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MultiDexExtractor.javaAPI DocAndroid 5.1 API15733Thu Mar 12 22:22:48 GMT 2015android.support.multidex

MultiDexExtractor

public final class MultiDexExtractor extends Object
Exposes application secondary dex files as files in the application data directory.

Fields Summary
private static final String
TAG
private static final String
DEX_PREFIX
We look for additional dex files named {@code classes2.dex}, {@code classes3.dex}, etc.
private static final String
DEX_SUFFIX
private static final String
EXTRACTED_NAME_EXT
private static final String
EXTRACTED_SUFFIX
private static final int
MAX_EXTRACT_ATTEMPTS
private static final String
PREFS_FILE
private static final String
KEY_TIME_STAMP
private static final String
KEY_CRC
private static final String
KEY_DEX_NUMBER
private static final int
BUFFER_SIZE
Size of reading buffers.
private static final long
NO_VALUE
private static Method
sApplyMethod
Constructors Summary
Methods Summary
private static voidapply(SharedPreferences.Editor editor)

        try {
            Class<?> cls = SharedPreferences.Editor.class;
            sApplyMethod = cls.getMethod("apply");
        } catch (NoSuchMethodException unused) {
            sApplyMethod = null;
        }
    
        if (sApplyMethod != null) {
            try {
                sApplyMethod.invoke(editor);
                return;
            } catch (InvocationTargetException unused) {
                // fall through
            } catch (IllegalAccessException unused) {
                // fall through
            }
        }
        editor.commit();
private static voidcloseQuietly(java.io.Closeable closeable)
Closes the given {@code Closeable}. Suppresses any IO exceptions.

        try {
            closeable.close();
        } catch (IOException e) {
            Log.w(TAG, "Failed to close resource", e);
        }
private static voidextract(java.util.zip.ZipFile apk, java.util.zip.ZipEntry dexFile, java.io.File extractTo, java.lang.String extractedFilePrefix)


        InputStream in = apk.getInputStream(dexFile);
        ZipOutputStream out = null;
        File tmp = File.createTempFile(extractedFilePrefix, EXTRACTED_SUFFIX,
                extractTo.getParentFile());
        Log.i(TAG, "Extracting " + tmp.getPath());
        try {
            out = new ZipOutputStream(new BufferedOutputStream(new FileOutputStream(tmp)));
            try {
                ZipEntry classesDex = new ZipEntry("classes.dex");
                // keep zip entry time since it is the criteria used by Dalvik
                classesDex.setTime(dexFile.getTime());
                out.putNextEntry(classesDex);

                byte[] buffer = new byte[BUFFER_SIZE];
                int length = in.read(buffer);
                while (length != -1) {
                    out.write(buffer, 0, length);
                    length = in.read(buffer);
                }
                out.closeEntry();
            } finally {
                out.close();
            }
            Log.i(TAG, "Renaming to " + extractTo.getPath());
            if (!tmp.renameTo(extractTo)) {
                throw new IOException("Failed to rename \"" + tmp.getAbsolutePath() +
                        "\" to \"" + extractTo.getAbsolutePath() + "\"");
            }
        } finally {
            closeQuietly(in);
            tmp.delete(); // return status ignored
        }
private static android.content.SharedPreferencesgetMultiDexPreferences(android.content.Context context)

        return context.getSharedPreferences(PREFS_FILE,
                Build.VERSION.SDK_INT < 11 /* Build.VERSION_CODES.HONEYCOMB */
                        ? Context.MODE_PRIVATE
                        : Context.MODE_PRIVATE | 0x0004 /* Context.MODE_MULTI_PROCESS */);
private static longgetTimeStamp(java.io.File archive)

        long timeStamp = archive.lastModified();
        if (timeStamp == NO_VALUE) {
            // never return NO_VALUE
            timeStamp--;
        }
        return timeStamp;
private static longgetZipCrc(java.io.File archive)

        long computedValue = ZipUtil.getZipCrc(archive);
        if (computedValue == NO_VALUE) {
            // never return NO_VALUE
            computedValue--;
        }
        return computedValue;
private static booleanisModified(android.content.Context context, java.io.File archive, long currentCrc)

