Doug Zongker | d2affae | 2010-02-12 15:50:01 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2010 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
Doug Zongker | ab69e29 | 2010-03-29 13:23:15 -0700 | [diff] [blame] | 17 | package android.util; |
Doug Zongker | d2affae | 2010-02-12 15:50:01 -0800 | [diff] [blame] | 18 | |
| 19 | import java.io.FilterOutputStream; |
| 20 | import java.io.IOException; |
| 21 | import java.io.OutputStream; |
| 22 | |
| 23 | /** |
Doug Zongker | 33f7a80 | 2010-02-12 17:41:40 -0800 | [diff] [blame] | 24 | * An OutputStream that does Base64 encoding on the data written to |
| 25 | * it, writing the resulting data to another OutputStream. |
Doug Zongker | d2affae | 2010-02-12 15:50:01 -0800 | [diff] [blame] | 26 | */ |
| 27 | public class Base64OutputStream extends FilterOutputStream { |
Doug Zongker | 9df2ffd | 2010-02-14 13:48:49 -0800 | [diff] [blame] | 28 | private final Base64.Coder coder; |
Doug Zongker | d2affae | 2010-02-12 15:50:01 -0800 | [diff] [blame] | 29 | private final int flags; |
| 30 | |
| 31 | private byte[] buffer = null; |
| 32 | private int bpos = 0; |
| 33 | |
| 34 | private static byte[] EMPTY = new byte[0]; |
| 35 | |
| 36 | /** |
| 37 | * Performs Base64 encoding on the data written to the stream, |
| 38 | * writing the encoded data to another OutputStream. |
| 39 | * |
| 40 | * @param out the OutputStream to write the encoded data to |
| 41 | * @param flags bit flags for controlling the encoder; see the |
| 42 | * constants in {@link Base64} |
| 43 | */ |
| 44 | public Base64OutputStream(OutputStream out, int flags) { |
| 45 | this(out, flags, true); |
| 46 | } |
| 47 | |
| 48 | /** |
| 49 | * Performs Base64 encoding or decoding on the data written to the |
| 50 | * stream, writing the encoded/decoded data to another |
| 51 | * OutputStream. |
| 52 | * |
| 53 | * @param out the OutputStream to write the encoded data to |
| 54 | * @param flags bit flags for controlling the encoder; see the |
| 55 | * constants in {@link Base64} |
| 56 | * @param encode true to encode, false to decode |
Doug Zongker | 33f7a80 | 2010-02-12 17:41:40 -0800 | [diff] [blame] | 57 | * |
| 58 | * @hide |
Doug Zongker | d2affae | 2010-02-12 15:50:01 -0800 | [diff] [blame] | 59 | */ |
| 60 | public Base64OutputStream(OutputStream out, int flags, boolean encode) { |
| 61 | super(out); |
| 62 | this.flags = flags; |
Doug Zongker | d2affae | 2010-02-12 15:50:01 -0800 | [diff] [blame] | 63 | if (encode) { |
Doug Zongker | 9df2ffd | 2010-02-14 13:48:49 -0800 | [diff] [blame] | 64 | coder = new Base64.Encoder(flags, null); |
Doug Zongker | d2affae | 2010-02-12 15:50:01 -0800 | [diff] [blame] | 65 | } else { |
Doug Zongker | 9df2ffd | 2010-02-14 13:48:49 -0800 | [diff] [blame] | 66 | coder = new Base64.Decoder(flags, null); |
Doug Zongker | d2affae | 2010-02-12 15:50:01 -0800 | [diff] [blame] | 67 | } |
| 68 | } |
| 69 | |
| 70 | public void write(int b) throws IOException { |
| 71 | // To avoid invoking the encoder/decoder routines for single |
| 72 | // bytes, we buffer up calls to write(int) in an internal |
| 73 | // byte array to transform them into writes of decently-sized |
| 74 | // arrays. |
