| /* |
| * Copyright (c) 1994, 2017, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.io; |
| |
| import java.nio.channels.FileChannel; |
| import jdk.internal.misc.SharedSecrets; |
| import jdk.internal.misc.JavaIOFileDescriptorAccess; |
| import sun.nio.ch.FileChannelImpl; |
| |
| |
| /** |
| * A file output stream is an output stream for writing data to a |
| * <code>File</code> or to a <code>FileDescriptor</code>. Whether or not |
| * a file is available or may be created depends upon the underlying |
| * platform. Some platforms, in particular, allow a file to be opened |
| * for writing by only one {@code FileOutputStream} (or other |
| * file-writing object) at a time. In such situations the constructors in |
| * this class will fail if the file involved is already open. |
| * |
| * <p><code>FileOutputStream</code> is meant for writing streams of raw bytes |
| * such as image data. For writing streams of characters, consider using |
| * <code>FileWriter</code>. |
| * |
| * @author Arthur van Hoff |
| * @see java.io.File |
| * @see java.io.FileDescriptor |
| * @see java.io.FileInputStream |
| * @see java.nio.file.Files#newOutputStream |
| * @since 1.0 |
| */ |
| public |
| class FileOutputStream extends OutputStream |
| { |
| /** |
| * Access to FileDescriptor internals. |
| */ |
| private static final JavaIOFileDescriptorAccess fdAccess = |
| SharedSecrets.getJavaIOFileDescriptorAccess(); |
| |
| /** |
| * The system dependent file descriptor. |
| */ |
| private final FileDescriptor fd; |
| |
| /** |
| * The associated channel, initialized lazily. |
| */ |
| private volatile FileChannel channel; |
| |
| /** |
| * The path of the referenced file |
| * (null if the stream is created with a file descriptor) |
| */ |
| private final String path; |
| |
| private final Object closeLock = new Object(); |
| |
| private volatile boolean closed; |
| |
| /** |
| * Creates a file output stream to write to the file with the |
| * specified name. A new <code>FileDescriptor</code> object is |
| * created to represent this file connection. |
| * <p> |
| * First, if there is a security manager, its <code>checkWrite</code> |
| * method is called with <code>name</code> as its argument. |
| * <p> |
| * If the file exists but is a directory rather than a regular file, does |
| * not exist but cannot be created, or cannot be opened for any other |
| * reason then a <code>FileNotFoundException</code> is thrown. |
| * |
| * @implSpec Invoking this constructor with the parameter {@code name} is |
| * equivalent to invoking {@link #FileOutputStream(String,boolean) |
| * new FileOutputStream(name, false)}. |
| * |
| * @param name the system-dependent filename |
| * @exception FileNotFoundException if the file exists but is a directory |
| * rather than a regular file, does not exist but cannot |
| * be created, or cannot be opened for any other reason |
| * @exception SecurityException if a security manager exists and its |
| * <code>checkWrite</code> method denies write access |
| * to the file. |
| * @see java.lang.SecurityManager#checkWrite(java.lang.String) |
| */ |
| public FileOutputStream(String name) throws FileNotFoundException { |
| this(name != null ? new File(name) : null, false); |
| } |
| |
| /** |
| * Creates a file output stream to write to the file with the specified |
| * name. If the second argument is <code>true</code>, then |
| * bytes will be written to the end of the file rather than the beginning. |
| * A new <code>FileDescriptor</code> object is created to represent this |
| * file connection. |
| * <p> |
| * First, if there is a security manager, its <code>checkWrite</code> |
| * method is called with <code>name</code> as its argument. |
| * <p> |
| * If the file exists but is a directory rather than a regular file, does |
| * not exist but cannot be created, or cannot be opened for any other |
| * reason then a <code>FileNotFoundException</code> is thrown. |
| * |
| * @param name the system-dependent file name |
| * @param append if <code>true</code>, then bytes will be written |
| * to the end of the file rather than the beginning |
| * @exception FileNotFoundException if the file exists but is a directory |
| * rather than a regular file, does not exist but cannot |
| * be created, or cannot be opened for any other reason. |
| * @exception SecurityException if a security manager exists and its |
| * <code>checkWrite</code> method denies write access |
| * to the file. |
| * @see java.lang.SecurityManager#checkWrite(java.lang.String) |
| * @since 1.1 |
| */ |
| public FileOutputStream(String name, boolean append) |
| throws FileNotFoundException |
| { |
| this(name != null ? new File(name) : null, append); |
| } |
| |
| /** |
| * Creates a file output stream to write to the file represented by |
| * the specified <code>File</code> object. A new |
| * <code>FileDescriptor</code> object is created to represent this |
| * file connection. |
| * <p> |
| * First, if there is a security manager, its <code>checkWrite</code> |
| * method is called with the path represented by the <code>file</code> |
| * argument as its argument. |
| * <p> |
| * If the file exists but is a directory rather than a regular file, does |
| * not exist but cannot be created, or cannot be opened for any other |
| * reason then a <code>FileNotFoundException</code> is thrown. |
