--- /dev/null
+/*
+ * 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 be.nikiroo.utils.streams;
+
+import java.io.FilterOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+
+/**
+ * An OutputStream that does Base64 encoding on the data written to
+ * it, writing the resulting data to another OutputStream.
+ */
+public class Base64OutputStream extends FilterOutputStream {
+ private final Base64.Coder coder;
+ private final int flags;
+
+ private byte[] buffer = null;
+ private int bpos = 0;
+
+ private static byte[] EMPTY = new byte[0];
+
+ /**
+ * Performs Base64 encoding on the data written to the stream,
+ * writing the encoded data to another OutputStream.
+ *
+ * @param out the OutputStream to write the encoded data to
+ */
+ public Base64OutputStream(OutputStream out) {
+ this(out, true);
+ }
+
+ /**
+ * Performs Base64 encoding or decoding on the data written to the
+ * stream, writing the encoded/decoded data to another
+ * OutputStream.
+ *
+ * @param out the OutputStream to write the encoded data to
+ * @param encode true to encode, false to decode
+ *
+ * @hide
+ */
+ public Base64OutputStream(OutputStream out, boolean encode) {
+ super(out);
+ this.flags = Base64.NO_WRAP;
+ if (encode) {
+ coder = new Base64.Encoder(flags, null);
+ } else {
+ coder = new Base64.Decoder(flags, null);
+ }
+ }
+
+ @Override
+ public void write(int b) throws IOException {
+ // To avoid invoking the encoder/decoder routines for single
+ // bytes, we buffer up calls to write(int) in an internal
+ // byte array to transform them into writes of decently-sized
+ // arrays.
+
+ if (buffer == null) {
+ buffer = new byte[1024];
+ }
+ if (bpos >= buffer.length) {
+ // internal buffer full; write it out.
+ internalWrite(buffer, 0, bpos, false);
+ bpos = 0;
+ }
+ buffer[bpos++] = (byte) b;
+ }
+
+ /**
+ * Flush any buffered data from calls to write(int). Needed
+ * before doing a write(byte[], int, int) or a close().
+ */
+ private void flushBuffer() throws IOException {
+ if (bpos > 0) {
+ internalWrite(buffer, 0, bpos, false);
+ bpos = 0;
+ }
+ }
+
+ @Override
+ public void write(byte[] b, int off, int len) throws IOException {
+ if (len <= 0) return;
+ flushBuffer();
+ internalWrite(b, off, len, false);
+ }
+
+ @Override
+ public void close() throws IOException {
+ IOException thrown = null;
+ try {
+ flushBuffer();
+ internalWrite(EMPTY, 0, 0, true);
+ } catch (IOException e) {
+ thrown = e;
+ }
+
+ try {
+ if ((flags & Base64.NO_CLOSE) == 0) {
+ out.close();
+ } else {
+ out.flush();
+ }
+ } catch (IOException e) {
+ if (thrown != null) {
+ thrown = e;
+ }
+ }
+
+ if (thrown != null) {
+ throw thrown;
+ }
+ }
+
+ /**
+ * Write the given bytes to the encoder/decoder.
+ *
+ * @param finish true if this is the last batch of input, to cause
+ * encoder/decoder state to be finalized.
+ */
+ private void internalWrite(byte[] b, int off, int len, boolean finish) throws IOException {
+ coder.output = embiggen(coder.output, coder.maxOutputSize(len));
+ if (!coder.process(b, off, len, finish)) {
+ throw new IOException("bad base-64");
+ }
+ out.write(coder.output, 0, coder.op);
+ }
+
+ /**
+ * If b.length is at least len, return b. Otherwise return a new
+ * byte array of length len.
+ */
+ private byte[] embiggen(byte[] b, int len) {
+ if (b == null || b.length < len) {
+ return new byte[len];
+ }
+ return b;
+ }
+}