        SharedPreferences prefs = getMultiDexPreferences(context);
        return (prefs.getLong(KEY_TIME_STAMP, NO_VALUE) != getTimeStamp(archive))
                || (prefs.getLong(KEY_CRC, NO_VALUE) != currentCrc);
static java.util.Listload(android.content.Context context, android.content.pm.ApplicationInfo applicationInfo, java.io.File dexDir, boolean forceReload)
Extracts application secondary dexes into files in the application data directory.

return
a list of files that were created. The list may be empty if there are no secondary dex files.
throws
IOException if encounters a problem while reading or writing secondary dex files


                                                                     
           
                
        Log.i(TAG, "MultiDexExtractor.load(" + applicationInfo.sourceDir + ", " + forceReload + ")");
        final File sourceApk = new File(applicationInfo.sourceDir);

        long currentCrc = getZipCrc(sourceApk);

        List<File> files;
        if (!forceReload && !isModified(context, sourceApk, currentCrc)) {
            try {
                files = loadExistingExtractions(context, sourceApk, dexDir);
            } catch (IOException ioe) {
                Log.w(TAG, "Failed to reload existing extracted secondary dex files,"
                        + " falling back to fresh extraction", ioe);
                files = performExtractions(sourceApk, dexDir);
                putStoredApkInfo(context, getTimeStamp(sourceApk), currentCrc, files.size() + 1);

            }
        } else {
            Log.i(TAG, "Detected that extraction must be performed.");
            files = performExtractions(sourceApk, dexDir);
            putStoredApkInfo(context, getTimeStamp(sourceApk), currentCrc, files.size() + 1);
        }

        Log.i(TAG, "load found " + files.size() + " secondary dex files");
        return files;
private static java.util.ListloadExistingExtractions(android.content.Context context, java.io.File sourceApk, java.io.File dexDir)

        Log.i(TAG, "loading existing secondary dex files");

        final String extractedFilePrefix = sourceApk.getName() + EXTRACTED_NAME_EXT;
        int totalDexNumber = getMultiDexPreferences(context).getInt(KEY_DEX_NUMBER, 1);
        final List<File> files = new ArrayList<File>(totalDexNumber);

        for (int secondaryNumber = 2; secondaryNumber <= totalDexNumber; secondaryNumber++) {
            String fileName = extractedFilePrefix + secondaryNumber + EXTRACTED_SUFFIX;
            File extractedFile = new File(dexDir, fileName);
            if (extractedFile.isFile()) {
                files.add(extractedFile);
                if (!verifyZipFile(extractedFile)) {
                    Log.i(TAG, "Invalid zip file: " + extractedFile);
                    throw new IOException("Invalid ZIP file.");
                }
            } else {
                throw new IOException("Missing extracted secondary dex file '" +
                        extractedFile.getPath() + "'");
            }
        }

        return files;
private static voidmkdirChecked(java.io.File dir)

        dir.mkdir();
        if (!dir.isDirectory()) {
            File parent = dir.getParentFile();
            if (parent == null) {
                Log.e(TAG, "Failed to create dir " + dir.getPath() + ". Parent file is null.");
            } else {
                Log.e(TAG, "Failed to create dir " + dir.getPath() +
                        ". parent file is a dir " + parent.isDirectory() +
                        ", a file " + parent.isFile() +
                        ", exists " + parent.exists() +
                        ", readable " + parent.canRead() +
                        ", writable " + parent.canWrite());
            }
            throw new IOException("Failed to create cache directory " + dir.getPath());
        }
private static java.util.ListperformExtractions(java.io.File sourceApk, java.io.File dexDir)


        final String extractedFilePrefix = sourceApk.getName() + EXTRACTED_NAME_EXT;

        // Ensure that whatever deletions happen in prepareDexDir only happen if the zip that
        // contains a secondary dex file in there is not consistent with the latest apk.  Otherwise,
        // multi-process race conditions can cause a crash loop where one process deletes the zip
        // while another had created it.
        prepareDexDir(dexDir, extractedFilePrefix);

        List<File> files = new ArrayList<File>();

        final ZipFile apk = new ZipFile(sourceApk);
        try {

            int secondaryNumber = 2;

            ZipEntry dexFile = apk.getEntry(DEX_PREFIX + secondaryNumber + DEX_SUFFIX);
            while (dexFile != null) {
                String fileName = extractedFilePrefix + secondaryNumber + EXTRACTED_SUFFIX;
                File extractedFile = new File(dexDir, fileName);
                files.add(extractedFile);

