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	/*
	* Copyright (c) 1994, 2013, 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;


	/**
	* Instances of this class support both reading and writing to a
	* random access file. A random access file behaves like a large
	* array of bytes stored in the file system. There is a kind of cursor,
	* or index into the implied array, called the <em>file pointer</em>;
	* input operations read bytes starting at the file pointer and advance
	* the file pointer past the bytes read. If the random access file is
	* created in read/write mode, then output operations are also available;
	* output operations write bytes starting at the file pointer and advance
	* the file pointer past the bytes written. Output operations that write
	* past the current end of the implied array cause the array to be
	* extended. The file pointer can be read by the
	* {@code getFilePointer} method and set by the {@code seek}
	* method.
	* <p>
	* It is generally true of all the reading routines in this class that
	* if end-of-file is reached before the desired number of bytes has been
	* read, an {@code EOFException} (which is a kind of
	* {@code IOException}) is thrown. If any byte cannot be read for
	* any reason other than end-of-file, an {@code IOException} other
	* than {@code EOFException} is thrown. In particular, an
	* {@code IOException} may be thrown if the stream has been closed.
	*
	* @author unascribed
	* @since JDK1.0
	*/

	public class RandomAccessFile implements DataOutput, DataInput, Closeable {

	private FileDescriptor fd;
	private FileChannel channel = null;
	private boolean rw;

	/**
	* The path of the referenced file
	* (null if the stream is created with a file descriptor)
	*/
	private final String path;

	private Object closeLock = new Object();
	private volatile boolean closed = false;

	private static final int O_RDONLY = 1;
	private static final int O_RDWR = 2;
	private static final int O_SYNC = 4;
	private static final int O_DSYNC = 8;

	/**
	* Creates a random access file stream to read from, and optionally
	* to write to, a file with the specified name. A new
	* {@link FileDescriptor} object is created to represent the
	* connection to the file.
	*
	* <p> The <tt>mode</tt> argument specifies the access mode with which the
	* file is to be opened. The permitted values and their meanings are as
	* specified for the <a
	* href="#mode"><tt>RandomAccessFile(File,String)</tt></a> constructor.
	*
	* <p>
	* If there is a security manager, its {@code checkRead} method
	* is called with the {@code name} argument
	* as its argument to see if read access to the file is allowed.
	* If the mode allows writing, the security manager's
	* {@code checkWrite} method
	* is also called with the {@code name} argument
	* as its argument to see if write access to the file is allowed.
	*
	* @param name the system-dependent filename
	* @param mode the access <a href="#mode">mode</a>
	* @exception IllegalArgumentException if the mode argument is not equal
	* to one of <tt>"r"</tt>, <tt>"rw"</tt>, <tt>"rws"</tt>, or
	* <tt>"rwd"</tt>
	* @exception FileNotFoundException
	* if the mode is <tt>"r"</tt> but the given string does not
	* denote an existing regular file, or if the mode begins with
	* <tt>"rw"</tt> but the given string does not denote an
	* existing, writable regular file and a new regular file of
	* that name cannot be created, or if some other error occurs
	* while opening or creating the file
	* @exception SecurityException if a security manager exists and its
	* {@code checkRead} method denies read access to the file
	* or the mode is "rw" and the security manager's
	* {@code checkWrite} method denies write access to the file
	* @see java.lang.SecurityException
	* @see java.lang.SecurityManager#checkRead(java.lang.String)
	* @see java.lang.SecurityManager#checkWrite(java.lang.String)
	* @revised 1.4
	* @spec JSR-51
	*/
	public RandomAccessFile(String name, String mode)
	throws FileNotFoundException
	{
	this(name != null ? new File(name) : null, mode);
	}