| * |
| * @param file the file to be opened for writing. |
| * @exception FileNotFoundException if the file exists but is a directory |
| * rather than a regular file, does not exist but cannot |
| * be created, or cannot be opened for any other reason |
| * @exception SecurityException if a security manager exists and its |
| * <code>checkWrite</code> method denies write access |
| * to the file. |
| * @see java.io.File#getPath() |
| * @see java.lang.SecurityException |
| * @see java.lang.SecurityManager#checkWrite(java.lang.String) |
| */ |
| public FileOutputStream(File file) throws FileNotFoundException { |
| this(file, false); |
| } |
| |
| /** |
| * Creates a file output stream to write to the file represented by |
| * the specified <code>File</code> object. If the second argument is |
| * <code>true</code>, then bytes will be written to the end of the file |
| * rather than the beginning. A new <code>FileDescriptor</code> object is |
| * created to represent this file connection. |
| * <p> |
| * First, if there is a security manager, its <code>checkWrite</code> |
| * method is called with the path represented by the <code>file</code> |
| * argument as its argument. |
| * <p> |
| * If the file exists but is a directory rather than a regular file, does |
| * not exist but cannot be created, or cannot be opened for any other |
| * reason then a <code>FileNotFoundException</code> is thrown. |
| * |
| * @param file the file to be opened for writing. |
| * @param append if <code>true</code>, then bytes will be written |
| * to the end of the file rather than the beginning |
| * @exception FileNotFoundException if the file exists but is a directory |
| * rather than a regular file, does not exist but cannot |
| * be created, or cannot be opened for any other reason |
| * @exception SecurityException if a security manager exists and its |
| * <code>checkWrite</code> method denies write access |
| * to the file. |
| * @see java.io.File#getPath() |
| * @see java.lang.SecurityException |
| * @see java.lang.SecurityManager#checkWrite(java.lang.String) |
| * @since 1.4 |
| */ |
| public FileOutputStream(File file, boolean append) |
| throws FileNotFoundException |
| { |
| String name = (file != null ? file.getPath() : null); |
| SecurityManager security = System.getSecurityManager(); |
| if (security != null) { |
| security.checkWrite(name); |
| } |
| if (name == null) { |
| throw new NullPointerException(); |
| } |
| if (file.isInvalid()) { |
| throw new FileNotFoundException("Invalid file path"); |
| } |
| this.fd = new FileDescriptor(); |
| fd.attach(this); |
| this.path = name; |
| |
| open(name, append); |
| } |
| |
| /** |
| * Creates a file output stream to write to the specified file |
| * descriptor, which represents an existing connection to an actual |
| * file in the file system. |
| * <p> |
| * First, if there is a security manager, its <code>checkWrite</code> |
| * method is called with the file descriptor <code>fdObj</code> |
| * argument as its argument. |
| * <p> |
| * If <code>fdObj</code> is null then a <code>NullPointerException</code> |
| * is thrown. |
| * <p> |
| * This constructor does not throw an exception if <code>fdObj</code> |
| * is {@link java.io.FileDescriptor#valid() invalid}. |
| * However, if the methods are invoked on the resulting stream to attempt |
| * I/O on the stream, an <code>IOException</code> is thrown. |
| * |
| * @param fdObj the file descriptor to be opened for writing |
| * @exception SecurityException if a security manager exists and its |
| * <code>checkWrite</code> method denies |
| * write access to the file descriptor |
| * @see java.lang.SecurityManager#checkWrite(java.io.FileDescriptor) |
| */ |
| public FileOutputStream(FileDescriptor fdObj) { |
| SecurityManager security = System.getSecurityManager(); |
| if (fdObj == null) { |
| throw new NullPointerException(); |
| } |
| if (security != null) { |
| security.checkWrite(fdObj); |
| } |
| this.fd = fdObj; |
| this.path = null; |
| |
| fd.attach(this); |
| } |
| |
| /** |
| * Opens a file, with the specified name, for overwriting or appending. |
| * @param name name of file to be opened |
| * @param append whether the file is to be opened in append mode |
| */ |
| private native void open0(String name, boolean append) |
| throws FileNotFoundException; |
| |
| // wrap native call to allow instrumentation |
| /** |
| * Opens a file, with the specified name, for overwriting or appending. |
| * @param name name of file to be opened |
| * @param append whether the file is to be opened in append mode |
| */ |
| private void open(String name, boolean append) |
| throws FileNotFoundException { |
| open0(name, append); |
| } |
| |
| /** |
| * Writes the specified byte to this file output stream. |
| * |
| * @param b the byte to be written. |
| * @param append {@code true} if the write operation first |
| * advances the position to the end of file |
| */ |
| private native void write(int b, boolean append) throws IOException; |
| |
| /** |
| * Writes the specified byte to this file output stream. Implements |
| * the <code>write</code> method of <code>OutputStream</code>. |
| * |
| * @param b the byte to be written. |
| * @exception IOException if an I/O error occurs. |
| */ |
| public void write(int b) throws IOException { |
| write(b, fdAccess.getAppend(fd)); |
