关于 android 的JNI的java 调用 C和 C 调用JAVA（1）
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以前研究过 android的JNI调用！！后面忙于其他事情就忘记的差不多。最近又把它拿出来算作是复习吧。
0. Android中的JNI
Android的APP开发一般是用Java，用到的系统服务和操作系统相关的东西是用c写的。Java到c的访问，通过JNI(Java Native Interface)，一般情况下的考虑是Java -> c，也有c -> Java的情形，这在Android中经常使用。
1. Java域调用c域的函数
通常JNI的使用：
1) Java中某个类的方法声明前加上native修饰；
2) 在c中实现该方法，并把实现该方法的c文件编译进动态库；
3) 在java中使用该方法前，用System.loadLibrary()装载。
4) 在步骤2中的c文件中定义JNI_OnLoad，并在其中通过JNIEnv:: RegisterNatives()把Java里声明的Java native方法与c中定义的实现函数关联起来。
其中的实现细节不是本文描述的重点，如有疑问可参阅其它文章。
例如：MediaScanner.javapublic class MediaScanner{ static { System.loadLibrary("media_jni"); native_init(); }private int mNativeContext; private Context mContext; private IContentProvider mMediaProvider; private Uri mAudioUri;........ private native void processDirectory(String path, MediaScannerClient client); private native void processFile(String path, String mimeType, MediaScannerClient client); public native void setLocale(String locale); public native byte[] extractAlbumArt(FileDescriptor fd); private static native final void native_init(); private native final void native_setup(); private native final void native_finalize();}上面native都表示函数具体实现是在c或者c++中实现。
MediaScanner 在启动开始启动后立马加载动态库media_jni后初始或
native_init()实际调用的是frameworks\base\media\jni\android_media_MediaScanner.cpp中的static void
android_media_MediaScanner_native_init(JNIEnv *env)
函数具体内容是
static voidandroid_media_MediaScanner_native_init(JNIEnv *env){ ALOGV("native_init"); jclass clazz = env->FindClass(kClassMediaScanner); if (clazz == NULL) { return; } fields.context = env->GetFieldID(clazz, "mNativeContext", "I"); if (fields.context == NULL) { return; }}其中
(kClassMediaScanner定义为
static const char* const kClassMediaScanner = "android/media/MediaScanner";
首先通过
env->FindClass获取java对象
MediaScanner函数env->GetFieldID(clazz, "mNativeContext", "I") 中clazz= MediaScanner，mNativeContext 是MediaScanner.java 中的 private int mNativeContext;
I代表mNativeContext这个成员变量的属性。
struct fields_t {
jfieldID context;
};
static fields_t fields;mNativeContext
fields只有一个成员变量jfieldID ，jfieldID和jmethodid代表java的类的成员变量和成员函数。说白了就是操作 fields.context就是操作MediaScanner的mNativeContext
在
static voidandroid_media_MediaScanner_native_setup(JNIEnv *env, jobject thiz){ ALOGV("native_setup"); MediaScanner *mp = new StagefrightMediaScanner; if (mp == NULL) { jniThrowException(env, kRunTimeException, "Out of memory"); return; } env->SetIntField(thiz, fields.context, (int)mp);}中 通过MediaScanner *mp = new StagefrightMediaScanner; 生成了一个本地 MediaScanner对象。然后设置这个 mp对象的属性值 env->SetIntField(thiz, fields.context,
(int)mp);这时候mNativeContext的本地对象就是mp。
源码
/***** Copyright 2007, 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.*///#define LOG_NDEBUG 0#define LOG_TAG "MediaScannerJNI"#include <utils/Log.h>#include <utils/threads.h>#include <utils/Unicode.h>#include <media/mediascanner.h>#include <media/stagefright/StagefrightMediaScanner.h>#include "jni.h"#include "JNIHelp.h"#include "android_runtime/AndroidRuntime.h"using namespace android;static const char* const kClassMediaScannerClient = "android/media/MediaScannerClient";static const char* const kClassMediaScanner = "android/media/MediaScanner";static const char* const kRunTimeException = "java/lang/RuntimeException";static const char* const kIllegalArgumentException = "java/lang/IllegalArgumentException";struct fields_t { jfieldID context;};static fields_t fields;static status_t checkAndClearExceptionFromCallback(JNIEnv* env, const char* methodName) { if (env->ExceptionCheck()) { ALOGE("An exception was thrown by callback '%s'.", methodName); LOGE_EX(env); env->ExceptionClear(); return UNKNOWN_ERROR; } return OK;}class MyMediaScannerClient : public MediaScannerClient{public: MyMediaScannerClient(JNIEnv *env, jobject client, jobject scanner) : mEnv(env), mClient(env->NewGlobalRef(client)), mScanner(env->NewGlobalRef(scanner)), mScanFileMethodID(0), mHandleStringTagMethodID(0), mSetMimeTypeMethodID(0), mNeedStopFileID(0) { ALOGV("MyMediaScannerClient constructor"); jclass mediaScannerClientInterface = env->FindClass(kClassMediaScannerClient); jclass mediaScannerClass = env->FindClass(kClassMediaScanner); if ( (mediaScannerClientInterface == NULL) || (mediaScannerClass == NULL) ) { ALOGE("Class %s or %snot found", kClassMediaScannerClient, kClassMediaScanner); } else { mScanFileMethodID = env->GetMethodID( mediaScannerClientInterface, "scanFile", "(Ljava/lang/String;JJZZ)V"); mHandleStringTagMethodID = env->GetMethodID( mediaScannerClientInterface, "handleStringTag", "(Ljava/lang/String;Ljava/lang/String;)V"); mSetMimeTypeMethodID = env->GetMethodID( mediaScannerClientInterface, "setMimeType", "(Ljava/lang/String;)V"); mNeedStopFileID = env->GetFieldID(mediaScannerClass,"mStopScan","Z"); } } virtual ~MyMediaScannerClient() { ALOGV("MyMediaScannerClient destructor"); mEnv->DeleteGlobalRef(mClient); mEnv->DeleteGlobalRef(mScanner); } virtual status_t scanFile(const char* path, long long lastModified, long long fileSize, bool isDirectory, bool noMedia) { ALOGV("scanFile: path(%s), time(%lld), size(%lld) and isDir(%d)", path, lastModified, fileSize, isDirectory); jstring pathStr; if ((pathStr = mEnv->NewStringUTF(path)) == NULL) { mEnv->ExceptionClear(); return NO_MEMORY; } mEnv->CallVoidMethod(mClient, mScanFileMethodID, pathStr, lastModified, fileSize, isDirectory, noMedia); mEnv->DeleteLocalRef(pathStr); return checkAndClearExceptionFromCallback(mEnv, "scanFile"); } virtual status_t handleStringTag(const char* name, const char* value) { ALOGV("handleStringTag: name(%s) and value(%s)", name, value); jstring nameStr, valueStr; if ((nameStr = mEnv->NewStringUTF(name)) == NULL) { mEnv->ExceptionClear(); return NO_MEMORY; } // Check if the value is valid UTF-8 string and replace // any un-printable characters with '?' when it's not. char *cleaned = NULL; if (utf8_length(value) == -1) { cleaned = strdup(value); char *chp = cleaned; char ch; while ((ch = *chp)) { if (ch & 0x80) { *chp = '?'; } chp++; } value = cleaned; } valueStr = mEnv->NewStringUTF(value); free(cleaned); if (valueStr == NULL) { mEnv->DeleteLocalRef(nameStr); mEnv->ExceptionClear(); return NO_MEMORY; } mEnv->CallVoidMethod( mClient, mHandleStringTagMethodID, nameStr, valueStr); mEnv->DeleteLocalRef(nameStr); mEnv->DeleteLocalRef(valueStr); return checkAndClearExceptionFromCallback(mEnv, "handleStringTag"); } virtual status_t setMimeType(const char* mimeType) { ALOGV("setMimeType: %s", mimeType); jstring mimeTypeStr; if ((mimeTypeStr = mEnv->NewStringUTF(mimeType)) == NULL) { mEnv->ExceptionClear(); return NO_MEMORY; } mEnv->CallVoidMethod(mClient, mSetMimeTypeMethodID, mimeTypeStr); mEnv->DeleteLocalRef(mimeTypeStr); return checkAndClearExceptionFromCallback(mEnv, "setMimeType"); } virtual bool needStopScan() { jboolean rtn = mEnv->GetBooleanField(mScanner,mNeedStopFileID); return rtn; }private: JNIEnv *mEnv; jobject mClient; jobject mScanner; jmethodID mScanFileMethodID; jmethodID mHandleStringTagMethodID; jmethodID mSetMimeTypeMethodID; jfieldID mNeedStopFileID;};static MediaScanner *getNativeScanner_l(JNIEnv* env, jobject thiz){ return (MediaScanner *) env->GetIntField(thiz, fields.context);}static void setNativeScanner_l(JNIEnv* env, jobject thiz, MediaScanner *s){ env->SetIntField(thiz, fields.context, (int)s);}static voidandroid_media_MediaScanner_processDirectory( JNIEnv *env, jobject thiz, jstring path, jobject client){ ALOGV("processDirectory"); MediaScanner *mp = getNativeScanner_l(env, thiz); if (mp == NULL) { jniThrowException(env, kRunTimeException, "No scanner available"); return; } if (path == NULL) { jniThrowException(env, kIllegalArgumentException, NULL); return; } const char *pathStr = env->GetStringUTFChars(path, NULL); if (pathStr == NULL) { // Out of memory return; } MyMediaScannerClient myClient(env, client,thiz); MediaScanResult result = mp->processDirectory(pathStr, myClient); if (result == MEDIA_SCAN_RESULT_ERROR) { ALOGE("An error occurred while scanning directory '%s'.", pathStr); } env->ReleaseStringUTFChars(path, pathStr);}static voidandroid_media_MediaScanner_processFile( JNIEnv *env, jobject thiz, jstring path, jstring mimeType, jobject client){ ALOGV("processFile"); // Lock already hold by processDirectory MediaScanner *mp = getNativeScanner_l(env, thiz); if (mp == NULL) { jniThrowException(env, kRunTimeException, "No scanner available"); return; } if (path == NULL) { jniThrowException(env, kIllegalArgumentException, NULL); return; } const char *pathStr = env->GetStringUTFChars(path, NULL); if (pathStr == NULL) { // Out of memory return; } const char *mimeTypeStr = (mimeType ? env->GetStringUTFChars(mimeType, NULL) : NULL); if (mimeType && mimeTypeStr == NULL) { // Out of memory // ReleaseStringUTFChars can be called with an exception pending. env->ReleaseStringUTFChars(path, pathStr); return; } MyMediaScannerClient myClient(env, client, thiz); MediaScanResult result = mp->processFile(pathStr, mimeTypeStr, myClient); if (result == MEDIA_SCAN_RESULT_ERROR) { ALOGE("An error occurred while scanning file '%s'.", pathStr); } env->ReleaseStringUTFChars(path, pathStr); if (mimeType) { env->ReleaseStringUTFChars(mimeType, mimeTypeStr); }}static voidandroid_media_MediaScanner_setLocale( JNIEnv *env, jobject thiz, jstring locale){ ALOGV("setLocale"); MediaScanner *mp = getNativeScanner_l(env, thiz); if (mp == NULL) { jniThrowException(env, kRunTimeException, "No scanner available"); return; } if (locale == NULL) { jniThrowException(env, kIllegalArgumentException, NULL); return; } const char *localeStr = env->GetStringUTFChars(locale, NULL); if (localeStr == NULL) { // Out of memory return; } mp->setLocale(localeStr); env->ReleaseStringUTFChars(locale, localeStr);}static jbyteArrayandroid_media_MediaScanner_extractAlbumArt( JNIEnv *env, jobject thiz, jobject fileDescriptor){ ALOGV("extractAlbumArt"); MediaScanner *mp = getNativeScanner_l(env, thiz); if (mp == NULL) { jniThrowException(env, kRunTimeException, "No scanner available"); return NULL; } if (fileDescriptor == NULL) { jniThrowException(env, kIllegalArgumentException, NULL); return NULL; } int fd = jniGetFDFromFileDescriptor(env, fileDescriptor); char* data = mp->extractAlbumArt(fd); if (!data) { return NULL; } long len = *((long*)data); jbyteArray array = env->NewByteArray(len); if (array != NULL) { jbyte* bytes = env->GetByteArrayElements(array, NULL); memcpy(bytes, data + 4, len); env->ReleaseByteArrayElements(array, bytes, 0); }done: free(data); // if NewByteArray() returned NULL, an out-of-memory // exception will have been raised. I just want to // return null in that case. env->ExceptionClear(); return array;}// This function gets a field ID, which in turn causes class initialization.// It is called from a static block in MediaScanner, which won't run until the// first time an instance of this class is used.static voidandroid_media_MediaScanner_native_init(JNIEnv *env){ ALOGV("native_init"); jclass clazz = env->FindClass(kClassMediaScanner); if (clazz == NULL) { return; } fields.context = env->GetFieldID(clazz, "mNativeContext", "I"); if (fields.context == NULL) { return; }}static voidandroid_media_MediaScanner_native_setup(JNIEnv *env, jobject thiz){ ALOGV("native_setup"); MediaScanner *mp = new StagefrightMediaScanner; if (mp == NULL) { jniThrowException(env, kRunTimeException, "Out of memory"); return; } env->SetIntField(thiz, fields.context, (int)mp);}static voidandroid_media_MediaScanner_native_finalize(JNIEnv *env, jobject thiz){ ALOGV("native_finalize"); MediaScanner *mp = getNativeScanner_l(env, thiz); if (mp == 0) { return; } delete mp; setNativeScanner_l(env, thiz, 0);}static JNINativeMethod gMethods[] = { { "processDirectory", "(Ljava/lang/String;Landroid/media/MediaScannerClient;)V", (void *)android_media_MediaScanner_processDirectory }, { "processFile", "(Ljava/lang/String;Ljava/lang/String;Landroid/media/MediaScannerClient;)V", (void *)android_media_MediaScanner_processFile }, { "setLocale", "(Ljava/lang/String;)V", (void *)android_media_MediaScanner_setLocale }, { "extractAlbumArt", "(Ljava/io/FileDescriptor;)[B", (void *)android_media_MediaScanner_extractAlbumArt }, { "native_init", "()V", (void *)android_media_MediaScanner_native_init }, { "native_setup", "()V", (void *)android_media_MediaScanner_native_setup }, { "native_finalize", "()V", (void *)android_media_MediaScanner_native_finalize },};// This function only registers the native methods, and is called from// JNI_OnLoad in android_media_MediaPlayer.cppint register_android_media_MediaScanner(JNIEnv *env){ return AndroidRuntime::registerNativeMethods(env, kClassMediaScanner, gMethods, NELEM(gMethods));}java源码/* * Copyright (C) 2007 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 android.media;import org.xml.sax.Attributes;import org.xml.sax.ContentHandler;import org.xml.sax.SAXException;import android.content.ContentUris;import android.content.ContentValues;import android.content.Context;import android.content.IContentProvider;import android.database.Cursor;import android.database.SQLException;import android.drm.DrmManagerClient;import android.graphics.BitmapFactory;import android.mtp.MtpConstants;import android.net.Uri;import android.os.Environment;import android.os.RemoteException;import android.os.SystemProperties;import android.provider.MediaStore;import android.provider.MediaStore.Audio;import android.provider.MediaStore.Audio.Playlists;import android.provider.MediaStore.Files;import android.provider.MediaStore.Files.FileColumns;import android.provider.MediaStore.Images;import android.provider.MediaStore.Video;import android.provider.Settings;import android.sax.Element;import android.sax.ElementListener;import android.sax.RootElement;import android.text.TextUtils;import android.util.Log;import android.util.Xml;import java.io.BufferedReader;import java.io.File;import java.io.FileDescriptor;import java.io.FileInputStream;import java.io.IOException;import java.io.InputStreamReader;import java.util.ArrayList;import java.util.HashSet;import java.util.Iterator;import java.util.Locale;import libcore.io.ErrnoException;import libcore.io.Libcore;/** * Internal service helper that no-one should use directly. * * The way the scan currently works is: * - The Java MediaScannerService creates a MediaScanner (this class), and calls * MediaScanner.scanDirectories on it. * - scanDirectories() calls the native processDirectory() for each of the specified directories. * - the processDirectory() JNI method wraps the provided mediascanner client in a native * 'MyMediaScannerClient' class, then calls processDirectory() on the native MediaScanner * object (which got created when the Java MediaScanner was created). * - native MediaScanner.processDirectory() calls * doProcessDirectory(), which recurses over the folder, and calls * native MyMediaScannerClient.scanFile() for every file whose extension matches. * - native MyMediaScannerClient.scanFile() calls back on Java MediaScannerClient.scanFile, * which calls doScanFile, which after some setup calls back down to native code, calling * MediaScanner.processFile(). * - MediaScanner.processFile() calls one of several methods, depending on the type of the * file: parseMP3, parseMP4, parseMidi, parseOgg or parseWMA. * - each of these methods gets metadata key/value pairs from the file, and repeatedly * calls native MyMediaScannerClient.handleStringTag, which calls back up to its Java * counterparts in this file. * - Java handleStringTag() gathers the key/value pairs that it's interested in. * - once processFile returns and we're back in Java code in doScanFile(), it calls * Java MyMediaScannerClient.endFile(), which takes all the data that's been * gathered and inserts an entry in to the database. * * In summary: * Java MediaScannerService calls * Java MediaScanner scanDirectories, which calls * Java MediaScanner processDirectory (native method), which calls * native MediaScanner processDirectory, which calls * native MyMediaScannerClient scanFile, which calls * Java MyMediaScannerClient scanFile, which calls * Java MediaScannerClient doScanFile, which calls * Java MediaScanner processFile (native method), which calls * native MediaScanner processFile, which calls * native parseMP3, parseMP4, parseMidi, parseOgg or parseWMA, which calls * native MyMediaScanner handleStringTag, which calls * Java MyMediaScanner handleStringTag. * Once MediaScanner processFile returns, an entry is inserted in to the database. * * The MediaScanner class is not thread-safe, so it should only be used in a single threaded manner. * * {@hide} */public class MediaScanner{ static { System.loadLibrary("media_jni"); native_init(); } private final static String TAG = "MediaScanner"; private static final String[] FILES_PRESCAN_PROJECTION = new String[] { Files.FileColumns._ID, // 0 Files.FileColumns.DATA, // 1 Files.FileColumns.FORMAT, // 2 Files.FileColumns.DATE_MODIFIED, // 3 }; private static final String[] ID_PROJECTION = new String[] { Files.FileColumns._ID, }; private