	/**
	* Creates a random access file stream to read from, and optionally to
	* write to, the file specified by the {@link File} argument. A new {@link
	* FileDescriptor} object is created to represent this file connection.
	*
	* <p>The <a name="mode"><tt>mode</tt></a> argument specifies the access mode
	* in which the file is to be opened. The permitted values and their
	* meanings are:
	*
	* <table summary="Access mode permitted values and meanings">
	* <tr><th align="left">Value</th><th align="left">Meaning</th></tr>
	* <tr><td valign="top"><tt>"r"</tt></td>
	* <td> Open for reading only. Invoking any of the <tt>write</tt>
	* methods of the resulting object will cause an {@link
	* java.io.IOException} to be thrown. </td></tr>
	* <tr><td valign="top"><tt>"rw"</tt></td>
	* <td> Open for reading and writing. If the file does not already
	* exist then an attempt will be made to create it. </td></tr>
	* <tr><td valign="top"><tt>"rws"</tt></td>
	* <td> Open for reading and writing, as with <tt>"rw"</tt>, and also
	* require that every update to the file's content or metadata be
	* written synchronously to the underlying storage device. </td></tr>
	* <tr><td valign="top"><tt>"rwd"  </tt></td>
	* <td> Open for reading and writing, as with <tt>"rw"</tt>, and also
	* require that every update to the file's content be written
	* synchronously to the underlying storage device. </td></tr>
	* </table>
	*
	* The <tt>"rws"</tt> and <tt>"rwd"</tt> modes work much like the {@link
	* java.nio.channels.FileChannel#force(boolean) force(boolean)} method of
	* the {@link java.nio.channels.FileChannel} class, passing arguments of
	* <tt>true</tt> and <tt>false</tt>, respectively, except that they always
	* apply to every I/O operation and are therefore often more efficient. If
	* the file resides on a local storage device then when an invocation of a
	* method of this class returns it is guaranteed that all changes made to
	* the file by that invocation will have been written to that device. This
	* is useful for ensuring that critical information is not lost in the
	* event of a system crash. If the file does not reside on a local device
	* then no such guarantee is made.
	*
	* <p>The <tt>"rwd"</tt> mode can be used to reduce the number of I/O
	* operations performed. Using <tt>"rwd"</tt> only requires updates to the
	* file's content to be written to storage; using <tt>"rws"</tt> requires
	* updates to both the file's content and its metadata to be written, which
	* generally requires at least one more low-level I/O operation.
	*
	* <p>If there is a security manager, its {@code checkRead} method is
	* called with the pathname of the {@code file} argument as its
	* argument to see if read access to the file is allowed. If the mode
	* allows writing, the security manager's {@code checkWrite} method is
	* also called with the path argument to see if write access to the file is
	* allowed.
	*
	* @param file the file object
	* @param mode the access mode, as described
	* <a href="#mode">above</a>
	* @exception IllegalArgumentException if the mode argument is not equal
	* to one of <tt>"r"</tt>, <tt>"rw"</tt>, <tt>"rws"</tt>, or
	* <tt>"rwd"</tt>
	* @exception FileNotFoundException
	* if the mode is <tt>"r"</tt> but the given file object does
	* not denote an existing regular file, or if the mode begins
	* with <tt>"rw"</tt> but the given file object does not denote
	* an existing, writable regular file and a new regular file of
	* that name cannot be created, or if some other error occurs
	* while opening or creating the file
	* @exception SecurityException if a security manager exists and its
	* {@code checkRead} method denies read access to the file
	* or the mode is "rw" and the security manager's
	* {@code checkWrite} method denies write access to the file
	* @see java.lang.SecurityManager#checkRead(java.lang.String)
	* @see java.lang.SecurityManager#checkWrite(java.lang.String)
	* @see java.nio.channels.FileChannel#force(boolean)
	* @revised 1.4
	* @spec JSR-51
	*/
	public RandomAccessFile(File file, String mode)
	throws FileNotFoundException
	{
	String name = (file != null ? file.getPath() : null);
	int imode = -1;
	if (mode.equals("r"))
	imode = O_RDONLY;
	else if (mode.startsWith("rw")) {
	imode = O_RDWR;
	rw = true;
	if (mode.length() > 2) {
	if (mode.equals("rws"))
	imode \|= O_SYNC;
	else if (mode.equals("rwd"))
	imode \|= O_DSYNC;
	else
	imode = -1;
	}
	}
	if (imode < 0)
	throw new IllegalArgumentException("Illegal mode \"" + mode
	+ "\" must be one of "
	+ "\"r\", \"rw\", \"rws\","
	+ " or \"rwd\"");
	SecurityManager security = System.getSecurityManager();
	if (security != null) {
	security.checkRead(name);
	if (rw) {
	security.checkWrite(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, imode);
	}

	/**
	* Returns the opaque file descriptor object associated with this
	* stream.
	*
	* @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.
	*
	* <p> The {@link java.nio.channels.FileChannel#position()
	* position} of the returned channel will always be equal to
	* this object's file-pointer offset as returned by the {@link
	* #getFilePointer getFilePointer} method. Changing this object's
	* file-pointer offset, whether explicitly or by reading or writing bytes,
	* will change the position of the channel, and vice versa. Changing the
	* file's length via this object will change the length seen via the file
	* channel, and vice versa.
	*
	* @return the file channel associated with this file
	*
	* @since 1.4
	* @spec JSR-51
	*/
	public final FileChannel getChannel() {
	synchronized (this) {
	if (channel == null) {
	channel = FileChannelImpl.open(fd, path, true, rw, this);
	}
	return channel;
	}
	}

