Java tutorial
/* * Copyright (C) 2013 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.android.tools.lint.checks; import com.android.annotations.NonNull; import com.android.annotations.Nullable; import com.android.tools.lint.detector.api.Category; import com.android.tools.lint.detector.api.Context; import com.android.tools.lint.detector.api.Detector; import com.android.tools.lint.detector.api.Implementation; import com.android.tools.lint.detector.api.Issue; import com.android.tools.lint.detector.api.JavaContext; import com.android.tools.lint.detector.api.Scope; import com.android.tools.lint.detector.api.Severity; import com.google.common.collect.Maps; import java.io.File; import java.util.Collections; import java.util.List; import java.util.Map; import lombok.ast.AstVisitor; import lombok.ast.Cast; import lombok.ast.Expression; import lombok.ast.MethodInvocation; import lombok.ast.StrictListAccessor; /** * Detector looking for casts on th result of context.getSystemService which are suspect */ public class ServiceCastDetector extends Detector implements Detector.JavaScanner { /** The main issue discovered by this detector */ public static final Issue ISSUE = Issue.create("ServiceCast", //$NON-NLS-1$ "Wrong system service casts", "When you call `Context#getSystemService()`, the result is typically cast to " + "a specific interface. This lint check ensures that the cast is compatible with " + "the expected type of the return value.", Category.CORRECTNESS, 6, Severity.FATAL, new Implementation(ServiceCastDetector.class, Scope.JAVA_FILE_SCOPE)); /** Constructs a new {@link ServiceCastDetector} check */ public ServiceCastDetector() { } @Override public boolean appliesTo(@NonNull Context context, @NonNull File file) { return true; } // ---- Implements JavaScanner ---- @Override public List<String> getApplicableMethodNames() { return Collections.singletonList("getSystemService"); //$NON-NLS-1$ } @Override public void visitMethod(@NonNull JavaContext context, @Nullable AstVisitor visitor, @NonNull MethodInvocation node) { if (node.getParent() instanceof Cast) { Cast cast = (Cast) node.getParent(); StrictListAccessor<Expression, MethodInvocation> args = node.astArguments(); if (args.size() == 1) { String name = stripPackage(args.first().toString()); String expectedClass = getExpectedType(name); if (expectedClass != null) { String castType = cast.astTypeReference().getTypeName(); if (castType.indexOf('.') == -1) { expectedClass = stripPackage(expectedClass); } if (!castType.equals(expectedClass)) { // It's okay to mix and match // android.content.ClipboardManager and android.text.ClipboardManager if (isClipboard(castType) && isClipboard(expectedClass)) { return; } String message = String.format("Suspicious cast to `%1$s` for a `%2$s`: expected `%3$s`", stripPackage(castType), name, stripPackage(expectedClass)); context.report(ISSUE, node, context.getLocation(cast), message); } } } } } private static boolean isClipboard(String cls) { return cls.equals("android.content.ClipboardManager") //$NON-NLS-1$ || cls.equals("android.text.ClipboardManager"); //$NON-NLS-1$ } private static String stripPackage(String fqcn) { int index = fqcn.lastIndexOf('.'); if (index != -1) { fqcn = fqcn.substring(index + 1); } return fqcn; } @Nullable private static String getExpectedType(@NonNull String value) { return getServiceMap().get(value); } @NonNull private static Map<String, String> getServiceMap() { if (sServiceMap == null) { final int EXPECTED_SIZE = 49; sServiceMap = Maps.newHashMapWithExpectedSize(EXPECTED_SIZE); sServiceMap.put("ACCESSIBILITY_SERVICE", "android.view.accessibility.AccessibilityManager"); sServiceMap.put("ACCOUNT_SERVICE", "android.accounts.AccountManager"); sServiceMap.put("ACTIVITY_SERVICE", "android.app.ActivityManager"); sServiceMap.put("ALARM_SERVICE", "android.app.AlarmManager"); sServiceMap.put("APPWIDGET_SERVICE", "android.appwidget.AppWidgetManager"); sServiceMap.put("APP_OPS_SERVICE", "android.app.AppOpsManager"); sServiceMap.put("AUDIO_SERVICE", "android.media.AudioManager"); sServiceMap.put("BATTERY_SERVICE", "android.os.BatteryManager"); sServiceMap.put("BLUETOOTH_SERVICE", "android.bluetooth.BluetoothManager"); sServiceMap.put("CAMERA_SERVICE", "android.hardware.camera2.CameraManager"); sServiceMap.put("CAPTIONING_SERVICE", "android.view.accessibility.CaptioningManager"); sServiceMap.put("CLIPBOARD_SERVICE", "android.text.ClipboardManager"); sServiceMap.put("CONNECTIVITY_SERVICE", "android.net.ConnectivityManager"); sServiceMap.put("CONSUMER_IR_SERVICE", "android.hardware.ConsumerIrManager"); sServiceMap.put("DEVICE_POLICY_SERVICE", "android.app.admin.DevicePolicyManager"); sServiceMap.put("DISPLAY_SERVICE", "android.hardware.display.DisplayManager"); sServiceMap.put("DOWNLOAD_SERVICE", "android.app.DownloadManager"); sServiceMap.put("DROPBOX_SERVICE", "android.os.DropBoxManager"); sServiceMap.put("INPUT_METHOD_SERVICE", "android.view.inputmethod.InputMethodManager"); sServiceMap.put("INPUT_SERVICE", "android.hardware.input.InputManager"); sServiceMap.put("JOB_SCHEDULER_SERVICE", "android.app.job.JobScheduler"); sServiceMap.put("KEYGUARD_SERVICE", "android.app.KeyguardManager"); sServiceMap.put("LAUNCHER_APPS_SERVICE", "android.content.pm.LauncherApps"); sServiceMap.put("LAYOUT_INFLATER_SERVICE", "android.view.LayoutInflater"); sServiceMap.put("LOCATION_SERVICE", "android.location.LocationManager"); sServiceMap.put("MEDIA_PROJECTION_SERVICE", "android.media.projection.MediaProjectionManager"); sServiceMap.put("MEDIA_ROUTER_SERVICE", "android.media.MediaRouter"); sServiceMap.put("MEDIA_SESSION_SERVICE", "android.media.session.MediaSessionManager"); sServiceMap.put("NFC_SERVICE", "android.nfc.NfcManager"); sServiceMap.put("NOTIFICATION_SERVICE", "android.app.NotificationManager"); sServiceMap.put("NSD_SERVICE", "android.net.nsd.NsdManager"); sServiceMap.put("POWER_SERVICE", "android.os.PowerManager"); sServiceMap.put("PRINT_SERVICE", "android.print.PrintManager"); sServiceMap.put("RESTRICTIONS_SERVICE", "android.content.RestrictionsManager"); sServiceMap.put("SEARCH_SERVICE", "android.app.SearchManager"); sServiceMap.put("SENSOR_SERVICE", "android.hardware.SensorManager"); sServiceMap.put("STORAGE_SERVICE", "android.os.storage.StorageManager"); sServiceMap.put("TELECOM_SERVICE", "android.telecom.TelecomManager"); sServiceMap.put("TELEPHONY_SERVICE", "android.telephony.TelephonyManager"); sServiceMap.put("TEXT_SERVICES_MANAGER_SERVICE", "android.view.textservice.TextServicesManager"); sServiceMap.put("TV_INPUT_SERVICE", "android.media.tv.TvInputManager"); sServiceMap.put("UI_MODE_SERVICE", "android.app.UiModeManager"); sServiceMap.put("USB_SERVICE", "android.hardware.usb.UsbManager"); sServiceMap.put("USER_SERVICE", "android.os.UserManager"); sServiceMap.put("VIBRATOR_SERVICE", "android.os.Vibrator"); sServiceMap.put("WALLPAPER_SERVICE", "com.android.server.WallpaperService"); sServiceMap.put("WIFI_P2P_SERVICE", "android.net.wifi.p2p.WifiP2pManager"); sServiceMap.put("WIFI_SERVICE", "android.net.wifi.WifiManager"); sServiceMap.put("WINDOW_SERVICE", "android.view.WindowManager"); assert sServiceMap.size() == EXPECTED_SIZE : sServiceMap.size(); } return sServiceMap; } private static Map<String, String> sServiceMap; }