static final int FILES_PRESCAN_ID_COLUMN_INDEX = 0; private static final int FILES_PRESCAN_PATH_COLUMN_INDEX = 1; private static final int FILES_PRESCAN_FORMAT_COLUMN_INDEX = 2; private static final int FILES_PRESCAN_DATE_MODIFIED_COLUMN_INDEX = 3; private static final String[] PLAYLIST_MEMBERS_PROJECTION = new String[] { Audio.Playlists.Members.PLAYLIST_ID, // 0 }; private static final int ID_PLAYLISTS_COLUMN_INDEX = 0; private static final int PATH_PLAYLISTS_COLUMN_INDEX = 1; private static final int DATE_MODIFIED_PLAYLISTS_COLUMN_INDEX = 2; private static final String RINGTONES_DIR = "/ringtones/"; private static final String NOTIFICATIONS_DIR = "/notifications/"; private static final String ALARMS_DIR = "/alarms/"; private static final String MUSIC_DIR = "/music/"; private static final String PODCAST_DIR = "/podcasts/"; private static final String[] ID3_GENRES = { // ID3v1 Genres "Blues", "Classic Rock", "Country", "Dance", "Disco", "Funk", "Grunge", "Hip-Hop", "Jazz", "Metal", "New Age", "Oldies", "Other", "Pop", "R&B", "Rap", "Reggae", "Rock", "Techno", "Industrial", "Alternative", "Ska", "Death Metal", "Pranks", "Soundtrack", "Euro-Techno", "Ambient", "Trip-Hop", "Vocal", "Jazz+Funk", "Fusion", "Trance", "Classical", "Instrumental", "Acid", "House", "Game", "Sound Clip", "Gospel", "Noise", "AlternRock", "Bass", "Soul", "Punk", "Space", "Meditative", "Instrumental Pop", "Instrumental Rock", "Ethnic", "Gothic", "Darkwave", "Techno-Industrial", "Electronic", "Pop-Folk", "Eurodance", "Dream", "Southern Rock", "Comedy", "Cult", "Gangsta", "Top 40", "Christian Rap", "Pop/Funk", "Jungle", "Native American", "Cabaret", "New Wave", "Psychadelic", "Rave", "Showtunes", "Trailer", "Lo-Fi", "Tribal", "Acid Punk", "Acid Jazz", "Polka", "Retro", "Musical", "Rock & Roll", "Hard Rock", // The following genres are Winamp extensions "Folk", "Folk-Rock", "National Folk", "Swing", "Fast Fusion", "Bebob", "Latin", "Revival", "Celtic", "Bluegrass", "Avantgarde", "Gothic Rock", "Progressive Rock", "Psychedelic Rock", "Symphonic Rock", "Slow Rock", "Big Band", "Chorus", "Easy Listening", "Acoustic", "Humour", "Speech", "Chanson", "Opera", "Chamber Music", "Sonata", "Symphony", "Booty Bass", "Primus", "Porn Groove", "Satire", "Slow Jam", "Club", "Tango", "Samba", "Folklore", "Ballad", "Power Ballad", "Rhythmic Soul", "Freestyle", "Duet", "Punk Rock", "Drum Solo", "A capella", "Euro-House", "Dance Hall", // The following ones seem to be fairly widely supported as well "Goa", "Drum & Bass", "Club-House", "Hardcore", "Terror", "Indie", "Britpop", "Negerpunk", "Polsk Punk", "Beat", "Christian Gangsta", "Heavy Metal", "Black Metal", "Crossover", "Contemporary Christian", "Christian Rock", "Merengue", "Salsa", "Thrash Metal", "Anime", "JPop", "Synthpop", // 148 and up don't seem to have been defined yet. }; private int mNativeContext; private Context mContext; private IContentProvider mMediaProvider; private Uri mAudioUri; private Uri mVideoUri; private Uri mImagesUri; private Uri mThumbsUri; private Uri mPlaylistsUri; private Uri mFilesUri; private boolean mProcessPlaylists, mProcessGenres; private int mMtpObjectHandle; private final String mExternalStoragePath; private final boolean mExternalIsEmulated; /** whether to use bulk inserts or individual inserts for each item */ private static final boolean ENABLE_BULK_INSERTS = true; // used when scanning the image database so we know whether we have to prune // old thumbnail files private int mOriginalCount; /** Whether the database had any entries in it before the scan started */ private boolean mWasEmptyPriorToScan = false; /** Whether the scanner has set a default sound for the ringer ringtone. */ private boolean mDefaultRingtoneSet; /** Whether the scanner has set a default sound for the notification ringtone. */ private boolean mDefaultNotificationSet; /** Whether the scanner has set a default sound for the alarm ringtone. */ private boolean mDefaultAlarmSet; /** The filename for the default sound for the ringer ringtone. */ private String mDefaultRingtoneFilename; /** The filename for the default sound for the notification ringtone. */ private String mDefaultNotificationFilename; /** The filename for the default sound for the alarm ringtone. */ private String mDefaultAlarmAlertFilename; /** * The prefix for system properties that define the default sound for * ringtones. Concatenate the name of the setting from Settings * to get the full system property. */ private static final String DEFAULT_RINGTONE_PROPERTY_PREFIX = "ro.config."; // set to true if file path comparisons should be case insensitive. // this should be set when scanning files on a case insensitive file system. private boolean mCaseInsensitivePaths; private final BitmapFactory.Options mBitmapOptions = new BitmapFactory.Options(); private static class FileEntry { long mRowId; String mPath; long mLastModified; int mFormat; boolean mLastModifiedChanged; FileEntry(long rowId, String path, long lastModified, int format) { mRowId = rowId; mPath = path; mLastModified = lastModified; mFormat = format; mLastModifiedChanged = false; } @Override public String toString() { return mPath + " mRowId: " + mRowId; } } private static class PlaylistEntry { String path; long bestmatchid; int bestmatchlevel; } private ArrayList<PlaylistEntry> mPlaylistEntries = new ArrayList<PlaylistEntry>(); private MediaInserter mMediaInserter; private ArrayList<FileEntry> mPlayLists; private DrmManagerClient mDrmManagerClient = null; public MediaScanner(Context c) { native_setup(); mContext = c; mBitmapOptions.inSampleSize = 1; mBitmapOptions.inJustDecodeBounds = true; setDefaultRingtoneFileNames(); mExternalStoragePath = Environment.getExternalStorageDirectory().getAbsolutePath(); mExternalIsEmulated = Environment.isExternalStorageEmulated(); //mClient.testGenreNameConverter(); } private void setDefaultRingtoneFileNames() { mDefaultRingtoneFilename = SystemProperties.get(DEFAULT_RINGTONE_PROPERTY_PREFIX + Settings.System.RINGTONE); mDefaultNotificationFilename = SystemProperties.get(DEFAULT_RINGTONE_PROPERTY_PREFIX + Settings.System.NOTIFICATION_SOUND); mDefaultAlarmAlertFilename = SystemProperties.get(DEFAULT_RINGTONE_PROPERTY_PREFIX + Settings.System.ALARM_ALERT); } private final MyMediaScannerClient mClient = new MyMediaScannerClient(); private boolean isDrmEnabled() { String prop = SystemProperties.get("drm.service.enabled"); return prop != null && prop.equals("true"); } private class MyMediaScannerClient implements MediaScannerClient { private String mArtist; private String mAlbumArtist; // use this if mArtist is missing private String mAlbum; private String mTitle; private String mComposer; private String mGenre; private String mMimeType; private int mFileType; private int mTrack; private int mYear; private int mDuration; private String mPath; private long mLastModified; private long mFileSize; private String mWriter; private int mCompilation; private boolean mIsDrm; private boolean mNoMedia; // flag to suppress file from appearing in media tables private int mWidth; private int mHeight; public FileEntry beginFile(String path, String mimeType, long lastModified, long fileSize, boolean isDirectory, boolean noMedia) { mMimeType = mimeType; mFileType = 0; mFileSize = fileSize; if (!isDirectory) { if (!noMedia && isNoMediaFile(path)) { noMedia = true; } mNoMedia = noMedia; // try mimeType first, if it is specified if (mimeType != null) { mFileType = MediaFile.getFileTypeForMimeType(mimeType); } // if mimeType was not specified, compute file type based on file extension. if (mFileType == 0) { MediaFile.MediaFileType mediaFileType = MediaFile.getFileType(path); if (mediaFileType != null) { mFileType = mediaFileType.fileType; if (mMimeType == null) { mMimeType = mediaFileType.mimeType; } } } if (isDrmEnabled() && MediaFile.isDrmFileType(mFileType)) { mFileType = getFileTypeFromDrm(path); } } FileEntry entry = makeEntryFor(path); // add some slack to avoid a rounding error long delta = (entry != null) ? (lastModified - entry.mLastModified) : 0; boolean wasModified = delta > 1 || delta < -1; if (entry == null || wasModified) { if (wasModified) { entry.mLastModified = lastModified; } else { entry = new FileEntry(0, path, lastModified, (isDirectory ? MtpConstants.FORMAT_ASSOCIATION : 0)); } entry.mLastModifiedChanged = true; } if (mProcessPlaylists && MediaFile.isPlayListFileType(mFileType)) { mPlayLists.add(entry); // we don't process playlists in the main