Completely removed CommaSeparatedList class, replaced with two helper methods in Utils.

The two helper methods alleviate the need for copious null checks. They also provide
consistent behaviour when there are zero elements (i.e. they return null, rather than
an empty string or empty array, as was the case before).

app/src/main/java/org/fdroid/fdroid/AppFilter.java

@@ -27,7 +27,7 @@ public class AppFilter {
     public boolean filter(App app) {
         if (app.requirements != null && !Preferences.get().filterAppsRequiringRoot()) {
             for (String requirement : app.requirements) {
-                if (requirement.equals("root")) {
+                if ("root".equals(requirement)) {
                     return true;
                 }
             }

app/src/main/java/org/fdroid/fdroid/CompatibilityChecker.java

@@ -7,6 +7,7 @@ import android.content.pm.PackageManager;
 import android.os.Build;
 import android.preference.PreferenceManager;
 import android.support.annotation.Nullable;
+import android.text.TextUtils;
 
 import org.fdroid.fdroid.compat.SupportedArchitectures;
 import org.fdroid.fdroid.data.Apk;
@@ -114,7 +115,7 @@ public class CompatibilityChecker {
         if (!compatibleApi(apk.nativecode)) {
             Collections.addAll(incompatibleReasons, apk.nativecode);
             Utils.debugLog(TAG, apk.packageName + " vercode " + apk.versionCode
-                    + " only supports " + Utils.CommaSeparatedList.str(apk.nativecode)
+                    + " only supports " + TextUtils.join(", ", apk.nativecode)
                     + " while your architectures are " + cpuAbisDesc);
         }
 

app/src/main/java/org/fdroid/fdroid/RepoXMLHandler.java

@@ -142,13 +142,13 @@ public class RepoXMLHandler extends DefaultHandler {
                     curapk.added = Utils.parseDate(str, null);
                     break;
                 case "permissions":
-                    curapk.permissions = Utils.CommaSeparatedList.make(str);
+                    curapk.permissions = Utils.parseCommaSeparatedString(str);
                     break;
                 case "features":
-                    curapk.features = Utils.CommaSeparatedList.make(str);
+                    curapk.features = Utils.parseCommaSeparatedString(str);
                     break;
                 case "nativecode":
-                    curapk.nativecode = Utils.CommaSeparatedList.make(str);
+                    curapk.nativecode = Utils.parseCommaSeparatedString(str);
                     break;
             }
         } else if (curapp != null) {
@@ -218,13 +218,13 @@ public class RepoXMLHandler extends DefaultHandler {
                     curapp.upstreamVersionCode = Utils.parseInt(str, -1);
                     break;
                 case "categories":
-                    curapp.categories = Utils.CommaSeparatedList.make(str);
+                    curapp.categories = Utils.parseCommaSeparatedString(str);
                     break;
                 case "antifeatures":
-                    curapp.antiFeatures = Utils.CommaSeparatedList.make(str);
+                    curapp.antiFeatures = Utils.parseCommaSeparatedString(str);
                     break;
                 case "requirements":
-                    curapp.requirements = Utils.CommaSeparatedList.make(str);
+                    curapp.requirements = Utils.parseCommaSeparatedString(str);
                     break;
             }
         } else if ("description".equals(localName)) {

app/src/main/java/org/fdroid/fdroid/Utils.java

@@ -57,12 +57,8 @@ import java.security.cert.CertificateEncodingException;
 import java.text.DateFormat;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
-import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Date;
 import java.util.Formatter;
-import java.util.Iterator;
-import java.util.List;
 import java.util.Locale;
 
 public final class Utils {
@@ -403,36 +399,6 @@ public final class Utils {
         return new Locale(languageTag);
     }
 
-    public static final class CommaSeparatedList {
-        @Nullable
-        public static String[] make(List<String> list) {
-            if (list == null || list.isEmpty()) {
-                return null;
-            }
-            return list.toArray(new String[list.size()]);
-        }
-
-        @Nullable
-        public static String[] make(String[] list) {
-            if (list == null || list.length == 0) {
-                return null;
-            }
-            return list;
-        }
-
-        @Nullable
-        public static String[] make(@Nullable String list) {
-            if (TextUtils.isEmpty(list)) {
-                return null;
-            }
-            return list.split(",");
-        }
-
-        public static String str(@Nullable String[] values) {
-            return values == null ? null : TextUtils.join(",", values);
-        }
-    }
-
     public static DisplayImageOptions.Builder getImageLoadingOptions() {
         return new DisplayImageOptions.Builder()
                 .cacheInMemory(true)
@@ -510,6 +476,16 @@ public final class Utils {
         return result;
     }
 
