FileOutputStream.java revision cdf7a1f942469221bcfd63d9cdf71851b011eaf0
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; 2499a89dd6f0a0e1396aa9b3feebf15ea31f703d3aElliott Hughesimport libcore.io.IoUtils; 25cdf7a1f942469221bcfd63d9cdf71851b011eaf0Elliott Hughesimport static libcore.io.OsConstants.*; 26adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectimport org.apache.harmony.luni.platform.Platform; 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 57024784c977a744708ab0bcefc4337d491e429937Jesse Wilson private final boolean shouldCloseFd; 58adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 59024784c977a744708ab0bcefc4337d491e429937Jesse Wilson /** The unique file channel. Lazily initialized because it's rarely needed. */ 60adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project private FileChannel channel; 61adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 62024784c977a744708ab0bcefc4337d491e429937Jesse Wilson /** File access mode */ 63024784c977a744708ab0bcefc4337d491e429937Jesse Wilson private final int mode; 64024784c977a744708ab0bcefc4337d491e429937Jesse Wilson 6512f2d8e2760b78c673b7a187b9062b3938a03147Brian Carlstrom private final CloseGuard guard = CloseGuard.get(); 66f7aab022dcbfcd8f27b409ab92b4bca4a84d0b8aBrian Carlstrom 67adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 68024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * Constructs a new {@code FileOutputStream} that writes to {@code file}. 69f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 70024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * @param file the file to which this stream writes. 71024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * @throws FileNotFoundException if file cannot be opened for writing. 72adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 73adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public FileOutputStream(File file) throws FileNotFoundException { 74adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project this(file, false); 75adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 76adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 77adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 78024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * Constructs a new {@code FileOutputStream} that writes to {@code file}, 79024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * creating it if necessary. If {@code append} is true and the file already 80024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * exists, it will be appended to. Otherwise a new file will be created. 81f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 82024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * @param file the file to which this stream writes. 83024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * @param append true to append to an existing file. 84024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * @throws FileNotFoundException if the file cannot be opened for writing. 85adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 86ad41624e761bcf1af9c8008eb45187fc13983717Elliott Hughes public FileOutputStream(File file, boolean append) throws FileNotFoundException { 87024784c977a744708ab0bcefc4337d491e429937Jesse Wilson this.fd = new FileDescriptor(); 88cdf7a1f942469221bcfd63d9cdf71851b011eaf0Elliott Hughes this.mode = O_WRONLY | O_CREAT | (append ? O_APPEND : O_TRUNC); 89024784c977a744708ab0bcefc4337d491e429937Jesse Wilson this.fd.descriptor = Platform.FILE_SYSTEM.open(file.getAbsolutePath(), mode); 90024784c977a744708ab0bcefc4337d491e429937Jesse Wilson this.shouldCloseFd = true; 9112f2d8e2760b78c673b7a187b9062b3938a03147Brian Carlstrom this.guard.open("close"); 92adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 93adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 94adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 95024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * Constructs a new {@code FileOutputStream} that writes to {@code fd}. 96f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 97024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * @param fd the FileDescriptor to which this stream writes. 98024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * @throws NullPointerException if {@code fd} is null. 99adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 100adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public FileOutputStream(FileDescriptor fd) { 101adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (fd == null) { 102b1396870f92135aa140bd2b86221768dea5bc11dElliott Hughes throw new NullPointerException(); 103adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 104adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project this.fd = fd; 105024784c977a744708ab0bcefc4337d491e429937Jesse Wilson this.shouldCloseFd = false; 106cdf7a1f942469221bcfd63d9cdf71851b011eaf0Elliott Hughes this.mode = O_WRONLY; 107cdf7a1f942469221bcfd63d9cdf71851b011eaf0Elliott Hughes this.channel = NioUtils.newFileChannel(this, fd.descriptor, mode); 108bd3f08d95b31543b5f1fe3d93594efc9c8a2879bBrian Carlstrom // Note that we do not call guard.open here because the 109bd3f08d95b31543b5f1fe3d93594efc9c8a2879bBrian Carlstrom // FileDescriptor is not owned by the stream. 110adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 111adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 112adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 113024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * Equivalent to {@code new FileOutputStream(new File(path), false)}. 114adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 115024784c977a744708ab0bcefc4337d491e429937Jesse Wilson public FileOutputStream(String path) throws FileNotFoundException { 116024784c977a744708ab0bcefc4337d491e429937Jesse Wilson this(path, false); 117adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 118adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 119adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 120024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * Equivalent to {@code new FileOutputStream(new File(path), append)}. 121adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 122024784c977a744708ab0bcefc4337d491e429937Jesse Wilson public FileOutputStream(String path, boolean append) throws FileNotFoundException { 123024784c977a744708ab0bcefc4337d491e429937Jesse Wilson this(new File(path), append); 124adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 125adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 126adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project @Override 127adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public void close() throws IOException { 12812f2d8e2760b78c673b7a187b9062b3938a03147Brian Carlstrom guard.close(); 129adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project synchronized (this) { 130024784c977a744708ab0bcefc4337d491e429937Jesse Wilson if (channel != null) { 131024784c977a744708ab0bcefc4337d491e429937Jesse Wilson channel.close(); 132024784c977a744708ab0bcefc4337d491e429937Jesse Wilson } 133024784c977a744708ab0bcefc4337d491e429937Jesse Wilson if (shouldCloseFd && fd.valid()) { 13499a89dd6f0a0e1396aa9b3feebf15ea31f703d3aElliott Hughes IoUtils.close(fd); 135adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 136adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 137adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 138adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 139e2f58c9501eac730d048199906dc41fe8e4cd6e9Brian Carlstrom @Override protected void finalize() throws IOException { 140024784c977a744708ab0bcefc4337d491e429937Jesse Wilson try { 14112f2d8e2760b78c673b7a187b9062b3938a03147Brian Carlstrom if (guard != null) { 14212f2d8e2760b78c673b7a187b9062b3938a03147Brian Carlstrom guard.warnIfOpen(); 14312f2d8e2760b78c673b7a187b9062b3938a03147Brian Carlstrom } 144e2f58c9501eac730d048199906dc41fe8e4cd6e9Brian Carlstrom close(); 145e2f58c9501eac730d048199906dc41fe8e4cd6e9Brian Carlstrom } finally { 146e2f58c9501eac730d048199906dc41fe8e4cd6e9Brian Carlstrom try { 147e2f58c9501eac730d048199906dc41fe8e4cd6e9Brian Carlstrom super.finalize(); 148e2f58c9501eac730d048199906dc41fe8e4cd6e9Brian Carlstrom } catch (Throwable t) { 14963fcdd7e833df417cfbd60961a5167ce637f3071Brian Carlstrom // for consistency with the RI, we must override Object.finalize() to 15063fcdd7e833df417cfbd60961a5167ce637f3071Brian Carlstrom // remove the 'throws Throwable' clause. 151e2f58c9501eac730d048199906dc41fe8e4cd6e9Brian Carlstrom throw new AssertionError(t); 152e2f58c9501eac730d048199906dc41fe8e4cd6e9Brian Carlstrom } 153024784c977a744708ab0bcefc4337d491e429937Jesse Wilson } 154adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 155adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 156adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 157024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * Returns a write-only {@link FileChannel} that shares its position with 158024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * this stream. 159adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 160adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public FileChannel getChannel() { 161024784c977a744708ab0bcefc4337d491e429937Jesse Wilson synchronized (this) { 162024784c977a744708ab0bcefc4337d491e429937Jesse Wilson if (channel == null) { 163024784c977a744708ab0bcefc4337d491e429937Jesse Wilson channel = NioUtils.newFileChannel(this, fd.descriptor, mode); 164024784c977a744708ab0bcefc4337d491e429937Jesse Wilson } 165024784c977a744708ab0bcefc4337d491e429937Jesse Wilson return channel; 166024784c977a744708ab0bcefc4337d491e429937Jesse Wilson } 167adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 168adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 169adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 170024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * Returns the underlying file descriptor. 171adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 172adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public final FileDescriptor getFD() throws IOException { 173adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return fd; 174adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 175adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 176adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project @Override 177a1603838fe9e865575c87982e32c6343740e464cElliott Hughes public void write(byte[] buffer, int offset, int byteCount) throws IOException { 178a1603838fe9e865575c87982e32c6343740e464cElliott Hughes Arrays.checkOffsetAndCount(buffer.length, offset, byteCount); 179a1603838fe9e865575c87982e32c6343740e464cElliott Hughes if (byteCount == 0) { 180adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return; 181adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 182024784c977a744708ab0bcefc4337d491e429937Jesse Wilson checkOpen(); 183a1603838fe9e865575c87982e32c6343740e464cElliott Hughes Platform.FILE_SYSTEM.write(fd.descriptor, buffer, offset, byteCount); 184adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 185adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 186adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project @Override 187adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public void write(int oneByte) throws IOException { 188024784c977a744708ab0bcefc4337d491e429937Jesse Wilson checkOpen(); 189024784c977a744708ab0bcefc4337d491e429937Jesse Wilson byte[] buffer = { (byte) oneByte }; 190024784c977a744708ab0bcefc4337d491e429937Jesse Wilson Platform.FILE_SYSTEM.write(fd.descriptor, buffer, 0, 1); 191adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 192adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 193024784c977a744708ab0bcefc4337d491e429937Jesse Wilson private synchronized void checkOpen() throws IOException { 194024784c977a744708ab0bcefc4337d491e429937Jesse Wilson if (!fd.valid()) { 195024784c977a744708ab0bcefc4337d491e429937Jesse Wilson throw new IOException("stream is closed"); 196adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 197adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 198adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project} 199