scan, so return null return null; } // clear all the metadata mArtist = null; mAlbumArtist = null; mAlbum = null; mTitle = null; mComposer = null; mGenre = null; mTrack = 0; mYear = 0; mDuration = 0; mPath = path; mLastModified = lastModified; mWriter = null; mCompilation = 0; mIsDrm = false; mWidth = 0; mHeight = 0; return entry; } @Override public void scanFile(String path, long lastModified, long fileSize, boolean isDirectory, boolean noMedia) { // This is the callback funtion from native codes. // Log.v(TAG, "scanFile: "+path); doScanFile(path, null, lastModified, fileSize, isDirectory, false, noMedia); } public Uri doScanFile(String path, String mimeType, long lastModified, long fileSize, boolean isDirectory, boolean scanAlways, boolean noMedia) { Uri result = null;// long t1 = System.currentTimeMillis(); try { FileEntry entry = beginFile(path, mimeType, lastModified, fileSize, isDirectory, noMedia); // if this file was just inserted via mtp, set the rowid to zero // (even though it already exists in the database), to trigger // the correct code path for updating its entry if (mMtpObjectHandle != 0) { entry.mRowId = 0; } // rescan for metadata if file was modified since last scan if (entry != null && (entry.mLastModifiedChanged || scanAlways)) { if (noMedia) { result = endFile(entry, false, false, false, false, false); } else { String lowpath = path.toLowerCase(); boolean ringtones = (lowpath.indexOf(RINGTONES_DIR) > 0); boolean notifications = (lowpath.indexOf(NOTIFICATIONS_DIR) > 0); boolean alarms = (lowpath.indexOf(ALARMS_DIR) > 0); boolean podcasts = (lowpath.indexOf(PODCAST_DIR) > 0); boolean music = (lowpath.indexOf(MUSIC_DIR) > 0) || (!ringtones && !notifications && !alarms && !podcasts); boolean isaudio = MediaFile.isAudioFileType(mFileType); boolean isvideo = MediaFile.isVideoFileType(mFileType); boolean isimage = MediaFile.isImageFileType(mFileType); if (isaudio || isvideo || isimage) { if (mExternalIsEmulated && path.startsWith(mExternalStoragePath)) { // try to rewrite the path to bypass the sd card fuse layer String directPath = Environment.getMediaStorageDirectory() + path.substring(mExternalStoragePath.length()); File f = new File(directPath); if (f.exists()) { path = directPath; } } } // we only extract metadata for audio and video files if (isaudio || isvideo) { processFile(path, mimeType, this); } if (isimage) { processImageFile(path); } result = endFile(entry, ringtones, notifications, alarms, music, podcasts); } } } catch (RemoteException e) { Log.e(TAG, "RemoteException in MediaScanner.scanFile()", e); }// long t2 = System.currentTimeMillis();// Log.v(TAG, "scanFile: " + path + " took " + (t2-t1)); return result; } private int parseSubstring(String s, int start, int defaultValue) { int length = s.length(); if (start == length) return defaultValue; char ch = s.charAt(start++); // return defaultValue if we have no integer at all if (ch < '0' || ch > '9') return defaultValue; int result = ch - '0'; while (start < length) { ch = s.charAt(start++); if (ch < '0' || ch > '9') return result; result = result * 10 + (ch - '0'); } return result; } public void handleStringTag(String name, String value) { if (name.equalsIgnoreCase("title") || name.startsWith("title;")) { // Don't trim() here, to preserve the special \001 character // used to force sorting. The media provider will trim() before // inserting the title in to the database. mTitle = value; } else if (name.equalsIgnoreCase("artist") || name.startsWith("artist;")) { mArtist = value.trim(); } else if (name.equalsIgnoreCase("albumartist") || name.startsWith("albumartist;") || name.equalsIgnoreCase("band") || name.startsWith("band;")) { mAlbumArtist = value.trim(); } else if (name.equalsIgnoreCase("album") || name.startsWith("album;")) { mAlbum = value.trim(); } else if (name.equalsIgnoreCase("composer") || name.startsWith("composer;")) { mComposer = value.trim(); } else if (mProcessGenres && (name.equalsIgnoreCase("genre") || name.startsWith("genre;"))) { mGenre = getGenreName(value); } else if (name.equalsIgnoreCase("year") || name.startsWith("year;")) { mYear = parseSubstring(value, 0, 0); } else if (name.equalsIgnoreCase("tracknumber") || name.startsWith("tracknumber;")) { // track number might be of the form "2/12" // we just read the number before the slash int num = parseSubstring(value, 0, 0); mTrack = (mTrack / 1000) * 1000 + num; } else if (name.equalsIgnoreCase("discnumber") || name.equals("set") || name.startsWith("set;")) { // set number might be of the form "1/3" // we just read the number before the slash int num = parseSubstring(value, 0, 0); mTrack = (num * 1000) + (mTrack % 1000); } else if (name.equalsIgnoreCase("duration")) { mDuration = parseSubstring(value, 0, 0); } else if (name.equalsIgnoreCase("writer") || name.startsWith("writer;")) { mWriter = value.trim(); } else if (name.equalsIgnoreCase("compilation")) { mCompilation = parseSubstring(value, 0, 0); } else if (name.equalsIgnoreCase("isdrm")) { mIsDrm = (parseSubstring(value, 0, 0) == 1); } else if (name.equalsIgnoreCase("width")) { mWidth = parseSubstring(value, 0, 0); } else if (name.equalsIgnoreCase("height")) { mHeight = parseSubstring(value, 0, 0); } else { //Log.v(TAG, "unknown tag: " + name + " (" + mProcessGenres + ")"); } } private boolean convertGenreCode(String input, String expected) { String output = getGenreName(input); if (output.equals(expected)) { return true; } else { Log.d(TAG, "'" + input + "' -> '" + output + "', expected '" + expected + "'"); return false; } } private void testGenreNameConverter() { convertGenreCode("2", "Country"); convertGenreCode("(2)", "Country"); convertGenreCode("(2", "(2"); convertGenreCode("2 Foo", "Country"); convertGenreCode("(2) Foo", "Country"); convertGenreCode("(2 Foo", "(2 Foo"); convertGenreCode("2Foo", "2Foo"); convertGenreCode("(2)Foo", "Country"); convertGenreCode("200 Foo", "Foo"); convertGenreCode("(200) Foo", "Foo"); convertGenreCode("200Foo", "200Foo"); convertGenreCode("(200)Foo", "Foo"); convertGenreCode("200)Foo", "200)Foo"); convertGenreCode("200) Foo", "200) Foo"); } public String getGenreName(String genreTagValue) { if (genreTagValue == null) { return null; } final int length = genreTagValue.length(); if (length > 0) { boolean parenthesized = false; StringBuffer number = new StringBuffer(); int i = 0; for (; i < length; ++i) { char c = genreTagValue.charAt(i); if (i == 0 && c == '(') { parenthesized = true; } else if (Character.isDigit(c)) { number.append(c); } else { break; } } char charAfterNumber = i < length ? genreTagValue.charAt(i) : ' '; if ((parenthesized && charAfterNumber == ')') || !parenthesized && Character.isWhitespace(charAfterNumber)) { try { short genreIndex = Short.parseShort(number.toString()); if (genreIndex >= 0) { if (genreIndex < ID3_GENRES.length) { return ID3_GENRES[genreIndex]; } else if (genreIndex == 0xFF) { return null; } else if (genreIndex < 0xFF && (i + 1) < length) { // genre is valid but unknown, // if there is a string after the value we take it if (parenthesized && charAfterNumber == ')') { i++; } String ret = genreTagValue.substring(i).trim(); if (ret.length() != 0) { return ret; } } else { // else return the number, without parentheses return number.toString(); } } } catch (NumberFormatException e) { } } } return genreTagValue; } private void processImageFile(String path) { try { mBitmapOptions.outWidth = 0; mBitmapOptions.outHeight = 0; BitmapFactory.decodeFile(path, mBitmapOptions); mWidth = mBitmapOptions.outWidth; mHeight = mBitmapOptions.outHeight; } catch (Throwable th) { // ignore; } } public void setMimeType(String mimeType) { if ("audio/mp4".equals(mMimeType) && mimeType.startsWith("video")) { // for feature parity with Donut, we force m4a files to keep the // audio/mp4 mimetype, even if they are really "enhanced podcasts" // with a video track return; } mMimeType = mimeType; mFileType = MediaFile.getFileTypeForMimeType(mimeType); } /** * Formats the data into a values array suitable for use with the Media * Content Provider. * * @return a map of values */ private ContentValues toValues() { ContentValues map = new ContentValues(); map.put(MediaStore.MediaColumns.DATA, mPath); map.put(MediaStore.MediaColumns.TITLE, mTitle); map.put(MediaStore.MediaColumns.DATE_MODIFIED, mLastModified); map.put(MediaStore.MediaColumns.SIZE, mFileSize); map.put(MediaStore.MediaColumns.MIME_TYPE, mMimeType); map.put(MediaStore.MediaColumns.IS_DRM, mIsDrm); String resolution = null; if (mWidth > 0 && mHeight > 0) { map.put(MediaStore.MediaColumns.WIDTH, mWidth); map.put(MediaStore.MediaColumns.HEIGHT, mHeight); resolution = mWidth + "x" + mHeight; } if (!mNoMedia) { if (MediaFile.isVideoFileType(mFileType)) { map.put(Video.Media.ARTIST, (mArtist != null && mArtist.length() > 0 ? mArtist : MediaStore.UNKNOWN_STRING)); map.put(Video.Media.ALBUM, (mAlbum != null && mAlbum.length() > 0 ? mAlbum : MediaStore.UNKNOWN_STRING)); map.put(Video.Media.DURATION, mDuration); if (resolution != null) { map.put(Video.Media.RESOLUTION, resolution); } } else if (MediaFile.isImageFileType(mFileType)) { // FIXME - add DESCRIPTION } else if (MediaFile.isAudioFileType(mFileType)) { map.put(Audio.Media.ARTIST, (mArtist != null && mArtist.length() > 0) ? mArtist : MediaStore.UNKNOWN_STRING); map.put(Audio.Media.ALBUM_ARTIST, (mAlbumArtist != null && mAlbumArtist.length() > 0) ? mAlbumArtist : null); map.put(Audio.Media.ALBUM, (mAlbum != null && mAlbum.length() > 0) ? mAlbum : MediaStore.UNKNOWN_STRING); map.put(Audio.Media.COMPOSER, mComposer); map.put(Audio.Media.GENRE, mGenre); if (mYear != 0) { map.put(Audio.Media.YEAR, mYear); } map.put(Audio.Media.TRACK, mTrack); map.put(Audio.Media.DURATION, mDuration); map.put(Audio.Media.COMPILATION, mCompilation); } } return map; } private Uri endFile(FileEntry entry, boolean ringtones, boolean notifications, boolean alarms, boolean music, boolean podcasts) throws RemoteException { // update database // use album artist if artist is missing if (mArtist == null || mArtist.length() == 0) { mArtist = mAlbumArtist; } ContentValues values = toValues(); String title = values.getAsString(MediaStore.MediaColumns.TITLE); if (title == null || TextUtils.isEmpty(title.trim())) { title = MediaFile.getFileTitle(values.getAsString(MediaStore.MediaColumns.DATA)); values.put(MediaStore.MediaColumns.TITLE, title); } String album = values.getAsString(Audio.Media.ALBUM); if (MediaStore.UNKNOWN_STRING.equals(album)) { album = values.getAsString(MediaStore.MediaColumns.DATA); // extract last path segment before file name int lastSlash = album.lastIndexOf('/'); if (lastSlash >= 0) { int previousSlash = 0; while (true) { int idx = album.indexOf('/', previousSlash + 1); if (idx < 0 || idx >= lastSlash) { break; } previousSlash = idx; } if (previousSlash != 0) { album = album.substring(previousSlash + 1, lastSlash); values.put(Audio.Media.ALBUM, album); } } } long rowId = entry.mRowId; if (MediaFile.isAudioFileType(mFileType) && (rowId == 0 || mMtpObjectHandle != 0)) { // Only set these for new entries. For existing entries, they // may have been modified later, and we want to keep the current // values so that custom ringtones still show up in the ringtone // picker. values.put(Audio.Media.IS_RINGTONE, ringtones); values.put(Audio.Media.IS_NOTIFICATION, notifications); values.put(Audio.Media.IS_ALARM, alarms); values.put(Audio.Media.IS_MUSIC, music); values.put(Audio.Media.IS_PODCAST, podcasts); } else if (mFileType == MediaFile.FILE_TYPE_JPEG && !mNoMedia) { ExifInterface exif = null; try { exif = new ExifInterface(entry.mPath); } catch (IOException ex) { // exif is null } if (exif != null) { float[] latlng = new float[2]; if (exif.getLatLong(latlng)) { values.put(Images.Media.LATITUDE, latlng[0]); values.put(Images.Media.LONGITUDE, latlng[1]); } long time = exif.getGpsDateTime(); if (time != -1) { values.put(Images.Media.DATE_TAKEN, time); } else { // If no time zone information is available, we should consider using // EXIF local time as taken time if the difference between file time // and EXIF local time is not less than 1 Day, otherwise MediaProvider // will use file time as taken time. time = exif.getDateTime(); if (time != -1 && Math.abs(mLastModified * 1000 - time) >= 86400000) { values.put(Images.Media.DATE_TAKEN, time); } } int orientation = exif.getAttributeInt( ExifInterface.TAG_ORIENTATION, -1); if (orientation != -1) { // We only recognize a subset of orientation tag values. int degree; switch(orientation) { case ExifInterface.ORIENTATION_ROTATE_90: degree = 90; break; case ExifInterface.ORIENTATION_ROTATE_180: degree = 180; break; case ExifInterface.ORIENTATION_ROTATE_270: degree = 270; break; default: degree = 0; break; } values.put(Images.Media.ORIENTATION, degree); } } } Uri tableUri = mFilesUri; MediaInserter inserter = mMediaInserter; if (!mNoMedia) { if (MediaFile.isVideoFileType(mFileType)) { tableUri = mVideoUri; } else if (MediaFile.isImageFileType(mFileType)) { tableUri = mImagesUri; } else if (MediaFile.isAudioFileType(mFileType)) { tableUri = mAudioUri; } } Uri result = null; boolean needToSetSettings = false; if (rowId == 0) { if (mMtpObjectHandle != 0) { values.put(MediaStore.MediaColumns.MEDIA_SCANNER_NEW_OBJECT_ID, mMtpObjectHandle); } if (tableUri == mFilesUri) { int format = entry.mFormat; if (format == 0) { format = MediaFile.getFormatCode(entry.mPath, mMimeType); } values.put(Files.FileColumns.FORMAT, format); } // Setting a flag in order not to use bulk insert for the file related with // notifications, ringtones, and alarms, because the rowId of the inserted file is // needed. if (mWasEmptyPriorToScan) { if (notifications && !mDefaultNotificationSet) { if (TextUtils.isEmpty(mDefaultNotificationFilename) || doesPathHaveFilename(entry.mPath, mDefaultNotificationFilename)) { needToSetSettings = true; } } else if (ringtones && !mDefaultRingtoneSet) { if (TextUtils.isEmpty(mDefaultRingtoneFilename) || doesPathHaveFilename(entry.mPath, mDefaultRingtoneFilename)) { needToSetSettings = true; } } else if (alarms && !mDefaultAlarmSet) { if (TextUtils.isEmpty(mDefaultAlarmAlertFilename) || doesPathHaveFilename(entry.mPath, mDefaultAlarmAlertFilename)) { needToSetSettings = true; } } } // New file, insert it. // Directories need to be inserted before the files they contain, so they // get priority when bulk inserting. // If the rowId of the inserted file is needed, it gets inserted immediately, // bypassing the bulk inserter. if (inserter == null || needToSetSettings) { result = mMediaProvider.insert(tableUri, values); } else if (entry.mFormat == MtpConstants.FORMAT_ASSOCIATION) { inserter.insertwithPriority(tableUri, values); } else { inserter.insert(tableUri, values); } if (result != null) { rowId = ContentUris.parseId(result); entry.mRowId = rowId; } } else { // updated file result = ContentUris.withAppendedId(tableUri, rowId); // path should never change, and we want to avoid replacing mixed cased paths // with squashed lower case paths values.remove(MediaStore.MediaColumns.DATA); int mediaType = 0; if (!MediaScanner.isNoMediaPath(entry.mPath)) { int fileType = MediaFile.getFileTypeForMimeType(mMimeType); if (MediaFile.isAudioFileType(fileType)) { mediaType = FileColumns.MEDIA_TYPE_AUDIO; } else if (MediaFile.isVideoFileType(fileType)) { mediaType = FileColumns.MEDIA_TYPE_VIDEO; } else if (MediaFile.isImageFileType(fileType)) { mediaType = FileColumns.MEDIA_TYPE_IMAGE; } else if (MediaFile.isPlayListFileType(fileType)) { mediaType = FileColumns.MEDIA_TYPE_PLAYLIST; } values.put(FileColumns.MEDIA_TYPE, mediaType); } mMediaProvider.update(result, values, null, null); } if(needToSetSettings) { if (notifications) { setSettingIfNotSet(Settings.System.NOTIFICATION_SOUND, tableUri, rowId); mDefaultNotificationSet = true; } else if (ringtones) { setSettingIfNotSet(Settings.System.RINGTONE, tableUri, rowId); mDefaultRingtoneSet = true; } else if (alarms) { setSettingIfNotSet(Settings.System.ALARM_ALERT, tableUri, rowId); mDefaultAlarmSet = true; } } return result; } private boolean doesPathHaveFilename(String path, String filename) { int pathFilenameStart = path.lastIndexOf(File.separatorChar) + 1; int filenameLength = filename.length(); return path.regionMatches(pathFilenameStart, filename, 0, filenameLength) && pathFilenameStart + filenameLength == path.length(); } private void setSettingIfNotSet(String settingName, Uri uri, long rowId) { String existingSettingValue = Settings.System.getString(mContext.getContentResolver(), settingName); if (TextUtils.isEmpty(existingSettingValue)) { // Set the setting to the given URI Settings.System.putString(mContext.getContentResolver(), settingName, ContentUris.withAppendedId(uri, rowId).toString()); } } private int getFileTypeFromDrm(String path) { if (!isDrmEnabled()) { return 0; } int resultFileType = 0; if (mDrmManagerClient == null) { mDrmManagerClient = new DrmManagerClient(mContext); } if (mDrmManagerClient.canHandle(path, null)) { String drmMimetype = mDrmManagerClient.getOriginalMimeType(path); if (drmMimetype != null) { mMimeType = drmMimetype; resultFileType = MediaFile.getFileTypeForMimeType(drmMimetype); } } return resultFileType; } }; // end of anonymous MediaScannerClient instance private void prescan(String filePath, boolean prescanFiles) throws RemoteException { Cursor c = null; String where = null; String[] selectionArgs = null; if (mPlayLists == null) { mPlayLists = new ArrayList<FileEntry>(); } else { mPlayLists.clear(); } if (filePath != null) { // query for only one file where = MediaStore.Files.FileColumns._ID + ">?" + " AND " + Files.FileColumns.DATA + "=?"; selectionArgs = new String[] { "", filePath }; } else { where = MediaStore.Files.FileColumns._ID + ">?"; selectionArgs = new String[] { "" }; } // Tell the provider to not delete the file. // If the file is truly gone the delete is unnecessary, and we want to avoid // accidentally deleting files that are really there (this may happen if the // filesystem is mounted and unmounted while the scanner is running). Uri.Builder builder = mFilesUri.buildUpon(); builder.appendQueryParameter(MediaStore.PARAM_DELETE_DATA, "false"); MediaBulkDeleter deleter = new MediaBulkDeleter(mMediaProvider, builder.build()); // Build the list of files from the content provider try { if (prescanFiles) { // First read existing files from the files table. // Because we'll be deleting entries for missing files as we go, // we need to query the database in small batches, to avoid problems // with CursorWindow positioning. long lastId = Long.MIN_VALUE; Uri limitUri = mFilesUri.buildUpon().appendQueryParameter("limit", "1000").build(); mWasEmptyPriorToScan = true; while (true) { selectionArgs[0] = "" + lastId; if (c != null) { c.close(); c = null; } c = mMediaProvider.query(limitUri, FILES_PRESCAN_PROJECTION, where, selectionArgs, MediaStore.Files.FileColumns._ID, null); if (c == null) { break; } int num = c.getCount(); if (num == 0) { break; } mWasEmptyPriorToScan = false; while (c.moveToNext()) { long rowId = c.getLong(FILES_PRESCAN_ID_COLUMN_INDEX); String path = c.getString(FILES_PRESCAN_PATH_COLUMN_INDEX); int format = c.getInt(FILES_PRESCAN_FORMAT_COLUMN_INDEX); long lastModified = c.getLong(FILES_PRESCAN_DATE_MODIFIED_COLUMN_INDEX); lastId = rowId; // Only consider entries with absolute path names. // This allows storing URIs in the database without the // media scanner removing them. if (path != null && path.startsWith("/")) { boolean exists = false; try { exists = Libcore.os.access(path, libcore.io.OsConstants.F_OK); } catch (ErrnoException e1) { } if (!exists && !MtpConstants.isAbstractObject(format)) { // do not delete missing playlists, since they may have been // modified by the user. // The user can delete them in the media player instead. // instead, clear the path and lastModified fields in the row MediaFile.MediaFileType mediaFileType = MediaFile.getFileType(path); int fileType = (mediaFileType == null ? 0 : mediaFileType.fileType); if (!MediaFile.isPlayListFileType(fileType)) { deleter.delete(rowId); if (path.toLowerCase(Locale.US).endsWith("/.nomedia")) { deleter.flush(); String parent = new File(path).getParent(); mMediaProvider.call(MediaStore.UNHIDE_CALL, parent, null); } } } } } } } } finally { if (c != null) { c.close(); } deleter.flush(); } // compute original size of images mOriginalCount = 0; c = mMediaProvider.query(mImagesUri, ID_PROJECTION, null, null, null, null); if (c != null) { mOriginalCount = c.getCount(); c.close(); } } private boolean inScanDirectory(String path, String[] directories) { for (int i = 0; i < directories.length; i++) { String directory = directories[i]; if (path.startsWith(directory)) { return true; } } return false; } private void pruneDeadThumbnailFiles() { HashSet<String> existingFiles = new HashSet<String>(); String directory = "/sdcard/DCIM/.thumbnails"; String [] files = (new File(directory)).list(); if (files == null) files = new String[0]; for (int i = 0; i < files.length; i++) { String fullPathString = directory + "/" + files[i]; existingFiles.add(fullPathString); } try { Cursor c = mMediaProvider.query( mThumbsUri, new String [] { "_data" }, null, null, null, null); Log.v(TAG, "pruneDeadThumbnailFiles... " + c); if (c != null && c.moveToFirst()) { do { String fullPathString = c.getString(0); existingFiles.remove(fullPathString); } while (c.moveToNext()); } for (String fileToDelete : existingFiles) { if (false) Log.v(TAG, "fileToDelete is " + fileToDelete); try { (new File(fileToDelete)).delete(); } catch (SecurityException ex) { } } Log.v(TAG, "/pruneDeadThumbnailFiles... " + c); if (c != null) { c.close(); } } catch (RemoteException e) { // We will soon be killed... } } static class MediaBulkDeleter { StringBuilder whereClause = new StringBuilder(); ArrayList<String> whereArgs = new ArrayList<String>(100); IContentProvider mProvider; Uri mBaseUri; public MediaBulkDeleter(IContentProvider provider, Uri baseUri) { mProvider = provider; mBaseUri = baseUri; } public void delete(long id) throws RemoteException { if (whereClause.length() != 0) { whereClause.append(","); } whereClause.append("?"); whereArgs.add("" + id); if (whereArgs.size() > 100) { flush(); } } public void flush() throws RemoteException { int size = whereArgs.size(); if (size > 0) { String [] foo = new String [size]; foo = whereArgs.toArray(foo); int numrows = mProvider.delete(mBaseUri, MediaStore.MediaColumns._ID + " IN (" + whereClause.toString() + ")", foo); //Log.i("@@@@@@@@@", "rows deleted: " + numrows); whereClause.setLength(0); whereArgs.clear(); } } } private void postscan(String[] directories) throws RemoteException { // handle playlists last, after we know what media files are on the storage. if (mProcessPlaylists) { processPlayLists(); } if (mOriginalCount == 0 && mImagesUri.equals(Images.Media.getContentUri("external"))) pruneDeadThumbnailFiles(); // allow GC to clean up mPlayLists = null; mMediaProvider = null; } private void initialize(String volumeName) { mMediaProvider = mContext.getContentResolver().acquireProvider("media"); mAudioUri = Audio.Media.getContentUri(volumeName); mVideoUri = Video.Media.getContentUri(volumeName); mImagesUri = Images.Media.getContentUri(volumeName); mThumbsUri = Images.Thumbnails.getContentUri(volumeName); mFilesUri = Files.getContentUri(volumeName); if (!volumeName.equals("internal")) { // we only support playlists on external media mProcessPlaylists = true; mProcessGenres = true; mPlaylistsUri = Playlists.getContentUri(volumeName); mCaseInsensitivePaths = true; } } private boolean mStopScan = false;//jni will read it to check if need stop scan private Object mLock = new Object(); private int mScanCount = 0; //for mediaprovider to stop all scan public void stopScan() { synchronized(mLock) { if(mScanCount > 0) mStopScan = true; } } private void startScan() { synchronized(mLock) { mScanCount ++; } } private void exitScan() { synchronized(mLock) { mScanCount --; if( mScanCount == 0 ){ if(mStopScan == true) mStopScan = false; } } } public void scanDirectories(String[] directories, String volumeName) { try { startScan(); long start = System.currentTimeMillis(); initialize(volumeName); prescan(null, true); long prescan = System.currentTimeMillis(); if (ENABLE_BULK_INSERTS) { // create MediaInserter for bulk inserts mMediaInserter = new MediaInserter(mMediaProvider, 500); } for (int i = 0; i < directories.length; i++) { synchronized(mLock){ if(mStopScan == true) { break; } } processDirectory(directories[i], mClient); } if (ENABLE_BULK_INSERTS) { // flush remaining inserts mMediaInserter.flushAll(); mMediaInserter = null; } long scan = System.currentTimeMillis(); postscan(directories); long end = System.currentTimeMillis(); if (false) { Log.d(TAG, " prescan time: " + (prescan - start) + "ms\n"); Log.d(TAG, " scan time: " + (scan - prescan) + "ms\n"); Log.d(TAG, "postscan time: " + (end - scan) + "ms\n"); Log.d(TAG, " total time: " + (end - start) + "ms\n"); } } catch (SQLException e) { // this might happen if the SD card is removed while the media scanner is running Log.e(TAG, "SQLException in MediaScanner.scan()", e); } catch (UnsupportedOperationException e) { // this might happen if the SD card is removed while the media scanner is running Log.e(TAG, "UnsupportedOperationException in MediaScanner.scan()", e); } catch (RemoteException e) { Log.e(TAG, "RemoteException in MediaScanner.scan()", e); } exitScan(); } // this function is used to scan a single file public Uri scanSingleFile(String path, String volumeName, String mimeType) { try { initialize(volumeName); prescan(path, true); File file = new File(path); // lastModified is in milliseconds on Files. long lastModifiedSeconds = file.lastModified() / 1000; // always scan the file, so we can return the content://media Uri for existing files return mClient.doScanFile(path, mimeType, lastModifiedSeconds, file.length(), false, true, false); } catch (RemoteException e) { Log.e(TAG, "RemoteException in MediaScanner.scanFile()", e); return null; } } private static boolean isNoMediaFile(String path) { File file = new File(path); if (file.isDirectory()) return false; // special case certain file names // I use regionMatches() instead of substring() below // to avoid memory allocation int lastSlash = path.lastIndexOf('/'); if (lastSlash >= 0 && lastSlash + 2 < path.length()) { // ignore those ._* files created by MacOS if (path.regionMatches(lastSlash + 1, "._", 0, 2)) { return true; } // ignore album art files created by Windows Media Player: // Folder.jpg, AlbumArtSmall.jpg, AlbumArt_{...