More static imports.

briar-android/src/main/java/org/briarproject/briar/android/ScreenFilterMonitorImpl.java

@@ -25,7 +25,6 @@ import java.security.cert.CertificateFactory;
 import java.security.cert.X509Certificate;
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -46,6 +45,9 @@ import static android.content.pm.PackageInfo.REQUESTED_PERMISSION_GRANTED;
 import static android.content.pm.PackageManager.GET_PERMISSIONS;
 import static android.content.pm.PackageManager.GET_SIGNATURES;
 import static android.os.Build.VERSION.SDK_INT;
+import static java.util.Collections.emptySet;
+import static java.util.Collections.sort;
+import static java.util.Collections.unmodifiableList;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logException;
@@ -105,8 +107,7 @@ class ScreenFilterMonitorImpl implements ScreenFilterMonitor, Service {
 	@UiThread
 	public Collection<AppDetails> getApps() {
 		if (cachedApps != null) return cachedApps;
-		Set<String> allowed = prefs.getStringSet(PREF_KEY_ALLOWED,
-				Collections.emptySet());
+		Set<String> allowed = prefs.getStringSet(PREF_KEY_ALLOWED, emptySet());
 		List<AppDetails> apps = new ArrayList<>();
 		List<PackageInfo> packageInfos =
 				pm.getInstalledPackages(GET_PERMISSIONS);
@@ -117,8 +118,8 @@ class ScreenFilterMonitorImpl implements ScreenFilterMonitor, Service {
 				apps.add(new AppDetails(name, packageInfo.packageName));
 			}
 		}
-		Collections.sort(apps, (a, b) -> a.name.compareTo(b.name));
-		apps = Collections.unmodifiableList(apps);
+		sort(apps, (a, b) -> a.name.compareTo(b.name));
+		apps = unmodifiableList(apps);
 		cachedApps = apps;
 		return apps;
 	}
@@ -127,8 +128,7 @@ class ScreenFilterMonitorImpl implements ScreenFilterMonitor, Service {
 	@UiThread
 	public void allowApps(Collection<String> packageNames) {
 		cachedApps = null;
-		Set<String> allowed = prefs.getStringSet(PREF_KEY_ALLOWED,
-				Collections.emptySet());
+		Set<String> allowed = prefs.getStringSet(PREF_KEY_ALLOWED, emptySet());
 		Set<String> merged = new HashSet<>(allowed);
 		merged.addAll(packageNames);
 		prefs.edit().putStringSet(PREF_KEY_ALLOWED, merged).apply();

briar-android/src/main/java/org/briarproject/briar/android/blog/BlogCommentItem.java

@@ -4,10 +4,11 @@ import org.briarproject.briar.api.blog.BlogCommentHeader;
 import org.briarproject.briar.api.blog.BlogPostHeader;
 
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
 
+import static java.util.Collections.sort;
+
 // This class is not thread-safe
 class BlogCommentItem extends BlogPostItem {
 
@@ -20,7 +21,7 @@ class BlogCommentItem extends BlogPostItem {
 	BlogCommentItem(BlogCommentHeader header) {
 		super(header, null);
 		postHeader = collectComments(header);
-		Collections.sort(comments, COMPARATOR);
+		sort(comments, COMPARATOR);
 	}
 
 	private BlogPostHeader collectComments(BlogPostHeader header) {

briar-android/src/main/java/org/briarproject/briar/android/reporting/BriarReportPrimer.java

@@ -7,7 +7,6 @@ import android.net.ConnectivityManager;
 import android.net.NetworkInfo;
 import android.net.wifi.WifiInfo;
 import android.net.wifi.WifiManager;
-import android.os.Build;
 import android.os.Environment;
 import android.os.Handler;
 import android.os.Looper;
@@ -23,7 +22,6 @@ import org.briarproject.briar.android.logging.BriefLogFormatter;
 import java.io.File;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
-import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.concurrent.Callable;
@@ -41,6 +39,8 @@ import static android.content.Context.WIFI_SERVICE;
 import static android.net.ConnectivityManager.TYPE_MOBILE;
 import static android.net.ConnectivityManager.TYPE_WIFI;
 import static android.net.wifi.WifiManager.WIFI_STATE_ENABLED;
+import static android.os.Build.VERSION.SDK_INT;
+import static java.util.Collections.unmodifiableMap;
 import static org.briarproject.bramble.util.PrivacyUtils.scrubInetAddress;
 import static org.briarproject.bramble.util.PrivacyUtils.scrubMacAddress;
 import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
@@ -90,7 +90,7 @@ public class BriarReportPrimer implements ReportPrimer {
 			ActivityManager.MemoryInfo mem = new ActivityManager.MemoryInfo();
 			am.getMemoryInfo(mem);
 			String systemMemory;
-			if (Build.VERSION.SDK_INT >= 16) {
+			if (SDK_INT >= 16) {
 				systemMemory = (mem.totalMem / 1024 / 1024) + " MiB total, "
 						+ (mem.availMem / 1024 / 1204) + " MiB free, "
 						+ (mem.threshold / 1024 / 1024) + " MiB threshold";
@@ -213,7 +213,7 @@ public class BriarReportPrimer implements ReportPrimer {
 					bt.getScanMode() == SCAN_MODE_CONNECTABLE_DISCOVERABLE;
 			// Is Bluetooth LE scanning and advertising supported?
 			boolean btLeApi = false, btLeScan = false, btLeAdvertise = false;
-			if (bt != null && Build.VERSION.SDK_INT >= 21) {
+			if (bt != null && SDK_INT >= 21) {
 				btLeApi = true;
 				btLeScan = bt.getBluetoothLeScanner() != null;
 				btLeAdvertise = bt.getBluetoothLeAdvertiser() != null;
@@ -255,7 +255,7 @@ public class BriarReportPrimer implements ReportPrimer {
 			// Git commit ID
 			customData.put("Commit ID", BuildConfig.GitHash);
 
