从APK扩展文件中读取内容(来自obb文件)

Question

我已经实施了APK扩展文件下载服务,全部来自http://developer.android.com/google/play/expansion-files.html

我可以下载APK扩展文件,我可以使用下面的代码看到该文件

try {
        ZipResourceFile expansionFile = APKExpansionSupport
                .getAPKExpansionZipFile(this, 3, 0);

        ZipEntryRO[] zip = expansionFile.getAllEntries();
        Log.e("", "" + zip[0].mFile.getAbsolutePath());
        Log.e("", "" + zip[0].mFileName);
        Log.e("", "" + zip[0].mZipFileName);
        Log.e("", "" + zip[0].mCompressedLength);

        AssetFileDescriptor fd = expansionFile
                .getAssetFileDescriptor(zip[0].mFileName);

        if (fd != null && fd.getFileDescriptor() != null) {
            MediaPlayer mp = new MediaPlayer();
            mp.setDataSource(fd.getFileDescriptor());
            mp.start();
        } else {
            Log.e("", "fd or fd.getFileDescriptor() is null");
        }

    } catch (IOException e) {
        e.printStackTrace();
    }

我的obb有文件test.mp4和我的代码Log.e("", "" + zip[0].mFileName);打印test.mp4.

我的fd是null.为什么null？我试图解决但未能解决.

我只是无法读取obb文件中的任何文件..

未答复访问obb扩展文件中的文件提示想法,但它对我不起作用.

创建APK扩展文件的步骤告诉从obb解压缩内容然后读取它.它可靠而且好吗？

帮我!!需要最佳实践的意见.谢谢

编辑:

我的日志

03-01 10:36:40.848: E/(27836): zip[0].isUncompressed() : false
03-01 10:36:40.848: E/(27836): mFile.getAbsolutePath() : /storage/sdcard0/Android/obb/smart.trigger/main.3.smart.trigger.obb
03-01 10:36:40.848: E/(27836): mFileName : test.mp4
03-01 10:36:40.848: E/(27836): mZipFileName : /storage/sdcard0/Android/obb/smart.trigger/main.3.smart.trigger.obb
03-01 10:36:40.848: E/(27836): mCompressedLength : 21657598

Answer 1

我用Google搜索,发现我们shold不得不作出的.zip用0% (No compression)即提http://developer.android.com/google/play/expansion-files.html

Tip: If you're packaging media files into a ZIP, you can use media playback calls on the files with offset and length controls (such as MediaPlayer.setDataSource() and SoundPool.load()) without the need to unpack your ZIP. In order for this to work, you must not perform additional compression on the media files when creating the ZIP packages. For example, when using the zip tool, you should use the -n option to specify the file suffixes that should not be compressed: zip -n .mp4;.ogg main_expansion media_files

或者如何使用winrar制作0%压缩zip？

这里看压缩方法

mac中0%压缩zip

Create zip without compression on OS X from Terminal:
zip -r0 zipfilename.zip files-to-zip

所以我们应该在Play商店上传这个zip.

所以你不需要使用ZipHelper.java

只是简单地使用

ZipResourceFile expansionFile=null;

            try {
                expansionFile = APKExpansionSupport.getAPKExpansionZipFile(getApplicationContext(),3,0);

                     AssetFileDescriptor fd = expansionFile.getAssetFileDescriptor("test.mp4");
                     MediaPlayer mPlayer = new MediaPlayer();
                     mPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
                     mPlayer.setDataSource(fd.getFileDescriptor(),fd.getStartOffset(),fd.getLength());
                     mPlayer.prepare();
                     mPlayer.start();

            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

Answer 2

我已经使用解压缩解决了..

ZipHelper.java

public class ZipHelper {
static boolean zipError = false;

public static boolean isZipError() {
    return zipError;
}

public static void setZipError(boolean zipError) {
    ZipHelper.zipError = zipError;
}

public static void unzip(String archive, File outputDir) {
    try {
        Log.d("control", "ZipHelper.unzip() - File: " + archive);
        ZipFile zipfile = new ZipFile(archive);
        for (Enumeration<? extends ZipEntry> e = zipfile.entries(); e
                .hasMoreElements();) {
            ZipEntry entry = (ZipEntry) e.nextElement();
            unzipEntry(zipfile, entry, outputDir);

        }
    } catch (Exception e) {
        Log.d("control", "ZipHelper.unzip() - Error extracting file "
                + archive + ": " + e);
        setZipError(true);
    }
}

private static void unzipEntry(ZipFile zipfile, ZipEntry entry,
        File outputDir) throws IOException {
    if (entry.isDirectory()) {
        createDirectory(new File(outputDir, entry.getName()));
        return;
    }

    File outputFile = new File(outputDir, entry.getName());
    if (!outputFile.getParentFile().exists()) {
        createDirectory(outputFile.getParentFile());
    }

    Log.d("control", "ZipHelper.unzipEntry() - Extracting: " + entry);
    BufferedInputStream inputStream = new BufferedInputStream(
            zipfile.getInputStream(entry));
    BufferedOutputStream outputStream = new BufferedOutputStream(
            new FileOutputStream(outputFile));

    try {
        IOUtils.copy(inputStream, outputStream);
    } catch (Exception e) {
        Log.d("control", "ZipHelper.unzipEntry() - Error: " + e);
        setZipError(true);
    } finally {
        outputStream.close();
        inputStream.close();
    }
}

private static void createDirectory(File dir) {
    Log.d("control",
            "ZipHelper.createDir() - Creating directory: " + dir.getName());
    if (!dir.exists()) {
        if (!dir.mkdirs())
            throw new RuntimeException("Can't create directory " + dir);
    } else
        Log.d("control",
                "ZipHelper.createDir() - Exists directory: "
                        + dir.getName());
}
}

用法

try {
        ZipResourceFile expansionFile = APKExpansionSupport
                .getAPKExpansionZipFile(this, 3, 0);

        ZipEntryRO[] zip = expansionFile.getAllEntries();
        Log.e("", "zip[0].isUncompressed() : " + zip[0].isUncompressed());
        Log.e("",
                "mFile.getAbsolutePath() : "
                        + zip[0].mFile.getAbsolutePath());
        Log.e("", "mFileName : " + zip[0].mFileName);
        Log.e("", "mZipFileName : " + zip[0].mZipFileName);
        Log.e("", "mCompressedLength : " + zip[0].mCompressedLength);

        File file = new File(Environment.getExternalStorageDirectory()
                .getAbsolutePath() + "");
        ZipHelper.unzip(zip[0].mZipFileName, file);

        if (file.exists()) {
            Log.e("", "unzipped : " + file.getAbsolutePath());
        }

    } catch (Exception e) {
        e.printStackTrace();
    }