FileOutputStream.java revision 462bdac45c10f43d88d8f07f6994e272a27c14a2
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 Project 27adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project/** 28024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * An output stream that writes bytes to a file. If the output file exists, it 29024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * can be replaced or appended to. If it does not exist, a new file will be 30024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * created. 31024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * <pre> {@code 32024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * File file = ... 33024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * OutputStream out = null; 34024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * try { 35024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * out = new BufferedOutputStream(new FileOutputStream(file)); 36024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * ... 37024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * } finally { 38024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * if (out != null) { 39024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * out.close(); 40024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * } 41024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * } 42024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * }</pre> 43024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * 44024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * <p>This stream is <strong>not buffered</strong>. Most callers should wrap 45024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * this stream with a {@link BufferedOutputStream}. 46024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * 47024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * <p>Use {@link FileWriter} to write characters, as opposed to bytes, to a file. 48f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 49adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @see BufferedOutputStream 50adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @see FileInputStream 51adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 52adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectpublic class FileOutputStream extends OutputStream implements Closeable { 53adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 54024784c977a744708ab0bcefc4337d491e429937Jesse Wilson private final FileDescriptor fd; 55adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 56462bdac45c10f43d88d8f07f6994e272a27c14a2Elliott Hughes /** The same as 'fd' if we own the file descriptor, null otherwise. */ 57462bdac45c10f43d88d8f07f6994e272a27c14a2Elliott Hughes private final FileDescriptor ownedFd; 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 { 87462bdac45c10f43d88d8f07f6994e272a27c14a2Elliott Hughes if (file == null) { 88462bdac45c10f43d88d8f07f6994e272a27c14a2Elliott Hughes throw new NullPointerException("file == null"); 89462bdac45c10f43d88d8f07f6994e272a27c14a2Elliott Hughes } 90cdf7a1f942469221bcfd63d9cdf71851b011eaf0Elliott Hughes this.mode = O_WRONLY | O_CREAT | (append ? O_APPEND : O_TRUNC); 910ac77ac8e915bff1a863e371f9b363033f9cf759Elliott Hughes this.fd = IoUtils.open(file.getAbsolutePath(), mode); 92462bdac45c10f43d88d8f07f6994e272a27c14a2Elliott Hughes this.ownedFd = fd; 9312f2d8e2760b78c673b7a187b9062b3938a03147Brian Carlstrom this.guard.open("close"); 94adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 95adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 96adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 97024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * Constructs a new {@code FileOutputStream} that writes to {@code fd}. 98f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 99024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * @param fd the FileDescriptor to which this stream writes. 100024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * @throws NullPointerException if {@code fd} is null. 101adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 102adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public FileOutputStream(FileDescriptor fd) { 103adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (fd == null) { 104462bdac45c10f43d88d8f07f6994e272a27c14a2Elliott Hughes throw new NullPointerException("fd == null"); 105adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 106adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project this.fd = fd; 107462bdac45c10f43d88d8f07f6994e272a27c14a2Elliott Hughes this.ownedFd = null; 108cdf7a1f942469221bcfd63d9cdf71851b011eaf0Elliott Hughes this.mode = O_WRONLY; 10952724d3ebd4ccaaa4b9f5576e329d4272cde8ea9Elliott Hughes this.channel = NioUtils.newFileChannel(this, fd, mode); 110bd3f08d95b31543b5f1fe3d93594efc9c8a2879bBrian Carlstrom // Note that we do not call guard.open here because the 111bd3f08d95b31543b5f1fe3d93594efc9c8a2879bBrian Carlstrom // FileDescriptor is not owned by the stream. 112adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 113adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 114adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 115024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * Equivalent to {@code new FileOutputStream(new File(path), false)}. 116adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 117024784c977a744708ab0bcefc4337d491e429937Jesse Wilson public FileOutputStream(String path) throws FileNotFoundException { 118024784c977a744708ab0bcefc4337d491e429937Jesse Wilson this(path, false); 119adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 120adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 121adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 122024784c977a744708ab0bcefc4337d491e429937Jesse Wilson * Equivalent to {@code new FileOutputStream(new File(path), append)}. 123adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 124024784c977a744708ab0bcefc4337d491e429937Jesse Wilson public FileOutputStream(String path, boolean append) throws FileNotFoundException { 125024784c977a744708ab0bcefc4337d491e429937Jesse Wilson this(new File(path), append); 126adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 127adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 128adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project @Override 129adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public void close() throws IOException { 13012f2d8e2760b78c673b7a187b9062b3938a03147Brian Carlstrom guard.close(); 131adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project synchronized (this) { 132024784c977a744708ab0bcefc4337d491e429937Jesse Wilson if (channel != null) { 133024784c977a744708ab0bcefc4337d491e429937Jesse Wilson channel.close(); 134024784c977a744708ab0bcefc4337d491e429937Jesse Wilson } 135462bdac45c10f43d88d8f07f6994e272a27c14a2Elliott Hughes IoUtils.close(fd); 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) { 16352724d3ebd4ccaaa4b9f5576e329d4272cde8ea9Elliott Hughes channel = NioUtils.newFileChannel(this, fd, 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 17778c7cc547101002b9f9043cf3845970719d1bda8Elliott Hughes public void write(byte[] buffer, int byteOffset, int byteCount) throws IOException { 17878c7cc547101002b9f9043cf3845970719d1bda8Elliott Hughes IoUtils.write(fd, buffer, byteOffset, byteCount); 179adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 180adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 181adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project @Override 182adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public void write(int oneByte) throws IOException { 18326c7025a7a919044771fb89031161bd26fe03032Elliott Hughes write(new byte[] { (byte) oneByte }, 0, 1); 184adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 185adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project} 186