	/**
	* Opens a file and returns the file descriptor. The file is
	* opened in read-write mode if the O_RDWR bit in {@code mode}
	* is true, else the file is opened as read-only.
	* If the {@code name} refers to a directory, an IOException
	* is thrown.
	*
	* @param name the name of the file
	* @param mode the mode flags, a combination of the O_ constants
	* defined above
	*/
	private native void open0(String name, int mode)
	throws FileNotFoundException;

	// wrap native call to allow instrumentation
	/**
	* Opens a file and returns the file descriptor. The file is
	* opened in read-write mode if the O_RDWR bit in {@code mode}
	* is true, else the file is opened as read-only.
	* If the {@code name} refers to a directory, an IOException
	* is thrown.
	*
	* @param name the name of the file
	* @param mode the mode flags, a combination of the O_ constants
	* defined above
	*/
	private void open(String name, int mode)
	throws FileNotFoundException {
	open0(name, mode);
	}

	// 'Read' primitives

	/**
	* Reads a byte of data from this file. The byte is returned as an
	* integer in the range 0 to 255 ({@code 0x00-0x0ff}). This
	* method blocks if no input is yet available.
	* <p>
	* Although {@code RandomAccessFile} is not a subclass of
	* {@code InputStream}, this method behaves in exactly the same
	* way as the {@link InputStream#read()} method of
	* {@code InputStream}.
	*
	* @return the next byte of data, or {@code -1} if the end of the
	* file has been reached.
	* @exception IOException if an I/O error occurs. Not thrown if
	* end-of-file has been reached.
	*/
	public int read() throws IOException {
	return read0();
	}

	private native int read0() throws IOException;

	/**
	* Reads a sub array as a sequence of bytes.
	* @param b the buffer into which the data is read.
	* @param off the start offset of the data.
	* @param len the number of bytes to read.
	* @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 len} bytes of data from this file into an
	* array of bytes. This method blocks until at least one byte of input
	* is available.
	* <p>
	* Although {@code RandomAccessFile} is not a subclass of
	* {@code InputStream}, this method behaves in exactly the
	* same way as the {@link InputStream#read(byte[], int, int)} method of
	* {@code InputStream}.
	*
	* @param b the buffer into which the data is read.
	* @param off the start offset in array {@code b}
	* at which the data is written.
	* @param len the maximum number of bytes read.
	* @return the total number of bytes read into the buffer, or
	* {@code -1} if there is no more data because the end of
	* the file has been reached.
	* @exception IOException If the first byte cannot be read for any reason
	* other than end of file, or if the random access file has been closed, or if
	* some other I/O error occurs.
	* @exception NullPointerException If {@code b} is {@code null}.
	* @exception IndexOutOfBoundsException If {@code off} is negative,
	* {@code len} is negative, or {@code len} is greater than
	* {@code b.length - off}
	*/
	public int read(byte b[], int off, int len) throws IOException {
	return readBytes(b, off, len);
	}

	/**
	* Reads up to {@code b.length} bytes of data from this file
	* into an array of bytes. This method blocks until at least one byte
	* of input is available.
	* <p>
	* Although {@code RandomAccessFile} is not a subclass of
	* {@code InputStream}, this method behaves in exactly the
	* same way as the {@link InputStream#read(byte[])} method of
	* {@code InputStream}.
	*
	* @param b the buffer into which the data is read.
	* @return the total number of bytes read into the buffer, or
	* {@code -1} if there is no more data because the end of
	* this file has been reached.
	* @exception IOException If the first byte cannot be read for any reason
	* other than end of file, or if the random access file has been closed, or if
	* some other I/O error occurs.
	* @exception NullPointerException If {@code b} is {@code null}.
	*/
	public int read(byte b[]) throws IOException {
	return readBytes(b, 0, b.length);
	}

	/**
	* Reads {@code b.length} bytes from this file into the byte
	* array, starting at the current file pointer. This method reads
	* repeatedly from the file until the requested number of bytes are
	* read. This method blocks until the requested number of bytes are
	* read, the end of the stream is detected, or an exception is thrown.
	*
	* @param b the buffer into which the data is read.
	* @exception EOFException if this file reaches the end before reading
	* all the bytes.
	* @exception IOException if an I/O error occurs.
	*/
	public final void readFully(byte b[]) throws IOException {
	readFully(b, 0, b.length);
	}

