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Diffstat (limited to 'drm/java/android/drm/DrmUtils.java')
| -rw-r--r-- | drm/java/android/drm/DrmUtils.java | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/drm/java/android/drm/DrmUtils.java b/drm/java/android/drm/DrmUtils.java new file mode 100644 index 000000000000..5e5397c45874 --- /dev/null +++ b/drm/java/android/drm/DrmUtils.java @@ -0,0 +1,188 @@ +/* + * Copyright (C) 2010 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.drm; + +import java.io.BufferedInputStream; +import java.io.File; +import java.io.FileInputStream; +import java.io.FileNotFoundException; +import java.io.FileOutputStream; +import java.io.IOException; +import java.io.InputStream; +import java.io.OutputStream; +import java.util.HashMap; +import java.util.Iterator; + +/** + * The utility class used in the DRM Framework. This inclueds APIs for file operations + * and ExtendedMetadataParser for parsing extended metadata BLOB in DRM constraints. + * + */ +public class DrmUtils { + /* Should be used when we need to read from local file */ + /* package */ static byte[] readBytes(String path) throws IOException { + File file = new File(path); + return readBytes(file); + } + + /* Should be used when we need to read from local file */ + /* package */ static byte[] readBytes(File file) throws IOException { + FileInputStream inputStream = new FileInputStream(file); + BufferedInputStream bufferedStream = new BufferedInputStream(inputStream); + byte[] data = null; + + try { + int length = bufferedStream.available(); + if (length > 0) { + data = new byte[length]; + // read the entire data + bufferedStream.read(data); + } + } finally { + quiteDispose(bufferedStream); + quiteDispose(inputStream); + } + return data; + } + + /* package */ static void writeToFile(final String path, byte[] data) throws IOException { + /* check for invalid inputs */ + FileOutputStream outputStream = null; + + if (null != path && null != data) { + try { + outputStream = new FileOutputStream(path); + outputStream.write(data); + } finally { + quiteDispose(outputStream); + } + } + } + + /* package */ static void removeFile(String path) throws IOException { + File file = new File(path); + file.delete(); + } + + private static void quiteDispose(InputStream stream) { + try { + if (null != stream) { + stream.close(); + } + } catch (IOException e) { + // no need to care, at least as of now + } + } + + private static void quiteDispose(OutputStream stream) { + try { + if (null != stream) { + stream.close(); + } + } catch (IOException e) { + // no need to care + } + } + + /** + * Get an instance of ExtendedMetadataParser to be used for parsing + * extended metadata BLOB in DRM constraints. <br> + * + * extendedMetadata BLOB is retrieved by specifing + * key DrmStore.ConstraintsColumns.EXTENDED_METADATA. + * + * @param extendedMetadata BLOB in which key-value pairs of extended metadata are embedded. + * + */ + public static ExtendedMetadataParser getExtendedMetadataParser(byte[] extendedMetadata) { + return new ExtendedMetadataParser(extendedMetadata); + } + + /** + * Utility parser to parse the extended meta-data embedded inside DRM constraints<br><br> + * + * Usage example<br> + * byte[] extendedMetadata<br> + * = + * constraints.getAsByteArray(DrmStore.ConstraintsColumns.EXTENDED_METADATA);<br> + * ExtendedMetadataParser parser = getExtendedMetadataParser(extendedMetadata);<br> + * Iterator keyIterator = parser.keyIterator();<br> + * while (keyIterator.hasNext()) {<br> + * String extendedMetadataKey = keyIterator.next();<br> + * String extendedMetadataValue = + * parser.get(extendedMetadataKey);<br> + * } + */ + public static class ExtendedMetadataParser { + HashMap<String, String> mMap = new HashMap<String, String>(); + + private int readByte(byte[] constraintData, int arrayIndex) { + //Convert byte[] into int. + return (int)constraintData[arrayIndex]; + } + + private String readMultipleBytes( + byte[] constraintData, int numberOfBytes, int arrayIndex) { + byte[] returnBytes = new byte[numberOfBytes]; + for (int j = arrayIndex, i = 0; j < arrayIndex + numberOfBytes; j++,i++) { + returnBytes[i] = constraintData[j]; + } + return new String(returnBytes); + } + + /* + * This will parse the following format + * KeyLengthValueLengthKeyValueKeyLength1ValueLength1Key1Value1..\0 + */ + private ExtendedMetadataParser(byte[] constraintData) { + //Extract KeyValue Pair Info, till terminator occurs. + int index = 0; + + while (index < constraintData.length) { + //Parse Key Length + int keyLength = readByte(constraintData, index); + index++; + + //Parse Value Length + int valueLength = readByte(constraintData, index); + index++; + + //Fetch key + String strKey = readMultipleBytes(constraintData, keyLength, index); + index += keyLength; + + //Fetch Value + String strValue = readMultipleBytes(constraintData, valueLength, index); + index += valueLength; + mMap.put(strKey, strValue); + } + } + + public Iterator<String> iterator() { + return mMap.values().iterator(); + } + + public Iterator<String> keyIterator() { + return mMap.keySet().iterator(); + } + + public String get(String key) { + return mMap.get(key); + } + } +} + |