| } |
| |
| /** |
| * Writes a sub array as a sequence of bytes. |
| * @param b the data to be written |
| * @param off the start offset in the data |
| * @param len the number of bytes that are written |
| * @param append {@code true} to first advance the position to the |
| * end of file |
| * @exception IOException If an I/O error has occurred. |
| */ |
| private native void writeBytes(byte b[], int off, int len, boolean append) |
| throws IOException; |
| |
| /** |
| * Writes <code>b.length</code> bytes from the specified byte array |
| * to this file output stream. |
| * |
| * @param b the data. |
| * @exception IOException if an I/O error occurs. |
| */ |
| public void write(byte b[]) throws IOException { |
| writeBytes(b, 0, b.length, fdAccess.getAppend(fd)); |
| } |
| |
| /** |
| * Writes <code>len</code> bytes from the specified byte array |
| * starting at offset <code>off</code> to this file output stream. |
| * |
| * @param b the data. |
| * @param off the start offset in the data. |
| * @param len the number of bytes to write. |
| * @exception IOException if an I/O error occurs. |
| */ |
| public void write(byte b[], int off, int len) throws IOException { |
| writeBytes(b, off, len, fdAccess.getAppend(fd)); |
| } |
| |
| /** |
| * Closes this file output stream and releases any system resources |
| * associated with this stream. This file output stream may no longer |
| * be used for writing bytes. |
| * |
| * <p> If this stream has an associated channel then the channel is closed |
| * as well. |
| * |
| * @exception IOException if an I/O error occurs. |
| * |
| * @revised 1.4 |
| * @spec JSR-51 |
| */ |
| public void close() throws IOException { |
| if (closed) { |
| return; |
| } |
| synchronized (closeLock) { |
| if (closed) { |
| return; |
| } |
| closed = true; |
| } |
| |
| FileChannel fc = channel; |
| if (fc != null) { |
| // possible race with getChannel(), benign since |
| // FileChannel.close is final and idempotent |
| fc.close(); |
| } |
| |
| fd.closeAll(new Closeable() { |
| public void close() throws IOException { |
| close0(); |
| } |
| }); |
| } |
| |
| /** |
| * Returns the file descriptor associated with this stream. |
| * |
| * @return the <code>FileDescriptor</code> object that represents |
| * the connection to the file in the file system being used |
| * by this <code>FileOutputStream</code> object. |
| * |
| * @exception IOException if an I/O error occurs. |
| * @see java.io.FileDescriptor |
| */ |
| public final FileDescriptor getFD() throws IOException { |
| if (fd != null) { |
| return fd; |
| } |
| throw new IOException(); |
| } |
| |
| /** |
| * Returns the unique {@link java.nio.channels.FileChannel FileChannel} |
| * object associated with this file output stream. |
| * |
| * <p> The initial {@link java.nio.channels.FileChannel#position() |
| * position} of the returned channel will be equal to the |
| * number of bytes written to the file so far unless this stream is in |
| * append mode, in which case it will be equal to the size of the file. |
| * Writing bytes to this stream will increment the channel's position |
| * accordingly. Changing the channel's position, either explicitly or by |
| * writing, will change this stream's file position. |
| * |
| * @return the file channel associated with this file output stream |
| * |
| * @since 1.4 |
| * @spec JSR-51 |
| */ |
| public FileChannel getChannel() { |
| FileChannel fc = this.channel; |
| if (fc == null) { |
| synchronized (this) { |
| fc = this.channel; |
| if (fc == null) { |
| this.channel = fc = FileChannelImpl.open(fd, path, false, true, this); |
| if (closed) { |
| try { |
| // possible race with close(), benign since |
| // FileChannel.close is final and idempotent |
| fc.close(); |
| } catch (IOException ioe) { |
| throw new InternalError(ioe); // should not happen |
| } |
| } |
| } |
| } |
| } |
| return fc; |
| } |
| |
| /** |
| * Cleans up the connection to the file, and ensures that the |
| * <code>close</code> method of this file output stream is |
| * called when there are no more references to this stream. |
| * |
| * @deprecated The {@code finalize} method has been deprecated. |
| * Subclasses that override {@code finalize} in order to perform cleanup |
| * should be modified to use alternative cleanup mechanisms and |
| * to remove the overriding {@code finalize} method. |
| * When overriding the {@code finalize} method, its implementation must explicitly |
| * ensure that {@code super.finalize()} is invoked as described in {@link Object#finalize}. |
| * See the specification for {@link Object#finalize()} for further |
| * information about migration options. |
| * @exception IOException if an I/O error occurs. |
| * @see java.io.FileInputStream#close() |
| */ |
| @Deprecated(since="9") |
| protected void finalize() throws IOException { |
| if (fd != null) { |
| if (fd == FileDescriptor.out || fd == FileDescriptor.err) { |
| flush(); |
| } else { |
| /* if fd is shared, the references in FileDescriptor |
| * will ensure that finalizer is only called when |
| * safe to do so. All references using the fd have |
| * become unreachable. We can call close() |
| */ |
| close(); |
| } |
| } |
| } |
| |
| private native void close0() throws IOException; |
| |
| private static native void initIDs(); |
| |
| static { |
| initIDs(); |
| } |
| |
| } |