--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/io/FileInputStream.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,439 @@
+/*
+ * 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 sun.nio.ch.FileChannelImpl;
+
+
+/**
+ * A <code>FileInputStream</code> obtains input bytes
+ * from a file in a file system. What files
+ * are available depends on the host environment.
+ *
+ * <p><code>FileInputStream</code> is meant for reading streams of raw bytes
+ * such as image data. For reading streams of characters, consider using
+ * <code>FileReader</code>.
+ *
+ * @author Arthur van Hoff
+ * @see java.io.File
+ * @see java.io.FileDescriptor
+ * @see java.io.FileOutputStream
+ * @see java.nio.file.Files#newInputStream
+ * @since 1.0
+ */
+public
+class FileInputStream extends InputStream
+{
+ /* File Descriptor - handle to the open file */
+ private final FileDescriptor fd;
+
+ /**
+ * The path of the referenced file
+ * (null if the stream is created with a file descriptor)
+ */
+ private final String path;
+
+ private volatile FileChannel channel;
+
+ private final Object closeLock = new Object();
+
+ private volatile boolean closed;
+
+ /**
+ * Creates a <code>FileInputStream</code> by
+ * opening a connection to an actual file,
+ * the file named by the path name <code>name</code>
+ * in the file system. A new <code>FileDescriptor</code>
+ * object is created to represent this file
+ * connection.
+ * <p>
+ * First, if there is a security
+ * manager, its <code>checkRead</code> method
+ * is called with the <code>name</code> argument
+ * as its argument.
+ * <p>
+ * If the named file does not exist, is a directory rather than a regular
+ * file, or for some other reason cannot be opened for reading then a
+ * <code>FileNotFoundException</code> is thrown.
+ *
+ * @param name the system-dependent file name.
+ * @exception FileNotFoundException if the file does not exist,
+ * is a directory rather than a regular file,
+ * or for some other reason cannot be opened for
+ * reading.
+ * @exception SecurityException if a security manager exists and its
+ * <code>checkRead</code> method denies read access
+ * to the file.
+ * @see java.lang.SecurityManager#checkRead(java.lang.String)
+ */
+ public FileInputStream(String name) throws FileNotFoundException {
+ this(name != null ? new File(name) : null);
+ }
+
+ /**
+ * Creates a <code>FileInputStream</code> by
+ * opening a connection to an actual file,
+ * the file named by the <code>File</code>
+ * object <code>file</code> in the file system.
+ * A new <code>FileDescriptor</code> object
+ * is created to represent this file connection.
+ * <p>
+ * First, if there is a security manager,
+ * its <code>checkRead</code> method is called
+ * with the path represented by the <code>file</code>
+ * argument as its argument.
+ * <p>
+ * If the named file does not exist, is a directory rather than a regular
+ * file, or for some other reason cannot be opened for reading then a
+ * <code>FileNotFoundException</code> is thrown.
+ *
+ * @param file the file to be opened for reading.
+ * @exception FileNotFoundException if the file does not exist,
+ * is a directory rather than a regular file,
+ * or for some other reason cannot be opened for
+ * reading.
+ * @exception SecurityException if a security manager exists and its
+ * <code>checkRead</code> method denies read access to the file.
+ * @see java.io.File#getPath()
+ * @see java.lang.SecurityManager#checkRead(java.lang.String)
+ */
+ public FileInputStream(File file) throws FileNotFoundException {
+ String name = (file != null ? file.getPath() : null);
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkRead(name);
+ }
+ if (name == null) {
+ throw new NullPointerException();
+ }
+ if (file.isInvalid()) {
+ throw new FileNotFoundException("Invalid file path");
+ }
+ fd = new FileDescriptor();
+ fd.attach(this);
+ path = name;
+ open(name);
+ }
+
+ /**
+ * Creates a <code>FileInputStream</code> by using the file descriptor
+ * <code>fdObj</code>, which represents an existing connection to an
+ * actual file in the file system.
+ * <p>
+ * If there is a security manager, its <code>checkRead</code> method is
+ * called with the file descriptor <code>fdObj</code> as its argument to
+ * see if it's ok to read the file descriptor. If read access is denied
+ * to the file descriptor a <code>SecurityException</code> is thrown.
+ * <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 reading.
+ * @throws SecurityException if a security manager exists and its
+ * <code>checkRead</code> method denies read access to the
+ * file descriptor.
+ * @see SecurityManager#checkRead(java.io.FileDescriptor)
+ */
+ public FileInputStream(FileDescriptor fdObj) {
+ SecurityManager security = System.getSecurityManager();
+ if (fdObj == null) {
+ throw new NullPointerException();
+ }
+ if (security != null) {
+ security.checkRead(fdObj);
+ }
+ fd = fdObj;
+ path = null;
+
+ /*
+ * FileDescriptor is being shared by streams.
+ * Register this stream with FileDescriptor tracker.
+ */
+ fd.attach(this);
+ }
+
+ /**
+ * Opens the specified file for reading.
+ * @param name the name of the file
+ */
+ private native void open0(String name) throws FileNotFoundException;
+
+ // wrap native call to allow instrumentation
+ /**
+ * Opens the specified file for reading.
