.app.ActionBarActivity;
 import android.view.LayoutInflater;
diff --git a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/helper/Preferences.java b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/helper/Preferences.java
index 493f25707..f18a290b3 100644
--- a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/helper/Preferences.java
+++ b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/helper/Preferences.java
@@ -144,8 +144,8 @@ public class Preferences {
                 Constants.defaults.KEY_SERVERS);
         Vector<String> servers = new Vector<String>();
         String chunks[] = rawData.split(",");
-        for (int i = 0; i < chunks.length; ++i) {
-            String tmp = chunks[i].trim();
+        for (String c : chunks) {
+            String tmp = c.trim();
             if (tmp.length() > 0) {
                 servers.add(tmp);
             }
@@ -156,8 +156,8 @@ public class Preferences {
     public void setKeyServers(String[] value) {
         SharedPreferences.Editor editor = mSharedPreferences.edit();
         String rawData = "";
-        for (int i = 0; i < value.length; ++i) {
-            String tmp = value[i].trim();
+        for (String v : value) {
+            String tmp = v.trim();
             if (tmp.length() == 0) {
                 continue;
             }
diff --git a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpHelper.java b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpHelper.java
index 7ac904d89..1db4f98b1 100644
--- a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpHelper.java
+++ b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpHelper.java
@@ -193,11 +193,10 @@ public class PgpHelper {
      * @param context
      * @param progress
      * @param file
-     * @throws FileNotFoundException
      * @throws IOException
      */
     public static void deleteFileSecurely(Context context, ProgressDialogUpdater progress, File file)
-            throws FileNotFoundException, IOException {
+            throws IOException {
         long length = file.length();
         SecureRandom random = new SecureRandom();
         RandomAccessFile raf = new RandomAccessFile(file, "rws");
diff --git a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpImportExport.java b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpImportExport.java
index 0a17a2be4..138e54f71 100644
--- a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpImportExport.java
+++ b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpImportExport.java
@@ -79,8 +79,9 @@ public class PgpImportExport {
 
     public boolean uploadKeyRingToServer(HkpKeyServer server, PGPPublicKeyRing keyring) {
         ByteArrayOutputStream bos = new ByteArrayOutputStream();
-        ArmoredOutputStream aos = new ArmoredOutputStream(bos);
+        ArmoredOutputStream aos = null;
         try {
+            aos = new ArmoredOutputStream(bos);
             aos.write(keyring.getEncoded());
             aos.close();
 
@@ -95,7 +96,8 @@ public class PgpImportExport {
             return false;
         } finally {
             try {
-                bos.close();
+                if (aos != null) aos.close();
+                if (bos != null) bos.close();
             } catch (IOException e) {
             }
         }
@@ -156,7 +158,7 @@ public class PgpImportExport {
     }
 
     public Bundle exportKeyRings(ArrayList<Long> keyRingRowIds, int keyType,
-                                 OutputStream outStream) throws PgpGeneralException, FileNotFoundException,
+                                 OutputStream outStream) throws PgpGeneralException,
             PGPException, IOException {
         Bundle returnData = new Bundle();
 
diff --git a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpKeyOperation.java b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpKeyOperation.java
index e1ca88fb0..5ebb53f20 100644
--- a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpKeyOperation.java
+++ b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpKeyOperation.java
@@ -190,7 +190,7 @@ public class PgpKeyOperation {
     }
 
     public void changeSecretKeyPassphrase(PGPSecretKeyRing keyRing, String oldPassPhrase,
-            String newPassPhrase) throws IOException, PGPException, PGPException,
+            String newPassPhrase) throws IOException, PGPException,
             NoSuchProviderException {
 
         updateProgress(R.string.progress_building_key, 0, 100);
diff --git a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/service/PassphraseCacheService.java b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/service/PassphraseCacheService.java
index abd2320e3..ce34d451d 100644
--- a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/service/PassphraseCacheService.java
+++ b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/service/PassphraseCacheService.java
@@ -21,6 +21,7 @@ import java.util.Date;
 import java.util.HashMap;
 import java.util.Iterator;
 
+import android.util.LongSparseArray;
 import org.spongycastle.openpgp.PGPException;
 import org.spongycastle.openpgp.PGPPrivateKey;
 import org.spongycastle.openpgp.PGPSecretKey;
@@ -77,7 +78,7 @@ public class PassphraseCacheService extends Service {
 
     private BroadcastReceiver mIntentReceiver;
 
-    private HashMap<Long, String> mPassphraseCache = new HashMap<Long, String>();
+    private LongSparseArray<String> mPassphraseCache = new LongSparseArray<String>();
 
     Context mContext;
 
@@ -347,7 +348,7 @@ public class PassphraseCacheService extends Service {
         Log.d(TAG, "Timeout of keyId " + keyId + ", removed from memory!");
 