	/**
	* Reads exactly {@code len} bytes from this file into the byte
	* array, starting at the current file pointer. This method reads
	* repeatedly from the file until the requested number of bytes are
	* read. This method blocks until the requested number of bytes are
	* read, the end of the stream is detected, or an exception is thrown.
	*
	* @param b the buffer into which the data is read.
	* @param off the start offset of the data.
	* @param len the number of bytes to read.
	* @exception EOFException if this file reaches the end before reading
	* all the bytes.
	* @exception IOException if an I/O error occurs.
	*/
	public final void readFully(byte b[], int off, int len) throws IOException {
	int n = 0;
	do {
	int count = this.read(b, off + n, len - n);
	if (count < 0)
	throw new EOFException();
	n += count;
	} while (n < len);
	}

	/**
	* Attempts to skip over {@code n} bytes of input discarding the
	* skipped bytes.
	* <p>
	*
	* This method may skip over some smaller number of bytes, possibly zero.
	* This may result from any of a number of conditions; reaching end of
	* file before {@code n} bytes have been skipped is only one
	* possibility. This method never throws an {@code EOFException}.
	* The actual number of bytes skipped is returned. If {@code n}
	* is negative, no bytes are skipped.
	*
	* @param n the number of bytes to be skipped.
	* @return the actual number of bytes skipped.
	* @exception IOException if an I/O error occurs.
	*/
	public int skipBytes(int n) throws IOException {
	long pos;
	long len;
	long newpos;

	if (n <= 0) {
	return 0;
	}
	pos = getFilePointer();
	len = length();
	newpos = pos + n;
	if (newpos > len) {
	newpos = len;
	}
	seek(newpos);

	/* return the actual number of bytes skipped */
	return (int) (newpos - pos);
	}

	// 'Write' primitives

	/**
	* Writes the specified byte to this file. The write starts at
	* the current file pointer.
	*
	* @param b the {@code byte} to be written.
	* @exception IOException if an I/O error occurs.
	*/
	public void write(int b) throws IOException {
	write0(b);
	}

	private native void write0(int b) throws IOException;

	/**
	* 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
	* @exception IOException If an I/O error has occurred.
	*/
	private native void writeBytes(byte b[], int off, int len) throws IOException;

	/**
	* Writes {@code b.length} bytes from the specified byte array
	* to this file, starting at the current file pointer.
	*
	* @param b the data.
	* @exception IOException if an I/O error occurs.
	*/
	public void write(byte b[]) throws IOException {
	writeBytes(b, 0, b.length);
	}

	/**
	* Writes {@code len} bytes from the specified byte array
	* starting at offset {@code off} to this file.
	*
	* @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);
	}

	// 'Random access' stuff

	/**
	* Returns the current offset in this file.
	*
	* @return the offset from the beginning of the file, in bytes,
	* at which the next read or write occurs.
	* @exception IOException if an I/O error occurs.
	*/
	public native long getFilePointer() throws IOException;

	/**
	* Sets the file-pointer offset, measured from the beginning of this
	* file, at which the next read or write occurs. The offset may be
	* set beyond the end of the file. Setting the offset beyond the end
	* of the file does not change the file length. The file length will
	* change only by writing after the offset has been set beyond the end
	* of the file.
	*
	* @param pos the offset position, measured in bytes from the
	* beginning of the file, at which to set the file
	* pointer.
	* @exception IOException if {@code pos} is less than
	* {@code 0} or if an I/O error occurs.
	*/
	public void seek(long pos) throws IOException {
	if (pos < 0) {
	throw new IOException("Negative seek offset");
	} else {
	seek0(pos);
	}
	}

	private native void seek0(long pos) throws IOException;

	/**
	* Returns the length of this file.
	*
	* @return the length of this file, measured in bytes.
	* @exception IOException if an I/O error occurs.
	*/
	public native long length() throws IOException;

	/**
	* Sets the length of this file.
	*
	* <p> If the present length of the file as returned by the
	* {@code length} method is greater than the {@code newLength}
	* argument then the file will be truncated. In this case, if the file
	* offset as returned by the {@code getFilePointer} method is greater
	* than {@code newLength} then after this method returns the offset
	* will be equal to {@code newLength}.
	*
	* <p> If the present length of the file as returned by the
	* {@code length} method is smaller than the {@code newLength}
	* argument then the file will be extended. In this case, the contents of
	* the extended portion of the file are not defined.
	*
	* @param newLength The desired length of the file
	* @exception IOException If an I/O error occurs
	* @since 1.2
	*/
	public native void setLength(long newLength) throws IOException;