                Log.i(TAG, "Extraction is needed for file " + extractedFile);
                int numAttempts = 0;
                boolean isExtractionSuccessful = false;
                while (numAttempts < MAX_EXTRACT_ATTEMPTS && !isExtractionSuccessful) {
                    numAttempts++;

                    // Create a zip file (extractedFile) containing only the secondary dex file
                    // (dexFile) from the apk.
                    extract(apk, dexFile, extractedFile, extractedFilePrefix);

                    // Verify that the extracted file is indeed a zip file.
                    isExtractionSuccessful = verifyZipFile(extractedFile);

                    // Log the sha1 of the extracted zip file
                    Log.i(TAG, "Extraction " + (isExtractionSuccessful ? "success" : "failed") +
                            " - length " + extractedFile.getAbsolutePath() + ": " +
                            extractedFile.length());
                    if (!isExtractionSuccessful) {
                        // Delete the extracted file
                        extractedFile.delete();
                        if (extractedFile.exists()) {
                            Log.w(TAG, "Failed to delete corrupted secondary dex '" +
                                    extractedFile.getPath() + "'");
                        }
                    }
                }
                if (!isExtractionSuccessful) {
                    throw new IOException("Could not create zip file " +
                            extractedFile.getAbsolutePath() + " for secondary dex (" +
                            secondaryNumber + ")");
                }
                secondaryNumber++;
                dexFile = apk.getEntry(DEX_PREFIX + secondaryNumber + DEX_SUFFIX);
            }
        } finally {
            try {
                apk.close();
            } catch (IOException e) {
                Log.w(TAG, "Failed to close resource", e);
            }
        }

        return files;
private static voidprepareDexDir(java.io.File dexDir, java.lang.String extractedFilePrefix)
This removes any files that do not have the correct prefix.

        /* mkdirs() has some bugs, especially before jb-mr1 and we have only a maximum of one parent
         * to create, lets stick to mkdir().
         */
        File cache = dexDir.getParentFile();
        mkdirChecked(cache);
        mkdirChecked(dexDir);

        // Clean possible old files
        FileFilter filter = new FileFilter() {

            @Override
            public boolean accept(File pathname) {
                return !pathname.getName().startsWith(extractedFilePrefix);
            }
        };
        File[] files = dexDir.listFiles(filter);
        if (files == null) {
            Log.w(TAG, "Failed to list secondary dex dir content (" + dexDir.getPath() + ").");
            return;
        }
        for (File oldFile : files) {
            Log.i(TAG, "Trying to delete old file " + oldFile.getPath() + " of size " +
                    oldFile.length());
            if (!oldFile.delete()) {
                Log.w(TAG, "Failed to delete old file " + oldFile.getPath());
            } else {
                Log.i(TAG, "Deleted old file " + oldFile.getPath());
            }
        }
private static voidputStoredApkInfo(android.content.Context context, long timeStamp, long crc, int totalDexNumber)

        SharedPreferences prefs = getMultiDexPreferences(context);
        SharedPreferences.Editor edit = prefs.edit();
        edit.putLong(KEY_TIME_STAMP, timeStamp);
        edit.putLong(KEY_CRC, crc);
        /* SharedPreferences.Editor doc says that apply() and commit() "atomically performs the
         * requested modifications" it should be OK to rely on saving the dex files number (getting
         * old number value would go along with old crc and time stamp).
         */
        edit.putInt(KEY_DEX_NUMBER, totalDexNumber);
        apply(edit);
static booleanverifyZipFile(java.io.File file)
Returns whether the file is a valid zip file.

        try {
            ZipFile zipFile = new ZipFile(file);
            try {
                zipFile.close();
                return true;
            } catch (IOException e) {
                Log.w(TAG, "Failed to close zip file: " + file.getAbsolutePath());
            }
        } catch (ZipException ex) {
            Log.w(TAG, "File " + file.getAbsolutePath() + " is not a valid zip file.", ex);
        } catch (IOException ex) {
            Log.w(TAG, "Got an IOException trying to open zip file: " + file.getAbsolutePath(), ex);
        }
        return false;