| /** |
| * Copyright (C) 2012 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| * use this file except in compliance with the License. You may obtain a copy of |
| * the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| * License for the specific language governing permissions and limitations under |
| * the License. |
| */ |
| |
| package com.android.inputmethod.dictionarypack; |
| |
| import java.io.InputStream; |
| import java.io.IOException; |
| import java.security.MessageDigest; |
| |
| final class MD5Calculator { |
| private MD5Calculator() {} // This helper class is not instantiable |
| |
| public static String checksum(final InputStream in) throws IOException { |
| // This code from the Android documentation for MessageDigest. Nearly verbatim. |
| MessageDigest digester; |
| try { |
| digester = MessageDigest.getInstance("MD5"); |
| } catch (java.security.NoSuchAlgorithmException e) { |
| return null; // Platform does not support MD5 : can't check, so return null |
| } |
| final byte[] bytes = new byte[8192]; |
| int byteCount; |
| while ((byteCount = in.read(bytes)) > 0) { |
| digester.update(bytes, 0, byteCount); |
| } |
| final byte[] digest = digester.digest(); |
| final StringBuilder s = new StringBuilder(); |
| for (int i = 0; i < digest.length; ++i) { |
| s.append(String.format("%1$02x", digest[i])); |
| } |
| return s.toString(); |
| } |
| } |