-			return Collections.unmodifiableMap(customData);
+			return unmodifiableMap(customData);
 		}
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/settings/SettingsFragment.java

@@ -42,7 +42,6 @@ import org.briarproject.briar.android.Localizer;
 import org.briarproject.briar.android.navdrawer.NavDrawerActivity;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
 import java.util.Locale;
 import java.util.logging.Logger;
@@ -67,6 +66,7 @@ import static android.provider.Settings.EXTRA_CHANNEL_ID;
 import static android.provider.Settings.System.DEFAULT_NOTIFICATION_URI;
 import static android.support.v4.view.ViewCompat.LAYOUT_DIRECTION_LTR;
 import static android.widget.Toast.LENGTH_SHORT;
+import static java.util.Arrays.asList;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
@@ -222,7 +222,7 @@ public class SettingsFragment extends PreferenceFragmentCompat
 		if (SDK_INT < 27) {
 			// remove System Default Theme option
 			List<CharSequence> entries =
-					new ArrayList<>(Arrays.asList(theme.getEntries()));
+					new ArrayList<>(asList(theme.getEntries()));
 			entries.remove(getString(R.string.pref_theme_system));
 			theme.setEntries(entries.toArray(new CharSequence[0]));
 		}

briar-android/src/main/java/org/briarproject/briar/android/splash/SplashScreenActivity.java

@@ -1,7 +1,6 @@
 package org.briarproject.briar.android.splash;
 
 import android.content.Intent;
-import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
 import android.support.v7.preference.PreferenceManager;
@@ -21,6 +20,7 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
+import static android.os.Build.VERSION.SDK_INT;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.briar.android.TestingConstants.EXPIRY_DATE;
 
@@ -40,7 +40,7 @@ public class SplashScreenActivity extends BaseActivity {
 	public void onCreate(Bundle state) {
 		super.onCreate(state);
 
-		if (Build.VERSION.SDK_INT >= 21) {
+		if (SDK_INT >= 21) {
 			getWindow().setExitTransition(new Fade());
 		}
 

briar-android/src/main/java/org/briarproject/briar/android/threaded/ThreadListControllerImpl.java

@@ -28,12 +28,12 @@ import org.briarproject.briar.api.client.PostHeader;
 import org.briarproject.briar.api.client.ThreadedMessage;
 
 import java.util.Collection;
-import java.util.Collections;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
+import static java.util.Collections.singletonList;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
@@ -186,7 +186,7 @@ public abstract class ThreadListControllerImpl<G extends NamedGroup, I extends T
 
 	@Override
 	public void markItemRead(I item) {
-		markItemsRead(Collections.singletonList(item));
+		markItemsRead(singletonList(item));
 	}
 
 	@Override

briar-android/src/main/java/org/briarproject/briar/android/view/KeyboardAwareLinearLayout.java

@@ -8,7 +8,6 @@ import android.annotation.TargetApi;
 import android.content.Context;
 import android.content.SharedPreferences;
 import android.graphics.Rect;
-import android.os.Build;
 import android.preference.PreferenceManager;
 import android.support.annotation.UiThread;
 import android.util.AttributeSet;
@@ -26,6 +25,7 @@ import java.util.logging.Logger;
 import javax.annotation.Nullable;
 
 import static android.content.Context.WINDOW_SERVICE;
+import static android.os.Build.VERSION.SDK_INT;
 import static android.view.Surface.ROTATION_270;
 import static android.view.Surface.ROTATION_90;
 import static java.util.Objects.requireNonNull;
@@ -106,7 +106,7 @@ public class KeyboardAwareLinearLayout extends LinearLayout {
 			return;
 		}
 
-		if (viewInset == 0 && Build.VERSION.SDK_INT >= 21)
+		if (viewInset == 0 && SDK_INT >= 21)
 			viewInset = getViewInset();
 		int availableHeight =
 				getRootView().getHeight() - statusBarHeight - viewInset;

briar-android/src/test/java/org/briarproject/briar/android/forum/ForumActivityTest.java

@@ -21,8 +21,7 @@ import org.robolectric.Robolectric;
 import org.robolectric.RobolectricTestRunner;
 import org.robolectric.annotation.Config;
 
-import java.util.Arrays;
-
+import static java.util.Arrays.asList;
 import static junit.framework.Assert.assertEquals;
 import static junit.framework.Assert.assertTrue;
 import static org.briarproject.bramble.api.identity.AuthorInfo.Status.UNKNOWN;
@@ -91,7 +90,7 @@ public class ForumActivityTest {
 			forumItems[i].setLevel(LEVELS[i]);
 		}
 		ThreadItemList<ForumItem> list = new ThreadItemListImpl<>();
-		list.addAll(Arrays.asList(forumItems));
+		list.addAll(asList(forumItems));
 		return list;
 	}