}_Large.jpg // and AlbumArt_{...}_Small.jpg if (path.regionMatches(true, path.length() - 4, ".jpg", 0, 4)) { if (path.regionMatches(true, lastSlash + 1, "AlbumArt_{", 0, 10) || path.regionMatches(true, lastSlash + 1, "AlbumArt.", 0, 9)) { return true; } int length = path.length() - lastSlash - 1; if ((length == 17 && path.regionMatches( true, lastSlash + 1, "AlbumArtSmall", 0, 13)) || (length == 10 && path.regionMatches(true, lastSlash + 1, "Folder", 0, 6))) { return true; } } } return false; } public static boolean isNoMediaPath(String path) { if (path == null) return false; // return true if file or any parent directory has name starting with a dot if (path.indexOf("/.") >= 0) return true; // now check to see if any parent directories have a ".nomedia" file // start from 1 so we don't bother checking in the root directory int offset = 1; while (offset >= 0) { int slashIndex = path.indexOf('/', offset); if (slashIndex > offset) { slashIndex++; // move past slash File file = new File(path.substring(0, slashIndex) + ".nomedia"); if (file.exists()) { // we have a .nomedia in one of the parent directories return true; } } offset = slashIndex; } return isNoMediaFile(path); } public void scanMtpFile(String path, String volumeName, int objectHandle, int format) { initialize(volumeName); MediaFile.MediaFileType mediaFileType = MediaFile.getFileType(path); int fileType = (mediaFileType == null ? 0 : mediaFileType.fileType); File file = new File(path); long lastModifiedSeconds = file.lastModified() / 1000; if (!MediaFile.isAudioFileType(fileType) && !MediaFile.isVideoFileType(fileType) && !MediaFile.isImageFileType(fileType) && !MediaFile.isPlayListFileType(fileType) && !MediaFile.isDrmFileType(fileType)) { // no need to use the media scanner, but we need to update last modified and file size ContentValues values = new ContentValues(); values.put(Files.FileColumns.SIZE, file.length()); values.put(Files.FileColumns.DATE_MODIFIED, lastModifiedSeconds); try { String[] whereArgs = new String[] { Integer.toString(objectHandle) }; mMediaProvider.update(Files.getMtpObjectsUri(volumeName), values, "_id=?", whereArgs); } catch (RemoteException e) { Log.e(TAG, "RemoteException in scanMtpFile", e); } return; } mMtpObjectHandle = objectHandle; Cursor fileList = null; try { if (MediaFile.isPlayListFileType(fileType)) { // build file cache so we can look up tracks in the playlist prescan(null, true); FileEntry entry = makeEntryFor(path); if (entry != null) { fileList = mMediaProvider.query(mFilesUri, FILES_PRESCAN_PROJECTION, null, null, null, null); processPlayList(entry, fileList); } } else { // MTP will create a file entry for us so we don't want to do it in prescan prescan(path, false); // always scan the file, so we can return the content://media Uri for existing files mClient.doScanFile(path, mediaFileType.mimeType, lastModifiedSeconds, file.length(), (format == MtpConstants.FORMAT_ASSOCIATION), true, isNoMediaPath(path)); } } catch (RemoteException e) { Log.e(TAG, "RemoteException in MediaScanner.scanFile()", e); } finally { mMtpObjectHandle = 0; if (fileList != null) { fileList.close(); } } } FileEntry makeEntryFor(String path) { String where; String[] selectionArgs; Cursor c = null; try { boolean hasWildCards = path.contains("_") || path.contains("%"); if (hasWildCards || !mCaseInsensitivePaths) { // if there are wildcard characters in the path, the "like" match // will be slow, and it's worth trying an "=" comparison // first, since in most cases the case will match. // Also, we shouldn't do a "like" match on case-sensitive filesystems where = Files.FileColumns.DATA + "=?"; selectionArgs = new String[] { path }; } else { // if there are no wildcard characters in the path, then the "like" // match will be just as fast as the "=" case, because of the index where = "_data LIKE ?1 AND lower(_data)=lower(?1)"; selectionArgs = new String[] { path }; } c = mMediaProvider.query(mFilesUri, FILES_PRESCAN_PROJECTION, where, selectionArgs, null, null); if (!c.moveToFirst() && hasWildCards && mCaseInsensitivePaths) { // Try again with case-insensitive match. This will be slower, especially // if the path contains wildcard characters. // The 'like' makes it use the index, the 'lower()' makes it correct // when the path contains sqlite wildcard characters, where = "_data LIKE ?1 AND lower(_data)=lower(?1)"; selectionArgs = new String[] { path }; c.close(); c = mMediaProvider.query(mFilesUri, FILES_PRESCAN_PROJECTION, where, selectionArgs, null, null); // TODO update the path in the db with the correct case so the fast // path works next time? } if (c.moveToFirst()) { long rowId = c.getLong(FILES_PRESCAN_ID_COLUMN_INDEX); int format = c.getInt(FILES_PRESCAN_FORMAT_COLUMN_INDEX); long lastModified = c.getLong(FILES_PRESCAN_DATE_MODIFIED_COLUMN_INDEX); return new FileEntry(rowId, path, lastModified, format); } } catch (RemoteException e) { } finally { if (c != null) { c.close(); } } return null; } // returns the number of matching file/directory names, starting from the right private int matchPaths(String path1, String path2) { int result = 0; int end1 = path1.length(); int end2 = path2.length(); while (end1 > 0 && end2 > 0) { int slash1 = path1.lastIndexOf('/', end1 - 1); int slash2 = path2.lastIndexOf('/', end2 - 1); int backSlash1 = path1.lastIndexOf('\\', end1 - 1); int backSlash2 = path2.lastIndexOf('\\', end2 - 1); int start1 = (slash1 > backSlash1 ? slash1 : backSlash1); int start2 = (slash2 > backSlash2 ? slash2 : backSlash2); if (start1 < 0) start1 = 0; else start1++; if (start2 < 0) start2 = 0; else start2++; int length = end1 - start1; if (end2 - start2 != length) break; if (path1.regionMatches(true, start1, path2, start2, length)) { result++; end1 = start1 - 1; end2 = start2 - 1; } else break; } return result; } private boolean matchEntries(long rowId, String data) { int len = mPlaylistEntries.size(); boolean done = true; for (int i = 0; i < len; i++) { PlaylistEntry entry = mPlaylistEntries.get(i); if (entry.bestmatchlevel == Integer.MAX_VALUE) { continue; // this entry has been matched already } done = false; if (data.equalsIgnoreCase(entry.path)) { entry.bestmatchid = rowId; entry.bestmatchlevel = Integer.MAX_VALUE; continue; // no need for path matching } int matchLength = matchPaths(data, entry.path); if (matchLength > entry.bestmatchlevel) { entry.bestmatchid = rowId; entry.bestmatchlevel = matchLength; } } return done; } private void cachePlaylistEntry(String line, String playListDirectory) { PlaylistEntry entry = new PlaylistEntry(); // watch for trailing whitespace int entryLength = line.length(); while (entryLength > 0 && Character.isWhitespace(line.charAt(entryLength - 1))) entryLength--; // path should be longer than 3 characters. // avoid index out of bounds errors below by returning here. if (entryLength < 3) return; if (entryLength < line.length()) line = line.substring(0, entryLength); // does entry appear to be an absolute path? // look for Unix or DOS absolute paths char ch1 = line.charAt(0); boolean fullPath = (ch1 == '/' || (Character.isLetter(ch1) && line.charAt(1) == ':' && line.charAt(2) == '\\')); // if we have a relative path, combine entry with playListDirectory if (!fullPath) line = playListDirectory + line; entry.path = line; //FIXME - should we look for "../" within the path? mPlaylistEntries.add(entry); } private void processCachedPlaylist(Cursor fileList, ContentValues