| 75 | |
| 76 | if (buffer == null) { |
| 77 | buffer = new byte[1024]; |
| 78 | } |
| 79 | if (bpos >= buffer.length) { |
| 80 | // internal buffer full; write it out. |
| 81 | internalWrite(buffer, 0, bpos, false); |
| 82 | bpos = 0; |
| 83 | } |
| 84 | buffer[bpos++] = (byte) b; |
| 85 | } |
| 86 | |
| 87 | /** |
| 88 | * Flush any buffered data from calls to write(int). Needed |
| 89 | * before doing a write(byte[], int, int) or a close(). |
| 90 | */ |
| 91 | private void flushBuffer() throws IOException { |
| 92 | if (bpos > 0) { |
| 93 | internalWrite(buffer, 0, bpos, false); |
| 94 | bpos = 0; |
| 95 | } |
| 96 | } |
| 97 | |
| 98 | public void write(byte[] b, int off, int len) throws IOException { |
| 99 | if (len <= 0) return; |
| 100 | flushBuffer(); |
| 101 | internalWrite(b, off, len, false); |
| 102 | } |
| 103 | |
| 104 | public void close() throws IOException { |
Doug Zongker | 9df2ffd | 2010-02-14 13:48:49 -0800 | [diff] [blame] | 105 | IOException thrown = null; |
| 106 | try { |
| 107 | flushBuffer(); |
| 108 | internalWrite(EMPTY, 0, 0, true); |
| 109 | } catch (IOException e) { |
| 110 | thrown = e; |
| 111 | } |
| 112 | |
| 113 | try { |
| 114 | if ((flags & Base64.NO_CLOSE) == 0) { |
| 115 | out.close(); |
| 116 | } else { |
| 117 | out.flush(); |
| 118 | } |
| 119 | } catch (IOException e) { |
Tobias Thierer | 97c4d13 | 2018-07-23 12:53:00 +0100 | [diff] [blame] | 120 | if (thrown == null) { |
Doug Zongker | 9df2ffd | 2010-02-14 13:48:49 -0800 | [diff] [blame] | 121 | thrown = e; |
Tobias Thierer | 97c4d13 | 2018-07-23 12:53:00 +0100 | [diff] [blame] | 122 | } else { |
| 123 | thrown.addSuppressed(e); |
Doug Zongker | 9df2ffd | 2010-02-14 13:48:49 -0800 | [diff] [blame] | 124 | } |
| 125 | } |
| 126 | |
| 127 | if (thrown != null) { |
| 128 | throw thrown; |
Doug Zongker | d2affae | 2010-02-12 15:50:01 -0800 | [diff] [blame] | 129 | } |
| 130 | } |
| 131 | |
| 132 | /** |
| 133 | * Write the given bytes to the encoder/decoder. |
| 134 | * |
| 135 | * @param finish true if this is the last batch of input, to cause |
| 136 | * encoder/decoder state to be finalized. |
| 137 | */ |
| 138 | private void internalWrite(byte[] b, int off, int len, boolean finish) throws IOException { |
Doug Zongker | 9df2ffd | 2010-02-14 13:48:49 -0800 | [diff] [blame] | 139 | coder.output = embiggen(coder.output, coder.maxOutputSize(len)); |
| 140 | if (!coder.process(b, off, len, finish)) { |
Andy Stadler | c5a0ce2 | 2011-01-24 16:47:56 -0800 | [diff] [blame] | 141 | throw new Base64DataException("bad base-64"); |
Doug Zongker | d2affae | 2010-02-12 15:50:01 -0800 | [diff] [blame] | 142 | } |
Doug Zongker | 9df2ffd | 2010-02-14 13:48:49 -0800 | [diff] [blame] | 143 | out.write(coder.output, 0, coder.op); |
Doug Zongker | d2affae | 2010-02-12 15:50:01 -0800 | [diff] [blame] | 144 | } |
| 145 | |
| 146 | /** |
| 147 | * If b.length is at least len, return b. Otherwise return a new |
| 148 | * byte array of length len. |
| 149 | */ |
| 150 | private byte[] embiggen(byte[] b, int len) { |
| 151 | if (b == null || b.length < len) { |
| 152 | return new byte[len]; |
| 153 | } else { |
| 154 | return b; |
| 155 | } |
| 156 | } |
| 157 | } |