	/**
	* Closes this random access file stream and releases any system
	* resources associated with the stream. A closed random access
	* file cannot perform input or output operations and cannot be
	* reopened.
	*
	* <p> If this file 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 {
	synchronized (closeLock) {
	if (closed) {
	return;
	}
	closed = true;
	}
	if (channel != null) {
	channel.close();
	}

	fd.closeAll(new Closeable() {
	public void close() throws IOException {
	close0();
	}
	});
	}

	//
	// Some "reading/writing Java data types" methods stolen from
	// DataInputStream and DataOutputStream.
	//

	/**
	* Reads a {@code boolean} from this file. This method reads a
	* single byte from the file, starting at the current file pointer.
	* A value of {@code 0} represents
	* {@code false}. Any other value represents {@code true}.
	* This method blocks until the byte is read, the end of the stream
	* is detected, or an exception is thrown.
	*
	* @return the {@code boolean} value read.
	* @exception EOFException if this file has reached the end.
	* @exception IOException if an I/O error occurs.
	*/
	public final boolean readBoolean() throws IOException {
	int ch = this.read();
	if (ch < 0)
	throw new EOFException();
	return (ch != 0);
	}

	/**
	* Reads a signed eight-bit value from this file. This method reads a
	* byte from the file, starting from the current file pointer.
	* If the byte read is {@code b}, where
	* <code>0 <= b <= 255</code>,
	* then the result is:
	* <blockquote><pre>
	* (byte)(b)
	* </pre></blockquote>
	* <p>
	* This method blocks until the byte is read, the end of the stream
	* is detected, or an exception is thrown.
	*
	* @return the next byte of this file as a signed eight-bit
	* {@code byte}.
	* @exception EOFException if this file has reached the end.
	* @exception IOException if an I/O error occurs.
	*/
	public final byte readByte() throws IOException {
	int ch = this.read();
	if (ch < 0)
	throw new EOFException();
	return (byte)(ch);
	}

	/**
	* Reads an unsigned eight-bit number from this file. This method reads
	* a byte from this file, starting at the current file pointer,
	* and returns that byte.
	* <p>
	* This method blocks until the byte is read, the end of the stream
	* is detected, or an exception is thrown.
	*
	* @return the next byte of this file, interpreted as an unsigned
	* eight-bit number.
	* @exception EOFException if this file has reached the end.
	* @exception IOException if an I/O error occurs.
	*/
	public final int readUnsignedByte() throws IOException {
	int ch = this.read();
	if (ch < 0)
	throw new EOFException();
	return ch;
	}

	/**
	* Reads a signed 16-bit number from this file. The method reads two
	* bytes from this file, starting at the current file pointer.
	* If the two bytes read, in order, are
	* {@code b1} and {@code b2}, where each of the two values is
	* between {@code 0} and {@code 255}, inclusive, then the
	* result is equal to:
	* <blockquote><pre>
	* (short)((b1 << 8) \| b2)
	* </pre></blockquote>
	* <p>
	* This method blocks until the two bytes are read, the end of the
	* stream is detected, or an exception is thrown.
	*
	* @return the next two bytes of this file, interpreted as a signed
	* 16-bit number.
	* @exception EOFException if this file reaches the end before reading
	* two bytes.
	* @exception IOException if an I/O error occurs.
	*/
	public final short readShort() throws IOException {
	int ch1 = this.read();
	int ch2 = this.read();
	if ((ch1 \| ch2) < 0)
	throw new EOFException();
	return (short)((ch1 << 8) + (ch2 << 0));
	}

	/**
	* Reads an unsigned 16-bit number from this file. This method reads
	* two bytes from the file, starting at the current file pointer.
	* If the bytes read, in order, are
	* {@code b1} and {@code b2}, where
	* <code>0 <= b1, b2 <= 255</code>,
	* then the result is equal to:
	* <blockquote><pre>
	* (b1 << 8) \| b2
	* </pre></blockquote>
	* <p>
	* This method blocks until the two bytes are read, the end of the
	* stream is detected, or an exception is thrown.
	*
	* @return the next two bytes of this file, interpreted as an unsigned
	* 16-bit integer.
	* @exception EOFException if this file reaches the end before reading
	* two bytes.
	* @exception IOException if an I/O error occurs.
	*/
	public final int readUnsignedShort() throws IOException {
	int ch1 = this.read();
	int ch2 = this.read();
	if ((ch1 \| ch2) < 0)
	throw new EOFException();
	return (ch1 << 8) + (ch2 << 0);
	}