values, Uri playlistUri) { fileList.moveToPosition(-1); while (fileList.moveToNext()) { long rowId = fileList.getLong(FILES_PRESCAN_ID_COLUMN_INDEX); String data = fileList.getString(FILES_PRESCAN_PATH_COLUMN_INDEX); if (matchEntries(rowId, data)) { break; } } int len = mPlaylistEntries.size(); int index = 0; for (int i = 0; i < len; i++) { PlaylistEntry entry = mPlaylistEntries.get(i); if (entry.bestmatchlevel > 0) { try { values.clear(); values.put(MediaStore.Audio.Playlists.Members.PLAY_ORDER, Integer.valueOf(index)); values.put(MediaStore.Audio.Playlists.Members.AUDIO_ID, Long.valueOf(entry.bestmatchid)); mMediaProvider.insert(playlistUri, values); index++; } catch (RemoteException e) { Log.e(TAG, "RemoteException in MediaScanner.processCachedPlaylist()", e); return; } } } mPlaylistEntries.clear(); } private void processM3uPlayList(String path, String playListDirectory, Uri uri, ContentValues values, Cursor fileList) { BufferedReader reader = null; try { File f = new File(path); if (f.exists()) { reader = new BufferedReader( new InputStreamReader(new FileInputStream(f)), 8192); String line = reader.readLine(); mPlaylistEntries.clear(); while (line != null) { // ignore comment lines, which begin with '#' if (line.length() > 0 && line.charAt(0) != '#') { cachePlaylistEntry(line, playListDirectory); } line = reader.readLine(); } processCachedPlaylist(fileList, values, uri); } } catch (IOException e) { Log.e(TAG, "IOException in MediaScanner.processM3uPlayList()", e); } finally { try { if (reader != null) reader.close(); } catch (IOException e) { Log.e(TAG, "IOException in MediaScanner.processM3uPlayList()", e); } } } private void processPlsPlayList(String path, String playListDirectory, Uri uri, ContentValues values, Cursor fileList) { BufferedReader reader = null; try { File f = new File(path); if (f.exists()) { reader = new BufferedReader( new InputStreamReader(new FileInputStream(f)), 8192); String line = reader.readLine(); mPlaylistEntries.clear(); while (line != null) { // ignore comment lines, which begin with '#' if (line.startsWith("File")) { int equals = line.indexOf('='); if (equals > 0) { cachePlaylistEntry(line.substring(equals + 1), playListDirectory); } } line = reader.readLine(); } processCachedPlaylist(fileList, values, uri); } } catch (IOException e) { Log.e(TAG, "IOException in MediaScanner.processPlsPlayList()", e); } finally { try { if (reader != null) reader.close(); } catch (IOException e) { Log.e(TAG, "IOException in MediaScanner.processPlsPlayList()", e); } } } class WplHandler implements ElementListener { final ContentHandler handler; String playListDirectory; public WplHandler(String playListDirectory, Uri uri, Cursor fileList) { this.playListDirectory = playListDirectory; RootElement root = new RootElement("smil"); Element body = root.getChild("body"); Element seq = body.getChild("seq"); Element media = seq.getChild("media"); media.setElementListener(this); this.handler = root.getContentHandler(); } @Override public void start(Attributes attributes) { String path = attributes.getValue("", "src"); if (path != null) { cachePlaylistEntry(path, playListDirectory); } } @Override public void end() { } ContentHandler getContentHandler() { return handler; } } private void processWplPlayList(String path, String playListDirectory, Uri uri, ContentValues values, Cursor fileList) { FileInputStream fis = null; try { File f = new File(path); if (f.exists()) { fis = new FileInputStream(f); mPlaylistEntries.clear(); Xml.parse(fis, Xml.findEncodingByName("UTF-8"), new WplHandler(playListDirectory, uri, fileList).getContentHandler()); processCachedPlaylist(fileList, values, uri); } } catch (SAXException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { try { if (fis != null) fis.close(); } catch (IOException e) { Log.e(TAG, "IOException in MediaScanner.processWplPlayList()", e); } } } private void processPlayList(FileEntry entry, Cursor fileList) throws RemoteException { String path = entry.mPath; ContentValues values = new ContentValues(); int lastSlash = path.lastIndexOf('/'); if (lastSlash < 0) throw new IllegalArgumentException("bad path " + path); Uri uri, membersUri; long rowId = entry.mRowId; // make sure we have a name String name = values.getAsString(MediaStore.Audio.Playlists.NAME); if (name == null) { name = values.getAsString(MediaStore.MediaColumns.TITLE); if (name == null) { // extract name from file name int lastDot = path.lastIndexOf('.'); name = (lastDot < 0 ? path.substring(lastSlash + 1) : path.substring(lastSlash + 1, lastDot)); } } values.put(MediaStore.Audio.Playlists.NAME, name); values.put(MediaStore.Audio.Playlists.DATE_MODIFIED, entry.mLastModified); if (rowId == 0) { values.put(MediaStore.Audio.Playlists.DATA, path); uri = mMediaProvider.insert(mPlaylistsUri, values); rowId = ContentUris.parseId(uri); membersUri = Uri.withAppendedPath(uri, Playlists.Members.CONTENT_DIRECTORY); } else { uri = ContentUris.withAppendedId(mPlaylistsUri, rowId); mMediaProvider.update(uri, values, null, null); // delete members of existing playlist membersUri = Uri.withAppendedPath(uri, Playlists.Members.CONTENT_DIRECTORY); mMediaProvider.delete(membersUri, null, null); } String playListDirectory = path.substring(0, lastSlash + 1); MediaFile.MediaFileType mediaFileType = MediaFile.getFileType(path); int fileType = (mediaFileType == null ? 0 : mediaFileType.fileType); if (fileType == MediaFile.FILE_TYPE_M3U) { processM3uPlayList(path, playListDirectory, membersUri, values, fileList); } else if (fileType == MediaFile.FILE_TYPE_PLS) { processPlsPlayList(path, playListDirectory, membersUri, values, fileList); } else if (fileType == MediaFile.FILE_TYPE_WPL) { processWplPlayList(path, playListDirectory, membersUri, values, fileList); } } private void processPlayLists() throws RemoteException { Iterator<FileEntry> iterator = mPlayLists.iterator(); Cursor fileList = null; try { // use the files uri and projection because we need the format column, // but restrict the query to just audio files fileList = mMediaProvider.query(mFilesUri, FILES_PRESCAN_PROJECTION, "media_type=2", null, null, null); while (iterator.hasNext()) { FileEntry entry = iterator.next(); // only process playlist files if they are new or have been modified since the last scan if (entry.mLastModifiedChanged) { processPlayList(entry, fileList); } } } catch (RemoteException e1) { } finally { if (fileList != null) { fileList.close(); } } } private native void processDirectory(String path, MediaScannerClient client); private native void processFile(String path, String mimeType, MediaScannerClient client); public native void setLocale(String locale); public native byte[] extractAlbumArt(FileDescriptor fd); private static native final void native_init(); private native final void native_setup(); private native final void native_finalize(); /** * Releases resources associated with this MediaScanner object. * It is considered good practice to call this method when * one is done using the MediaScanner object. After this method * is called, the MediaScanner object can no longer be used. */ public void release() { native_finalize(); } @Override protected void finalize() { mContext.getContentResolver().releaseProvider(mMediaProvider); native_finalize(); }}假如 jni 想调用 java中函数 public void handleStringTag(String name, String value)
首先 jclass mediaScannerClientInterface =
env->FindClass(kClassMediaScannerClient);
获取 MediaScannerClient的本地类mediaScannerClientInterface
mHandleStringTagMethodID = env->GetMethodID(
mediaScannerClientInterface,
"handleStringTag",
"(Ljava/lang/String;Ljava/lang/String;)V");
获取mHandleStringTagMethodID获取MediaScannerClient的handleStringTag 在jni中的jmethodID，在调用 mEnv->CallVoidMethod(
mClient, mHandleStringTagMethodID, nameStr, valueStr);
CallVoidMethod 是jni调用java函数使用的函数。根据不同的返回类型使用不同的 call method函数（
返回值为void ： CallVoidMethod( ) A / V (无)
返回值为引用类型： CallObjectMethod( ) jobect
返回值为boolean ： CallBooleanMethod ( ) jboolean
返回值为byte ： CallByteMethod( ) jbyte
返回值为char ： CallCharMethod( ) jchar
返回值为short CallShortMethod( ) jshort
返回值为int ： CallIntMethod( ) jint
返回值为long： CallLongMethod() jlong
返回值为float ： CallFloatMethod() jfloat
返回值为double： CallDoubleMethod() jdouble
）本例中 handleStringTag 返回值为 void 所以使用 CallVoidMethod
allVoidMethod(
mClient, mHandleStringTagMethodID, nameStr, valueStr);
函数中第一个参数代表在MediaScannerClient的jobject对象。因为handleStringTag是MediaScannerClient的成员函数。所以jobject不能为 mediasanner
下一节我们给出实例！！！
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