FileOutputStream.java revision 0b736ebc4efef64f2db1999aea90297ad8196146
1adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project/* 2adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Licensed to the Apache Software Foundation (ASF) under one or more 3adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * contributor license agreements. See the NOTICE file distributed with 4adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * this work for additional information regarding copyright ownership. 5adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * The ASF licenses this file to You under the Apache License, Version 2.0 6adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * (the "License"); you may not use this file except in compliance with 7adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * the License. You may obtain a copy of the License at 8adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * 9adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * http://www.apache.org/licenses/LICENSE-2.0 10adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * 11adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Unless required by applicable law or agreed to in writing, software 12adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * distributed under the License is distributed on an "AS IS" BASIS, 13adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * See the License for the specific language governing permissions and 15adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * limitations under the License. 16adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 17adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 18adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectpackage java.io; 19adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 20f7aab022dcbfcd8f27b409ab92b4bca4a84d0b8aBrian Carlstromimport dalvik.system.CloseGuard; 21ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughesimport java.nio.NioUtils; 22adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectimport java.nio.channels.FileChannel; 23a1603838fe9e865575c87982e32c6343740e464cElliott Hughesimport java.util.Arrays; 240b736ebc4efef64f2db1999aea90297ad8196146Elliott Hughesimport libcore.io.IoBridge; 2599a89dd6f0a0e1396aa9b3feebf15ea31f703d3aElliott Hughesimport libcore.io.IoUtils; 26cdf7a1f942469221bcfd63d9cdf71851b011eaf0Elliott Hughesimport static libcore.io.OsConstants.*; 27adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 28adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project/** 29024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * An output stream that writes bytes to a file. If the output file exists, it 30024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * can be replaced or appended to. If it does not exist, a new file will be 31024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * created. 32024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * <pre> {@code 33024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * File file = ... 34024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * OutputStream out = null; 35024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * try { 36024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * out = new BufferedOutputStream(new FileOutputStream(file)); 37024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * ... 38024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * } finally { 39024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * if (out != null) { 40024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * out.close(); 41024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * } 42024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * } 43024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * }</pre> 44024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * 45024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * <p>This stream is <strong>not buffered</strong>. Most callers should wrap 46024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * this stream with a {@link BufferedOutputStream}. 47024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * 48024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * <p>Use {@link FileWriter} to write characters, as opposed to bytes, to a file. 49f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 50adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @see BufferedOutputStream 51adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @see FileInputStream 52adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 53adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectpublic class FileOutputStream extends OutputStream implements Closeable { 54adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 55024784c977a744708ab0bcefc4337d491e429937Jesse Wilson private final FileDescriptor fd; 56adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 57462bdac45c10f43d88d8f07f6994e272a27c14a2Elliott Hughes /** The same as 'fd' if we own the file descriptor, null otherwise. */ 58462bdac45c10f43d88d8f07f6994e272a27c14a2Elliott Hughes private final FileDescriptor ownedFd; 59adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 60024784c977a744708ab0bcefc4337d491e429937Jesse Wilson /** The unique file channel. Lazily initialized because it's rarely needed. */ 61adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project private FileChannel channel; 62adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 63024784c977a744708ab0bcefc4337d491e429937Jesse Wilson /** File access mode */ 64024784c977a744708ab0bcefc4337d491e429937Jesse Wilson private final int mode; 65024784c977a744708ab0bcefc4337d491e429937Jesse Wilson 6612f2d8e2760b78c673b7a187b9062b3938a03147Brian Carlstrom private final CloseGuard guard = CloseGuard.get(); 67f7aab022dcbfcd8f27b409ab92b4bca4a84d0b8aBrian Carlstrom 68adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 69024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * Constructs a new {@code FileOutputStream} that writes to {@code file}. 70f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 71024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * @param file the file to which this stream writes. 72024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * @throws FileNotFoundException if file cannot be opened for writing. 73adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 74adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public FileOutputStream(File file) throws FileNotFoundException { 75adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project this(file, false); 76adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 77adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 78adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 79024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * Constructs a new {@code FileOutputStream} that writes to {@code file}, 80024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * creating it if necessary. If {@code append} is true and the file already 81024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * exists, it will be appended to. Otherwise a new file will be created. 82f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 83024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * @param file the file to which this stream writes. 84024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * @param append true to append to an existing file. 85024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * @throws FileNotFoundException if the file cannot be opened for writing. 86adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 87ad41624e761bcf1af9c8008eb45187fc13983717Elliott Hughes public FileOutputStream(File file, boolean append) throws FileNotFoundException { 88462bdac45c10f43d88d8f07f6994e272a27c14a2Elliott Hughes if (file == null) { 89462bdac45c10f43d88d8f07f6994e272a27c14a2Elliott Hughes throw new NullPointerException("file == null"); 90462bdac45c10f43d88d8f07f6994e272a27c14a2Elliott Hughes } 91cdf7a1f942469221bcfd63d9cdf71851b011eaf0Elliott Hughes this.mode = O_WRONLY | O_CREAT | (append ? O_APPEND : O_TRUNC); 920b736ebc4efef64f2db1999aea90297ad8196146Elliott Hughes this.fd = IoBridge.open(file.getAbsolutePath(), mode); 93462bdac45c10f43d88d8f07f6994e272a27c14a2Elliott Hughes this.ownedFd = fd; 9412f2d8e2760b78c673b7a187b9062b3938a03147Brian Carlstrom this.guard.open("close"); 95adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 96adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 97adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 98024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * Constructs a new {@code FileOutputStream} that writes to {@code fd}. 99f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 100024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * @param fd the FileDescriptor to which this stream writes. 101024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * @throws NullPointerException if {@code fd} is null. 102adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 103adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public FileOutputStream(FileDescriptor fd) { 104adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (fd == null) { 105462bdac45c10f43d88d8f07f6994e272a27c14a2Elliott Hughes throw new NullPointerException("fd == null"); 106adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 107adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project this.fd = fd; 108462bdac45c10f43d88d8f07f6994e272a27c14a2Elliott Hughes this.ownedFd = null; 109cdf7a1f942469221bcfd63d9cdf71851b011eaf0Elliott Hughes this.mode = O_WRONLY; 11052724d3ebd4ccaaa4b9f5576e329d4272cde8ea9Elliott Hughes this.channel = NioUtils.newFileChannel(this, fd, mode); 111bd3f08d95b31543b5f1fe3d93594efc9c8a2879bBrian Carlstrom // Note that we do not call guard.open here because the 112bd3f08d95b31543b5f1fe3d93594efc9c8a2879bBrian Carlstrom // FileDescriptor is not owned by the stream. 113adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 114adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 115adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 116024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * Equivalent to {@code new FileOutputStream(new File(path), false)}. 117adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 118024784c977a744708ab0bcefc4337d491e429937Jesse Wilson public FileOutputStream(String path) throws FileNotFoundException { 119024784c977a744708ab0bcefc4337d491e429937Jesse Wilson this(path, false); 120adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 121adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 122adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 123024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * Equivalent to {@code new FileOutputStream(new File(path), append)}. 124adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 125024784c977a744708ab0bcefc4337d491e429937Jesse Wilson public FileOutputStream(String path, boolean append) throws FileNotFoundException { 126024784c977a744708ab0bcefc4337d491e429937Jesse Wilson this(new File(path), append); 127adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 128adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 129adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project @Override 130adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public void close() throws IOException { 13112f2d8e2760b78c673b7a187b9062b3938a03147Brian Carlstrom guard.close(); 132adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project synchronized (this) { 133024784c977a744708ab0bcefc4337d491e429937Jesse Wilson if (channel != null) { 134024784c977a744708ab0bcefc4337d491e429937Jesse Wilson channel.close(); 135024784c977a744708ab0bcefc4337d491e429937Jesse Wilson } 13673298fc8f21a2440b4848912e95a072713b93a1aElliott Hughes IoUtils.close(ownedFd); 137adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 138adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 139adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 140e2f58c9501eac730d048199906dc41fe8e4cd6e9Brian Carlstrom @Override protected void finalize() throws IOException { 141024784c977a744708ab0bcefc4337d491e429937Jesse Wilson try { 14212f2d8e2760b78c673b7a187b9062b3938a03147Brian Carlstrom if (guard != null) { 14312f2d8e2760b78c673b7a187b9062b3938a03147Brian Carlstrom guard.warnIfOpen(); 14412f2d8e2760b78c673b7a187b9062b3938a03147Brian Carlstrom } 145e2f58c9501eac730d048199906dc41fe8e4cd6e9Brian Carlstrom close(); 146e2f58c9501eac730d048199906dc41fe8e4cd6e9Brian Carlstrom } finally { 147e2f58c9501eac730d048199906dc41fe8e4cd6e9Brian Carlstrom try { 148e2f58c9501eac730d048199906dc41fe8e4cd6e9Brian Carlstrom super.finalize(); 149e2f58c9501eac730d048199906dc41fe8e4cd6e9Brian Carlstrom } catch (Throwable t) { 15063fcdd7e833df417cfbd60961a5167ce637f3071Brian Carlstrom // for consistency with the RI, we must override Object.finalize() to 15163fcdd7e833df417cfbd60961a5167ce637f3071Brian Carlstrom // remove the 'throws Throwable' clause. 152e2f58c9501eac730d048199906dc41fe8e4cd6e9Brian Carlstrom throw new AssertionError(t); 153e2f58c9501eac730d048199906dc41fe8e4cd6e9Brian Carlstrom } 154024784c977a744708ab0bcefc4337d491e429937Jesse Wilson } 155adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 156adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 157adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 158024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * Returns a write-only {@link FileChannel} that shares its position with 159024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * this stream. 160adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 161adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public FileChannel getChannel() { 162024784c977a744708ab0bcefc4337d491e429937Jesse Wilson synchronized (this) { 163024784c977a744708ab0bcefc4337d491e429937Jesse Wilson if (channel == null) { 16452724d3ebd4ccaaa4b9f5576e329d4272cde8ea9Elliott Hughes channel = NioUtils.newFileChannel(this, fd, mode); 165024784c977a744708ab0bcefc4337d491e429937Jesse Wilson } 166024784c977a744708ab0bcefc4337d491e429937Jesse Wilson return channel; 167024784c977a744708ab0bcefc4337d491e429937Jesse Wilson } 168adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 169adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 170adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 171024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * Returns the underlying file descriptor. 172adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 173adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public final FileDescriptor getFD() throws IOException { 174adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return fd; 175adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 176adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 177adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project @Override 17878c7cc547101002b9f9043cf3845970719d1bda8Elliott Hughes public void write(byte[] buffer, int byteOffset, int byteCount) throws IOException { 1790b736ebc4efef64f2db1999aea90297ad8196146Elliott Hughes IoBridge.write(fd, buffer, byteOffset, byteCount); 180adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 181adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 182adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project @Override 183adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public void write(int oneByte) throws IOException { 18426c7025a7a919044771fb89031161bd26fe03032Elliott Hughes write(new byte[] { (byte) oneByte }, 0, 1); 185adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 186adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project} 187