	/**
	* Reads a character from this file. This method reads two
	* bytes from the file, starting at the current file pointer.
	* If the bytes read, in order, are
	* {@code b1} and {@code b2}, where
	* <code>0 <= b1, b2 <= 255</code>,
	* then the result is equal to:
	* <blockquote><pre>
	* (char)((b1 << 8) \| b2)
	* </pre></blockquote>
	* <p>
	* This method blocks until the two bytes are read, the end of the
	* stream is detected, or an exception is thrown.
	*
	* @return the next two bytes of this file, interpreted as a
	* {@code char}.
	* @exception EOFException if this file reaches the end before reading
	* two bytes.
	* @exception IOException if an I/O error occurs.
	*/
	public final char readChar() throws IOException {
	int ch1 = this.read();
	int ch2 = this.read();
	if ((ch1 \| ch2) < 0)
	throw new EOFException();
	return (char)((ch1 << 8) + (ch2 << 0));
	}

	/**
	* Reads a signed 32-bit integer from this file. This method reads 4
	* bytes from the file, starting at the current file pointer.
	* If the bytes read, in order, are {@code b1},
	* {@code b2}, {@code b3}, and {@code b4}, where
	* <code>0 <= b1, b2, b3, b4 <= 255</code>,
	* then the result is equal to:
	* <blockquote><pre>
	* (b1 << 24) \| (b2 << 16) + (b3 << 8) + b4
	* </pre></blockquote>
	* <p>
	* This method blocks until the four bytes are read, the end of the
	* stream is detected, or an exception is thrown.
	*
	* @return the next four bytes of this file, interpreted as an
	* {@code int}.
	* @exception EOFException if this file reaches the end before reading
	* four bytes.
	* @exception IOException if an I/O error occurs.
	*/
	public final int readInt() throws IOException {
	int ch1 = this.read();
	int ch2 = this.read();
	int ch3 = this.read();
	int ch4 = this.read();
	if ((ch1 \| ch2 \| ch3 \| ch4) < 0)
	throw new EOFException();
	return ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + (ch4 << 0));
	}

	/**
	* Reads a signed 64-bit integer from this file. This method reads eight
	* bytes from the file, starting at the current file pointer.
	* If the bytes read, in order, are
	* {@code b1}, {@code b2}, {@code b3},
	* {@code b4}, {@code b5}, {@code b6},
	* {@code b7}, and {@code b8,} where:
	* <blockquote><pre>
	* 0 <= b1, b2, b3, b4, b5, b6, b7, b8 <=255,
	* </pre></blockquote>
	* <p>
	* then the result is equal to:
	* <blockquote><pre>
	* ((long)b1 << 56) + ((long)b2 << 48)
	* + ((long)b3 << 40) + ((long)b4 << 32)
	* + ((long)b5 << 24) + ((long)b6 << 16)
	* + ((long)b7 << 8) + b8
	* </pre></blockquote>
	* <p>
	* This method blocks until the eight bytes are read, the end of the
	* stream is detected, or an exception is thrown.
	*
	* @return the next eight bytes of this file, interpreted as a
	* {@code long}.
	* @exception EOFException if this file reaches the end before reading
	* eight bytes.
	* @exception IOException if an I/O error occurs.
	*/
	public final long readLong() throws IOException {
	return ((long)(readInt()) << 32) + (readInt() & 0xFFFFFFFFL);
	}

	/**
	* Reads a {@code float} from this file. This method reads an
	* {@code int} value, starting at the current file pointer,
	* as if by the {@code readInt} method
	* and then converts that {@code int} to a {@code float}
	* using the {@code intBitsToFloat} method in class
	* {@code Float}.
	* <p>
	* This method blocks until the four bytes are read, the end of the
	* stream is detected, or an exception is thrown.
	*
	* @return the next four bytes of this file, interpreted as a
	* {@code float}.
	* @exception EOFException if this file reaches the end before reading
	* four bytes.
	* @exception IOException if an I/O error occurs.
	* @see java.io.RandomAccessFile#readInt()
	* @see java.lang.Float#intBitsToFloat(int)
	*/
	public final float readFloat() throws IOException {
	return Float.intBitsToFloat(readInt());
	}