+    @Nullable
+    public static String[] parseCommaSeparatedString(String values) {
+        return values == null || values.length() == 0 ? null : values.split(",");
+    }
+
+    @Nullable
+    public static String serializeCommaSeparatedString(@Nullable String[] values) {
+        return values == null || values.length == 0 ? null : TextUtils.join(",", values);
+    }
+
     private static Date parseDateFormat(DateFormat format, String str, Date fallback) {
         if (str == null || str.length() == 0) {
             return fallback;

app/src/main/java/org/fdroid/fdroid/data/Apk.java

@@ -83,7 +83,7 @@ public class Apk extends ValueObject implements Comparable<Apk> {
                     added = Utils.parseDate(cursor.getString(i), null);
                     break;
                 case ApkProvider.DataColumns.FEATURES:
-                    features = Utils.CommaSeparatedList.make(cursor.getString(i));
+                    features = Utils.parseCommaSeparatedString(cursor.getString(i));
                     break;
                 case ApkProvider.DataColumns.PACKAGE_NAME:
                     packageName = cursor.getString(i);
@@ -104,13 +104,13 @@ public class Apk extends ValueObject implements Comparable<Apk> {
                     apkName = cursor.getString(i);
                     break;
                 case ApkProvider.DataColumns.PERMISSIONS:
-                    permissions = Utils.CommaSeparatedList.make(cursor.getString(i));
+                    permissions = Utils.parseCommaSeparatedString(cursor.getString(i));
                     break;
                 case ApkProvider.DataColumns.NATIVE_CODE:
-                    nativecode = Utils.CommaSeparatedList.make(cursor.getString(i));
+                    nativecode = Utils.parseCommaSeparatedString(cursor.getString(i));
                     break;
                 case ApkProvider.DataColumns.INCOMPATIBLE_REASONS:
-                    incompatibleReasons = Utils.CommaSeparatedList.make(cursor.getString(i));
+                    incompatibleReasons = Utils.parseCommaSeparatedString(cursor.getString(i));
                     break;
                 case ApkProvider.DataColumns.REPO_ID:
                     repo = cursor.getInt(i);
@@ -205,10 +205,10 @@ public class Apk extends ValueObject implements Comparable<Apk> {
         values.put(ApkProvider.DataColumns.TARGET_SDK_VERSION, targetSdkVersion);
         values.put(ApkProvider.DataColumns.MAX_SDK_VERSION, maxSdkVersion);
         values.put(ApkProvider.DataColumns.ADDED_DATE, Utils.formatDate(added, ""));
-        values.put(ApkProvider.DataColumns.PERMISSIONS, Utils.CommaSeparatedList.str(permissions));
+        values.put(ApkProvider.DataColumns.PERMISSIONS, Utils.serializeCommaSeparatedString(permissions));
-        values.put(ApkProvider.DataColumns.FEATURES, Utils.CommaSeparatedList.str(features));
+        values.put(ApkProvider.DataColumns.FEATURES, Utils.serializeCommaSeparatedString(features));
-        values.put(ApkProvider.DataColumns.NATIVE_CODE, Utils.CommaSeparatedList.str(nativecode));
+        values.put(ApkProvider.DataColumns.NATIVE_CODE, Utils.serializeCommaSeparatedString(nativecode));
-        values.put(ApkProvider.DataColumns.INCOMPATIBLE_REASONS, Utils.CommaSeparatedList.str(incompatibleReasons));
+        values.put(ApkProvider.DataColumns.INCOMPATIBLE_REASONS, Utils.serializeCommaSeparatedString(incompatibleReasons));
         values.put(ApkProvider.DataColumns.IS_COMPATIBLE, compatible ? 1 : 0);
         return values;
     }

app/src/main/java/org/fdroid/fdroid/data/App.java

@@ -221,13 +221,13 @@ public class App extends ValueObject implements Comparable<App> {
                     lastUpdated = Utils.parseDate(cursor.getString(i), null);
                     break;
                 case AppProvider.DataColumns.CATEGORIES:
-                    categories = Utils.CommaSeparatedList.make(cursor.getString(i));
+                    categories = Utils.parseCommaSeparatedString(cursor.getString(i));
                     break;
                 case AppProvider.DataColumns.ANTI_FEATURES:
-                    antiFeatures = Utils.CommaSeparatedList.make(cursor.getString(i));
+                    antiFeatures = Utils.parseCommaSeparatedString(cursor.getString(i));
                     break;
                 case AppProvider.DataColumns.REQUIREMENTS:
-                    requirements = Utils.CommaSeparatedList.make(cursor.getString(i));
+                    requirements = Utils.parseCommaSeparatedString(cursor.getString(i));
                     break;
                 case AppProvider.DataColumns.IGNORE_ALLUPDATES:
                     ignoreAllUpdates = cursor.getInt(i) == 1;
@@ -334,7 +334,7 @@ public class App extends ValueObject implements Comparable<App> {
         apk.targetSdkVersion = minTargetMax[1];
         apk.maxSdkVersion = minTargetMax[2];
         apk.packageName = this.packageName;
-        apk.permissions = Utils.CommaSeparatedList.make(packageInfo.requestedPermissions);
+        apk.permissions = packageInfo.requestedPermissions;
         apk.apkName = apk.packageName + "_" + apk.versionCode + ".apk";
         apk.installedFile = apkFile;
 
