| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 java.io; |
| |
| import org.apache.harmony.luni.util.Msg; |
| |
| // BEGIN android-added |
| import java.util.logging.Logger; |
| // END android-added |
| |
| /** |
| * Wraps an existing {@link OutputStream} and <em>buffers</em> the output. |
| * Expensive interaction with the underlying input stream is minimized, since |
| * most (smaller) requests can be satisfied by accessing the buffer alone. The |
| * drawback is that some extra space is required to hold the buffer and that |
| * copying takes place when flushing that buffer, but this is usually outweighed |
| * by the performance benefits. |
| * |
| * <p/>A typical application pattern for the class looks like this:<p/> |
| * |
| * <pre> |
| * BufferedOutputStream buf = new BufferedOutputStream(new FileOutputStream("file.java")); |
| * </pre> |
| * |
| * @see BufferedInputStream |
| */ |
| public class BufferedOutputStream extends FilterOutputStream { |
| /** |
| * The buffer containing the bytes to be written to the target stream. |
| */ |
| protected byte[] buf; |
| |
| /** |
| * The total number of bytes inside the byte array {@code buf}. |
| */ |
| protected int count; |
| |
| /** |
| * Constructs a new {@code BufferedOutputStream} on the {@link OutputStream} |
| * {@code out}. The buffer size is set to the default value of 8 KB. |
| * |
| * @param out |
| * the {@code OutputStream} for which write operations are |
| * buffered. |
| */ |
| public BufferedOutputStream(OutputStream out) { |
| super(out); |
| buf = new byte[8192]; |
| |
| // BEGIN android-added |
| /* |
| * For Android, we want to discourage the use of this constructor (with |
| * its arguably too-large default), so we note its use in the log. We |
| * don't disable it, nor do we alter the default, however, because we |
| * still aim to behave compatibly, and the default value, though not |
| * documented, is established by convention. |
| */ |
| Logger.global.info( |
| "Default buffer size used in BufferedOutputStream " + |
| "constructor. It would be " + |
| "better to be explicit if an 8k buffer is required."); |
| // END android-added |
| } |
| |
| /** |
| * Constructs a new {@code BufferedOutputStream} on the {@link OutputStream} |
| * {@code out}. The buffer size is set to {@code size}. |
| * |
| * @param out |
| * the output stream for which write operations are buffered. |
| * @param size |
| * the size of the buffer in bytes. |
| * @throws IllegalArgumentException |
| * if {@code size <= 0}. |
| */ |
| public BufferedOutputStream(OutputStream out, int size) { |
| super(out); |
| if (size <= 0) { |
| // K0058=size must be > 0 |
| throw new IllegalArgumentException(Msg.getString("K0058")); //$NON-NLS-1$ |
| } |
| buf = new byte[size]; |
| } |
| |
| /** |
| * Flushes this stream to ensure all pending data is written out to the |
| * target stream. In addition, the target stream is flushed. |
| * |
| * @throws IOException |
| * if an error occurs attempting to flush this stream. |
| */ |
| @Override |
| public synchronized void flush() throws IOException { |
| if (buf == null) { |
| throw new IOException(Msg.getString("K0059")); //$NON-NLS-1$ |
| } |
| |
| flushInternal(); |
| out.flush(); |
| } |
| |
| /** |
| * Writes {@code count} bytes from the byte array {@code buffer} starting at |
| * {@code offset} to this stream. If there is room in the buffer to hold the |
| * bytes, they are copied in. If not, the buffered bytes plus the bytes in |
| * {@code buffer} are written to the target stream, the target is flushed, |
| * and the buffer is cleared. |
| * |
| * @param buffer |
| * the buffer to be written. |
| * @param offset |
| * the start position in {@code buffer} from where to get bytes. |
| * @param length |
| * the number of bytes from {@code buffer} to write to this |
| * stream. |
| * @throws IndexOutOfBoundsException |
| * if {@code offset < 0} or {@code length < 0}, or if |
| * {@code offset + length} is greater than the size of |
| * {@code buffer}. |
| * @throws IOException |
| * if an error occurs attempting to write to this stream. |
| * @throws NullPointerException |
| * if {@code buffer} is {@code null}. |
| * @throws ArrayIndexOutOfBoundsException |
| * If offset or count is outside of bounds. |
| */ |
| @Override |
| public synchronized void write(byte[] buffer, int offset, int length) |
| throws IOException { |
| byte[] internalBuffer = buf; |
| if (internalBuffer == null) { |
| throw new IOException(Msg.getString("K0059")); //$NON-NLS-1$ |
| } |
| |
| if (buffer == null) { |
| // K0047=buffer is null |
| throw new NullPointerException(Msg.getString("K0047")); //$NON-NLS-1$ |
| } |
| |
| if (length >= internalBuffer.length) { |
| flushInternal(); |
| out.write(buffer, offset, length); |
| return; |
| } |
| |
| if (offset < 0 || offset > buffer.length - length) { |
| // K002e=Offset out of bounds \: {0} |
| throw new ArrayIndexOutOfBoundsException(Msg.getString("K002e", offset)); //$NON-NLS-1$ |
| |
| } |
| if (length < 0) { |
| // K0031=Length out of bounds \: {0} |
| throw new ArrayIndexOutOfBoundsException(Msg.getString("K0031", length)); //$NON-NLS-1$ |
| } |
| |
| // flush the internal buffer first if we have not enough space left |
| if (length >= (internalBuffer.length - count)) { |
| flushInternal(); |
| } |
| |
| // the length is always less than (internalBuffer.length - count) here so arraycopy is safe |
| System.arraycopy(buffer, offset, internalBuffer, count, length); |
| count += length; |
| } |
| |
| @Override public synchronized void close() throws IOException { |
| if (buf == null) { |
| return; |
| } |
| |
| try { |
| super.close(); |
| } finally { |
| buf = null; |
| } |
| } |
| |
| /** |
| * Writes one byte to this stream. Only the low order byte of the integer |
| * {@code oneByte} is written. If there is room in the buffer, the byte is |
| * copied into the buffer and the count incremented. Otherwise, the buffer |
| * plus {@code oneByte} are written to the target stream, the target is |
| * flushed, and the buffer is reset. |
| * |
| * @param oneByte |
| * the byte to be written. |
| * @throws IOException |
| * if an error occurs attempting to write to this stream. |
| */ |
| @Override |
| public synchronized void write(int oneByte) throws IOException { |
| byte[] internalBuffer = buf; |
| if (internalBuffer == null) { |
| throw new IOException(Msg.getString("K0059")); //$NON-NLS-1$ |
| } |
| |
| if (count == internalBuffer.length) { |
| out.write(internalBuffer, 0, count); |
| count = 0; |
| } |
| internalBuffer[count++] = (byte) oneByte; |
| } |
| |
| /** |
| * Flushes only internal buffer. |
| */ |
| private void flushInternal() throws IOException { |
| if (count > 0) { |
| out.write(buf, 0, count); |
| count = 0; |
| } |
| } |
| } |
