| /* |
| * 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.util; |
| |
| import java.io.FilterInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| /** |
| * An InputStream that does Base64 decoding on the data read through |
| * it. |
| */ |
| public class Base64InputStream extends FilterInputStream { |
| private final Base64.Coder coder; |
| |
| private static byte[] EMPTY = new byte[0]; |
| |
| private static final int BUFFER_SIZE = 2048; |
| private boolean eof; |
| private byte[] inputBuffer; |
| private int outputStart; |
| private int outputEnd; |
| |
| /** |
| * An InputStream that performs Base64 decoding on the data read |
| * from the wrapped stream. |
| * |
| * @param in the InputStream to read the source data from |
| * @param flags bit flags for controlling the decoder; see the |
| * constants in {@link Base64} |
| */ |
| public Base64InputStream(InputStream in, int flags) { |
| this(in, flags, false); |
| } |
| |
| /** |
| * Performs Base64 encoding or decoding on the data read from the |
| * wrapped InputStream. |
| * |
| * @param in the InputStream to read the source data from |
| * @param flags bit flags for controlling the decoder; see the |
| * constants in {@link Base64} |
| * @param encode true to encode, false to decode |
| * |
| * @hide |
| */ |
| public Base64InputStream(InputStream in, int flags, boolean encode) { |
| super(in); |
| eof = false; |
| inputBuffer = new byte[BUFFER_SIZE]; |
| if (encode) { |
| coder = new Base64.Encoder(flags, null); |
| } else { |
| coder = new Base64.Decoder(flags, null); |
| } |
| coder.output = new byte[coder.maxOutputSize(BUFFER_SIZE)]; |
| outputStart = 0; |
| outputEnd = 0; |
| } |
| |
| public boolean markSupported() { |
| return false; |
| } |
| |
| public void mark(int readlimit) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| public void reset() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| public void close() throws IOException { |
| in.close(); |
| inputBuffer = null; |
| } |
| |
| public int available() { |
| return outputEnd - outputStart; |
| } |
| |
| public long skip(long n) throws IOException { |
| if (outputStart >= outputEnd) { |
| refill(); |
| } |
| if (outputStart >= outputEnd) { |
| return 0; |
| } |
| long bytes = Math.min(n, outputEnd-outputStart); |
| outputStart += bytes; |
| return bytes; |
| } |
| |
| public int read() throws IOException { |
| if (outputStart >= outputEnd) { |
| refill(); |
| } |
| if (outputStart >= outputEnd) { |
| return -1; |
| } else { |
| return coder.output[outputStart++] & 0xff; |
| } |
| } |
| |
| public int read(byte[] b, int off, int len) throws IOException { |
| if (outputStart >= outputEnd) { |
| refill(); |
| } |
| if (outputStart >= outputEnd) { |
| return -1; |
| } |
| int bytes = Math.min(len, outputEnd-outputStart); |
| System.arraycopy(coder.output, outputStart, b, off, bytes); |
| outputStart += bytes; |
| return bytes; |
| } |
| |
| /** |
| * Read data from the input stream into inputBuffer, then |
| * decode/encode it into the empty coder.output, and reset the |
| * outputStart and outputEnd pointers. |
| */ |
| private void refill() throws IOException { |
| if (eof) return; |
| int bytesRead = in.read(inputBuffer); |
| boolean success; |
| if (bytesRead == -1) { |
| eof = true; |
| success = coder.process(EMPTY, 0, 0, true); |
| } else { |
| success = coder.process(inputBuffer, 0, bytesRead, false); |
| } |
| if (!success) { |
| throw new Base64DataException("bad base-64"); |
| } |
| outputEnd = coder.op; |
| outputStart = 0; |
| } |
| } |