	/**
	* Reads a {@code double} from this file. This method reads a
	* {@code long} value, starting at the current file pointer,
	* as if by the {@code readLong} method
	* and then converts that {@code long} to a {@code double}
	* using the {@code longBitsToDouble} method in
	* class {@code Double}.
	* <p>
	* This method blocks until the eight bytes are read, the end of the
	* stream is detected, or an exception is thrown.
	*
	* @return the next eight bytes of this file, interpreted as a
	* {@code double}.
	* @exception EOFException if this file reaches the end before reading
	* eight bytes.
	* @exception IOException if an I/O error occurs.
	* @see java.io.RandomAccessFile#readLong()
	* @see java.lang.Double#longBitsToDouble(long)
	*/
	public final double readDouble() throws IOException {
	return Double.longBitsToDouble(readLong());
	}

	/**
	* Reads the next line of text from this file. This method successively
	* reads bytes from the file, starting at the current file pointer,
	* until it reaches a line terminator or the end
	* of the file. Each byte is converted into a character by taking the
	* byte's value for the lower eight bits of the character and setting the
	* high eight bits of the character to zero. This method does not,
	* therefore, support the full Unicode character set.
	*
	* <p> A line of text is terminated by a carriage-return character
	* ({@code '\u005Cr'}), a newline character ({@code '\u005Cn'}), a
	* carriage-return character immediately followed by a newline character,
	* or the end of the file. Line-terminating characters are discarded and
	* are not included as part of the string returned.
	*
	* <p> This method blocks until a newline character is read, a carriage
	* return and the byte following it are read (to see if it is a newline),
	* the end of the file is reached, or an exception is thrown.
	*
	* @return the next line of text from this file, or null if end
	* of file is encountered before even one byte is read.
	* @exception IOException if an I/O error occurs.
	*/

	public final String readLine() throws IOException {
	StringBuffer input = new StringBuffer();
	int c = -1;
	boolean eol = false;

	while (!eol) {
	switch (c = read()) {
	case -1:
	case '\n':
	eol = true;
	break;
	case '\r':
	eol = true;
	long cur = getFilePointer();
	if ((read()) != '\n') {
	seek(cur);
	}
	break;
	default:
	input.append((char)c);
	break;
	}
	}

	if ((c == -1) && (input.length() == 0)) {
	return null;
	}
	return input.toString();
	}

	/**
	* Reads in a string from this file. The string has been encoded
	* using a
	* <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
	* format.
	* <p>
	* The first two bytes are read, starting from the current file
	* pointer, as if by
	* {@code readUnsignedShort}. This value gives the number of
	* following bytes that are in the encoded string, not
	* the length of the resulting string. The following bytes are then
	* interpreted as bytes encoding characters in the modified UTF-8 format
	* and are converted into characters.
	* <p>
	* This method blocks until all the bytes are read, the end of the
	* stream is detected, or an exception is thrown.
	*
	* @return a Unicode string.
	* @exception EOFException if this file reaches the end before
	* reading all the bytes.
	* @exception IOException if an I/O error occurs.
	* @exception UTFDataFormatException if the bytes do not represent
	* valid modified UTF-8 encoding of a Unicode string.
	* @see java.io.RandomAccessFile#readUnsignedShort()
	*/
	public final String readUTF() throws IOException {
	return DataInputStream.readUTF(this);
	}

	/**
	* Writes a {@code boolean} to the file as a one-byte value. The
	* value {@code true} is written out as the value
	* {@code (byte)1}; the value {@code false} is written out
	* as the value {@code (byte)0}. The write starts at
	* the current position of the file pointer.
	*
	* @param v a {@code boolean} value to be written.
	* @exception IOException if an I/O error occurs.
	*/
	public final void writeBoolean(boolean v) throws IOException {
	write(v ? 1 : 0);
	//written++;
	}

	/**
	* Writes a {@code byte} to the file as a one-byte value. The
	* write starts at the current position of the file pointer.
	*
	* @param v a {@code byte} value to be written.
	* @exception IOException if an I/O error occurs.
	*/
	public final void writeByte(int v) throws IOException {
	write(v);
	//written++;
	}

	/**
	* Writes a {@code short} to the file as two bytes, high byte first.
	* The write starts at the current position of the file pointer.
	*
	* @param v a {@code short} to be written.
	* @exception IOException if an I/O error occurs.
	*/
	public final void writeShort(int v) throws IOException {
	write((v >>> 8) & 0xFF);
	write((v >>> 0) & 0xFF);
	//written += 2;
	}

	/**
	* Writes a {@code char} to the file as a two-byte value, high
	* byte first. The write starts at the current position of the
	* file pointer.
	*
	* @param v a {@code char} value to be written.
	* @exception IOException if an I/O error occurs.
	*/
	public final void writeChar(int v) throws IOException {
	write((v >>> 8) & 0xFF);
	write((v >>> 0) & 0xFF);
	//written += 2;
	}