@@ -348,15 +348,14 @@ public class App extends ValueObject implements Comparable<App> {
                 abis.add(matcher.group(1));
             }
         }
-        apk.nativecode = Utils.CommaSeparatedList.make(abis.toArray(new String[abis.size()]));
+        apk.nativecode = abis.toArray(new String[abis.size()]);
 
         final FeatureInfo[] features = packageInfo.reqFeatures;
         if (features != null && features.length > 0) {
-            final String[] featureNames = new String[features.length];
+            apk.features = new String[features.length];
             for (int i = 0; i < features.length; i++) {
-                featureNames[i] = features[i].name;
+                apk.features[i] = features[i].name;
             }
-            apk.features = Utils.CommaSeparatedList.make(featureNames);
         }
 
         final JarEntry aSignedEntry = (JarEntry) apkJar.getEntry("AndroidManifest.xml");
@@ -462,9 +461,9 @@ public class App extends ValueObject implements Comparable<App> {
         values.put(AppProvider.DataColumns.SUGGESTED_VERSION_CODE, suggestedVersionCode);
         values.put(AppProvider.DataColumns.UPSTREAM_VERSION_NAME, upstreamVersionName);
         values.put(AppProvider.DataColumns.UPSTREAM_VERSION_CODE, upstreamVersionCode);
-        values.put(AppProvider.DataColumns.CATEGORIES, Utils.CommaSeparatedList.str(categories));
+        values.put(AppProvider.DataColumns.CATEGORIES, Utils.serializeCommaSeparatedString(categories));
-        values.put(AppProvider.DataColumns.ANTI_FEATURES, Utils.CommaSeparatedList.str(antiFeatures));
+        values.put(AppProvider.DataColumns.ANTI_FEATURES, Utils.serializeCommaSeparatedString(antiFeatures));
-        values.put(AppProvider.DataColumns.REQUIREMENTS, Utils.CommaSeparatedList.str(requirements));
+        values.put(AppProvider.DataColumns.REQUIREMENTS, Utils.serializeCommaSeparatedString(requirements));
         values.put(AppProvider.DataColumns.IS_COMPATIBLE, compatible ? 1 : 0);
         values.put(AppProvider.DataColumns.IGNORE_ALLUPDATES, ignoreAllUpdates ? 1 : 0);
         values.put(AppProvider.DataColumns.IGNORE_THISUPDATE, ignoreThisUpdate);

app/src/main/java/org/fdroid/fdroid/data/AppProvider.java

@@ -98,7 +98,7 @@ public class AppProvider extends FDroidProvider {
                     cursor.moveToFirst();
                     while (!cursor.isAfterLast()) {
                         final String categoriesString = cursor.getString(0);
-                        String[] categoriesList = Utils.CommaSeparatedList.make(categoriesString);
+                        String[] categoriesList = Utils.parseCommaSeparatedString(categoriesString);
                         if (categoriesList != null) {
                             Collections.addAll(categorySet, categoriesList);
                         }

app/src/main/java/org/fdroid/fdroid/data/RepoPersister.java

@@ -284,7 +284,7 @@ public class RepoPersister {
             final List<String> reasons = checker.getIncompatibleReasons(apk);
             if (reasons.size() > 0) {
                 apk.compatible = false;
-                apk.incompatibleReasons = Utils.CommaSeparatedList.make(reasons);
+                apk.incompatibleReasons = reasons.toArray(new String[reasons.size()]);
             } else {
                 apk.compatible = true;
                 apk.incompatibleReasons = null;

app/src/main/java/org/fdroid/fdroid/localrepo/LocalRepoManager.java

@@ -454,7 +454,7 @@ public final class LocalRepoManager {
         private void tagFeatures(App app) throws IOException {
             serializer.startTag("", "features");
             if (app.installedApk.features != null) {
-                serializer.text(Utils.CommaSeparatedList.str(app.installedApk.features));
+                serializer.text(TextUtils.join(",", app.installedApk.features));
             }
             serializer.endTag("", "features");
         }
@@ -462,7 +462,7 @@ public final class LocalRepoManager {
         private void tagNativecode(App app) throws IOException {
             if (app.installedApk.nativecode != null) {
                 serializer.startTag("", "nativecode");
-                serializer.text(Utils.CommaSeparatedList.str(app.installedApk.nativecode));
+                serializer.text(TextUtils.join(",", app.installedApk.nativecode));
                 serializer.endTag("", "nativecode");
             }
         }

app/src/test/java/org/fdroid/fdroid/data/ApkProviderTest.java

@@ -7,7 +7,6 @@ import android.net.Uri;
 
 import org.fdroid.fdroid.Assert;
 import org.fdroid.fdroid.BuildConfig;
-import org.fdroid.fdroid.Utils;
 import org.fdroid.fdroid.mock.MockApk;
 import org.fdroid.fdroid.mock.MockApp;
 import org.fdroid.fdroid.mock.MockRepo;
@@ -410,7 +409,7 @@ public class ApkProviderTest extends FDroidProviderTest {
         assertNull(apk.added);
         assertNull(apk.hashType);
 
-        apk.features = Utils.CommaSeparatedList.make("one,two,three");
+        apk.features = new String[] {"one", "two", "three" };
         long dateTimestamp = System.currentTimeMillis();
         apk.added = new Date(dateTimestamp);
         apk.hashType = "i'm a hash type";