+ * @param name the name of the file
+ */
+ private void open(String name) throws FileNotFoundException {
+ open0(name);
+ }
+
+ /**
+ * Reads a byte of data from this input stream. This method blocks
+ * if no input is yet available.
+ *
+ * @return the next byte of data, or <code>-1</code> if the end of the
+ * file is reached.
+ * @exception IOException if an I/O error occurs.
+ */
+ public int read() throws IOException {
+ return read0();
+ }
+
+ private native int read0() throws IOException;
+
+ /**
+ * Reads a subarray 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
+ * @exception IOException If an I/O error has occurred.
+ */
+ private native int readBytes(byte b[], int off, int len) throws IOException;
+
+ /**
+ * Reads up to <code>b.length</code> bytes of data from this input
+ * stream into an array of bytes. This method blocks until some input
+ * is available.
+ *
+ * @param b the buffer into which the data is read.
+ * @return the total number of bytes read into the buffer, or
+ * <code>-1</code> if there is no more data because the end of
+ * the file has been reached.
+ * @exception IOException if an I/O error occurs.
+ */
+ public int read(byte b[]) throws IOException {
+ return readBytes(b, 0, b.length);
+ }
+
+ /**
+ * Reads up to <code>len</code> bytes of data from this input stream
+ * into an array of bytes. If <code>len</code> is not zero, the method
+ * blocks until some input is available; otherwise, no
+ * bytes are read and <code>0</code> is returned.
+ *
+ * @param b the buffer into which the data is read.
+ * @param off the start offset in the destination array <code>b</code>
+ * @param len the maximum number of bytes read.
+ * @return the total number of bytes read into the buffer, or
+ * <code>-1</code> if there is no more data because the end of
+ * the file has been reached.
+ * @exception NullPointerException If <code>b</code> is <code>null</code>.
+ * @exception IndexOutOfBoundsException If <code>off</code> is negative,
+ * <code>len</code> is negative, or <code>len</code> is greater than
+ * <code>b.length - off</code>
+ * @exception IOException if an I/O error occurs.
+ */
+ public int read(byte b[], int off, int len) throws IOException {
+ return readBytes(b, off, len);
+ }
+
+ /**
+ * Skips over and discards <code>n</code> bytes of data from the
+ * input stream.
+ *
+ * <p>The <code>skip</code> method may, for a variety of
+ * reasons, end up skipping over some smaller number of bytes,
+ * possibly <code>0</code>. If <code>n</code> is negative, the method
+ * will try to skip backwards. In case the backing file does not support
+ * backward skip at its current position, an <code>IOException</code> is
+ * thrown. The actual number of bytes skipped is returned. If it skips
+ * forwards, it returns a positive value. If it skips backwards, it
+ * returns a negative value.
+ *
+ * <p>This method may skip more bytes than what are remaining in the
+ * backing file. This produces no exception and the number of bytes skipped
+ * may include some number of bytes that were beyond the EOF of the
+ * backing file. Attempting to read from the stream after skipping past
+ * the end will result in -1 indicating the end of the file.
+ *
+ * @param n the number of bytes to be skipped.
+ * @return the actual number of bytes skipped.
+ * @exception IOException if n is negative, if the stream does not
+ * support seek, or if an I/O error occurs.
+ */
+ public long skip(long n) throws IOException {
+ return skip0(n);
+ }
+
+ private native long skip0(long n) throws IOException;
+
+ /**
+ * Returns an estimate of the number of remaining bytes that can be read (or
+ * skipped over) from this input stream without blocking by the next
+ * invocation of a method for this input stream. Returns 0 when the file
+ * position is beyond EOF. The next invocation might be the same thread
+ * or another thread. A single read or skip of this many bytes will not
+ * block, but may read or skip fewer bytes.
+ *
+ * <p> In some cases, a non-blocking read (or skip) may appear to be
+ * blocked when it is merely slow, for example when reading large
+ * files over slow networks.
+ *
+ * @return an estimate of the number of remaining bytes that can be read
+ * (or skipped over) from this input stream without blocking.
+ * @exception IOException if this file input stream has been closed by calling
+ * {@code close} or an I/O error occurs.
+ */
+ public int available() throws IOException {
+ return available0();
+ }
+
+ private native int available0() throws IOException;
+
+ /**
+ * Closes this file input stream and releases any system resources
+ * associated with the stream.
+ *
+ * <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 <code>FileDescriptor</code>
+ * object that represents the connection to
+ * the actual file in the file system being
+ * used by this <code>FileInputStream</code>.
+ *
+ * @return the file descriptor object associated with this stream.
+ * @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 input stream.
+ *
+ * <p> The initial {@link java.nio.channels.FileChannel#position()
+ * position} of the returned channel will be equal to the
+ * number of bytes read from the file so far. Reading bytes from this
+ * stream will increment the channel's position. Changing the channel's
+ * position, either explicitly or by reading, will change this stream's
+ * file position.
+ *
+ * @return the file channel associated with this file input 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, true, false, 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;
+ }
+
+ private static native void initIDs();
+
+ private native void close0() throws IOException;
+
+ static {
+ initIDs();
+ }
+
+ /**
+ * Ensures that the <code>close</code> method of this file input stream is
+ * called when there are no more references to it.
+ *
+ * @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) && (fd != FileDescriptor.in)) {
+ /* 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();
+ }
+ }
+}