	/**
	* Writes an {@code int} to the file as four bytes, high byte first.
	* The write starts at the current position of the file pointer.
	*
	* @param v an {@code int} to be written.
	* @exception IOException if an I/O error occurs.
	*/
	public final void writeInt(int v) throws IOException {
	write((v >>> 24) & 0xFF);
	write((v >>> 16) & 0xFF);
	write((v >>> 8) & 0xFF);
	write((v >>> 0) & 0xFF);
	//written += 4;
	}

	/**
	* Writes a {@code long} to the file as eight bytes, high byte first.
	* The write starts at the current position of the file pointer.
	*
	* @param v a {@code long} to be written.
	* @exception IOException if an I/O error occurs.
	*/
	public final void writeLong(long v) throws IOException {
	write((int)(v >>> 56) & 0xFF);
	write((int)(v >>> 48) & 0xFF);
	write((int)(v >>> 40) & 0xFF);
	write((int)(v >>> 32) & 0xFF);
	write((int)(v >>> 24) & 0xFF);
	write((int)(v >>> 16) & 0xFF);
	write((int)(v >>> 8) & 0xFF);
	write((int)(v >>> 0) & 0xFF);
	//written += 8;
	}

	/**
	* Converts the float argument to an {@code int} using the
	* {@code floatToIntBits} method in class {@code Float},
	* and then writes that {@code int} value to the file as a
	* four-byte quantity, high byte first. The write starts at the
	* current position of the file pointer.
	*
	* @param v a {@code float} value to be written.
	* @exception IOException if an I/O error occurs.
	* @see java.lang.Float#floatToIntBits(float)
	*/
	public final void writeFloat(float v) throws IOException {
	writeInt(Float.floatToIntBits(v));
	}

	/**
	* Converts the double argument to a {@code long} using the
	* {@code doubleToLongBits} method in class {@code Double},
	* and then writes that {@code long} value to the file as an
	* eight-byte quantity, high byte first. The write starts at the current
	* position of the file pointer.
	*
	* @param v a {@code double} value to be written.
	* @exception IOException if an I/O error occurs.
	* @see java.lang.Double#doubleToLongBits(double)
	*/
	public final void writeDouble(double v) throws IOException {
	writeLong(Double.doubleToLongBits(v));
	}

	/**
	* Writes the string to the file as a sequence of bytes. Each
	* character in the string is written out, in sequence, by discarding
	* its high eight bits. The write starts at the current position of
	* the file pointer.
	*
	* @param s a string of bytes to be written.
	* @exception IOException if an I/O error occurs.
	*/
	@SuppressWarnings("deprecation")
	public final void writeBytes(String s) throws IOException {
	int len = s.length();
	byte[] b = new byte[len];
	s.getBytes(0, len, b, 0);
	writeBytes(b, 0, len);
	}

	/**
	* Writes a string to the file as a sequence of characters. Each
	* character is written to the data output stream as if by the
	* {@code writeChar} method. The write starts at the current
	* position of the file pointer.
	*
	* @param s a {@code String} value to be written.
	* @exception IOException if an I/O error occurs.
	* @see java.io.RandomAccessFile#writeChar(int)
	*/
	public final void writeChars(String s) throws IOException {
	int clen = s.length();
	int blen = 2*clen;
	byte[] b = new byte[blen];
	char[] c = new char[clen];
	s.getChars(0, clen, c, 0);
	for (int i = 0, j = 0; i < clen; i++) {
	b[j++] = (byte)(c[i] >>> 8);
	b[j++] = (byte)(c[i] >>> 0);
	}
	writeBytes(b, 0, blen);
	}

	/**
	* Writes a string to the file using
	* <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
	* encoding in a machine-independent manner.
	* <p>
	* First, two bytes are written to the file, starting at the
	* current file pointer, as if by the
	* {@code writeShort} method giving the number of bytes to
	* follow. This value is the number of bytes actually written out,
	* not the length of the string. Following the length, each character
	* of the string is output, in sequence, using the modified UTF-8 encoding
	* for each character.
	*
	* @param str a string to be written.
	* @exception IOException if an I/O error occurs.
	*/
	public final void writeUTF(String str) throws IOException {
	DataOutputStream.writeUTF(str, this);
	}

	private static native void initIDs();

	private native void close0() throws IOException;

	static {
	initIDs();
	}
	}

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