         // stop whole service if no cached passphrases remaining
-        if (mPassphraseCache.isEmpty()) {
+        if (mPassphraseCache.size() == 0) {
             Log.d(TAG, "No passphrases remaining in memory, stopping service!");
             stopSelf();
         }
diff --git a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/DecryptActivity.java b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/DecryptActivity.java
index 76acf15b0..38d763ce4 100644
--- a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/DecryptActivity.java
+++ b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/DecryptActivity.java
@@ -530,6 +530,10 @@ public class DecryptActivity extends DrawerActivity {
                 Log.e(Constants.TAG, "File not found!", e);
                 AppMsg.makeText(this, getString(R.string.error_file_not_found, e.getMessage()),
                         AppMsg.STYLE_ALERT).show();
+            } finally {
+                try {
+                    if (inStream != null) inStream.close();
+                } catch (Exception e){ }
             }
         } else {
             inStream = new ByteArrayInputStream(mMessage.getText().toString().getBytes());
diff --git a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/PreferencesKeyServerActivity.java b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/PreferencesKeyServerActivity.java
index 492e9f200..50fec1ffc 100644
--- a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/PreferencesKeyServerActivity.java
+++ b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/PreferencesKeyServerActivity.java
@@ -81,11 +81,11 @@ public class PreferencesKeyServerActivity extends ActionBarActivity implements O
         Intent intent = getIntent();
         String servers[] = intent.getStringArrayExtra(EXTRA_KEY_SERVERS);
         if (servers != null) {
-            for (int i = 0; i < servers.length; ++i) {
+            for (String serv : servers) {
                 KeyServerEditor view = (KeyServerEditor) mInflater.inflate(
                         R.layout.key_server_editor, mEditors, false);
                 view.setEditorListener(this);
-                view.setValue(servers[i]);
+                view.setValue(serv);
                 mEditors.addView(view);
             }
         }
diff --git a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/SelectPublicKeyFragment.java b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/SelectPublicKeyFragment.java
index c1c9aa705..d320af451 100644
--- a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/SelectPublicKeyFragment.java
+++ b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/SelectPublicKeyFragment.java
@@ -199,8 +199,8 @@ public class SelectPublicKeyFragment extends ListFragmentWorkaround implements T
         if (masterKeyIds != null) {
             for (int i = 0; i < getListView().getCount(); ++i) {
                 long keyId = mAdapter.getMasterKeyId(i);
-                for (int j = 0; j < masterKeyIds.length; ++j) {
-                    if (keyId == masterKeyIds[j]) {
+                for (long masterKeyId : masterKeyIds) {
+                    if (keyId == masterKeyId) {
                         getListView().setItemChecked(i, true);
                         break;
                     }
diff --git a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/adapter/KeyListPublicAdapter.java b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/adapter/KeyListPublicAdapter.java
index b8f60633e..d7bb62d01 100644
--- a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/adapter/KeyListPublicAdapter.java
+++ b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/adapter/KeyListPublicAdapter.java
@@ -18,8 +18,6 @@
 package org.sufficientlysecure.keychain.ui.adapter;
 
 import java.util.HashMap;
-import java.util.Set;
-
 
 import org.sufficientlysecure.keychain.Constants;
 import org.sufficientlysecure.keychain.R;
diff --git a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/adapter/KeyListSecretAdapter.java b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/adapter/KeyListSecretAdapter.java
index ca3a26066..0bffcaa19 100644
--- a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/adapter/KeyListSecretAdapter.java
+++ b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/adapter/KeyListSecretAdapter.java
@@ -18,7 +18,6 @@
 package org.sufficientlysecure.keychain.ui.adapter;
 
 import java.util.HashMap;
-import java.util.Set;
 
 import org.sufficientlysecure.keychain.R;
 import org.sufficientlysecure.keychain.pgp.PgpKeyHelper;
diff --git a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/dialog/CreateKeyDialogFragment.java b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/dialog/CreateKeyDialogFragment.java
index 98b677511..a47601c9b 100644
--- a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/dialog/CreateKeyDialogFragment.java
+++ b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/ui/dialog/CreateKeyDialogFragment.java
@@ -32,6 +32,7 @@ import org.sufficientlysecure.keychain.Id;
 import org.sufficientlysecure.keychain.R;
 import org.sufficientlysecure.keychain.util.Choice;
 
+import java.util.ArrayList;
 import java.util.Vector;
 
 public class CreateKeyDialogFragment extends DialogFragment {
@@ -78,7 +79,7 @@ public class CreateKeyDialogFragment extends DialogFragment {
         boolean wouldBeMasterKey = (childCount == 0);
 
         final Spinner algorithm = (Spinner) view.findViewById(R.id.create_key_algorithm);
-        Vector<Choice> choices = new Vector<Choice>();
+        ArrayList<Choice> choices = new ArrayList<Choice>();
         choices.add(new Choice(Id.choice.algorithm.dsa, getResources().getString(
                 R.string.dsa)));
         if (!wouldBeMasterKey) {
diff --git a/OpenPGP-Keychain/src/main/res/layout/api_app_error_message.xml b/OpenPGP-Keychain/src/main/res/layout/api_app_error_message.xml
index 5927dbf43..48aa89d4f 100644
--- a/OpenPGP-Keychain/src/main/res/layout/api_app_error_message.xml
+++ b/OpenPGP-Keychain/src/main/res/layout/api_app_error_message.xml
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout 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:orientation="vertical" >
diff --git a/OpenPGP-Keychain/src/main/res/layout/api_app_select_pub_keys_activity.xml b/OpenPGP-Keychain/src/main/res/layout/api_app_select_pub_keys_activity.xml
index 877b4e74e..a10592607 100644
--- a/OpenPGP-Keychain/src/main/res/layout/api_app_select_pub_keys_activity.xml
+++ b/OpenPGP-Keychain/src/main/res/layout/api_app_select_pub_keys_activity.xml
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout 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:orientation="vertical" >
diff --git a/OpenPGP-Keychain/src/main/res/layout/key_server_export.xml b/OpenPGP-Keychain/src/main/res/layout/key_server_export.xml
index c162a6e28..6031bf7c7 100644
--- a/OpenPGP-Keychain/src/main/res/layout/key_server_export.xml
+++ b/OpenPGP-Keychain/src/main/res/layout/key_server_export.xml
@@ -1,7 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:bootstrapbutton="http://schemas.android.com/apk/res-auto"
-    xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent" >