| /* |
| * Copyright (C) 2007 Esmertec AG. |
| * 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 com.google.android.mms.pdu; |
| |
| import java.io.ByteArrayOutputStream; |
| |
| public class QuotedPrintable { |
| private static byte ESCAPE_CHAR = '='; |
| |
| /** |
| * Decodes an array quoted-printable characters into an array of original bytes. |
| * Escaped characters are converted back to their original representation. |
| * |
| * <p> |
| * This function implements a subset of |
| * quoted-printable encoding specification (rule #1 and rule #2) |
| * as defined in RFC 1521. |
| * </p> |
| * |
| * @param bytes array of quoted-printable characters |
| * @return array of original bytes, |
| * null if quoted-printable decoding is unsuccessful. |
| */ |
| public static final byte[] decodeQuotedPrintable(byte[] bytes) { |
| if (bytes == null) { |
| return null; |
| } |
| ByteArrayOutputStream buffer = new ByteArrayOutputStream(); |
| for (int i = 0; i < bytes.length; i++) { |
| int b = bytes[i]; |
| if (b == ESCAPE_CHAR) { |
| try { |
| if('\r' == (char)bytes[i + 1] && |
| '\n' == (char)bytes[i + 2]) { |
| i += 2; |
| continue; |
| } |
| int u = Character.digit((char) bytes[++i], 16); |
| int l = Character.digit((char) bytes[++i], 16); |
| if (u == -1 || l == -1) { |
| return null; |
| } |
| buffer.write((char) ((u << 4) + l)); |
| } catch (ArrayIndexOutOfBoundsException e) { |
| return null; |
| } |
| } else { |
| buffer.write(b); |
| } |
| } |
| return buffer.toByteArray(); |
| } |
| } |