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Diffstat (limited to 'libjava/java/io/RandomAccessFile.java')
| -rw-r--r-- | libjava/java/io/RandomAccessFile.java | 1036 |
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diff --git a/libjava/java/io/RandomAccessFile.java b/libjava/java/io/RandomAccessFile.java deleted file mode 100644 index d719a1e..0000000 --- a/libjava/java/io/RandomAccessFile.java +++ /dev/null @@ -1,1036 +0,0 @@ -/* RandomAccessFile.java -- Class supporting random file I/O - Copyright (C) 1998, 1999, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. - -This file is part of GNU Classpath. - -GNU Classpath is free software; you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation; either version 2, or (at your option) -any later version. - -GNU Classpath 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 for more details. - -You should have received a copy of the GNU General Public License -along with GNU Classpath; see the file COPYING. If not, write to the -Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA -02110-1301 USA. - -Linking this library statically or dynamically with other modules is -making a combined work based on this library. Thus, the terms and -conditions of the GNU General Public License cover the whole -combination. - -As a special exception, the copyright holders of this library give you -permission to link this library with independent modules to produce an -executable, regardless of the license terms of these independent -modules, and to copy and distribute the resulting executable under -terms of your choice, provided that you also meet, for each linked -independent module, the terms and conditions of the license of that -module. An independent module is a module which is not derived from -or based on this library. If you modify this library, you may extend -this exception to your version of the library, but you are not -obligated to do so. If you do not wish to do so, delete this -exception statement from your version. */ - - -package java.io; - -import gnu.java.nio.channels.FileChannelImpl; - -import java.nio.channels.FileChannel; - -/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3 - * "The Java Language Specification", ISBN 0-201-63451-1 - * Status: Believe complete and correct to 1.1. - */ - -/** - * This class allows reading and writing of files at random locations. - * Most Java I/O classes are either pure sequential input or output. This - * class fulfills the need to be able to read the bytes of a file in an - * arbitrary order. In addition, this class implements the - * <code>DataInput</code> and <code>DataOutput</code> interfaces to allow - * the reading and writing of Java primitives. - * - * @author Aaron M. Renn (arenn@urbanophile.com) - * @author Tom Tromey (tromey@cygnus.com) - */ -public class RandomAccessFile implements DataOutput, DataInput, Closeable -{ - - // The underlying file. - private FileChannelImpl ch; - private FileDescriptor fd; - // The corresponding input and output streams. - private DataOutputStream out; - private DataInputStream in; - - - /** - * This method initializes a new instance of <code>RandomAccessFile</code> - * to read from the specified <code>File</code> object with the specified - * access mode. The access mode is either "r" for read only access or "rw" - * for read-write access. - * <p> - * Note that a <code>SecurityManager</code> check is made prior to - * opening the file to determine whether or not this file is allowed to - * be read or written. - * - * @param file The <code>File</code> object to read and/or write. - * @param mode "r" for read only or "rw" for read-write access to the file - * - * @exception IllegalArgumentException If <code>mode</code> has an - * illegal value - * @exception SecurityException If the requested access to the file - * is not allowed - * @exception FileNotFoundException If the file is a directory, or - * any other error occurs - */ - public RandomAccessFile (File file, String mode) - throws FileNotFoundException - { - int fdmode; - if (mode.equals("r")) - fdmode = FileChannelImpl.READ; - else if (mode.equals("rw")) - fdmode = FileChannelImpl.READ | FileChannelImpl.WRITE; - else if (mode.equals("rws")) - { - fdmode = (FileChannelImpl.READ | FileChannelImpl.WRITE - | FileChannelImpl.SYNC); - } - else if (mode.equals("rwd")) - { - fdmode = (FileChannelImpl.READ | FileChannelImpl.WRITE - | FileChannelImpl.DSYNC); - } - else - throw new IllegalArgumentException ("invalid mode: " + mode); - - final String fileName = file.getPath(); - - // The obligatory SecurityManager stuff - SecurityManager s = System.getSecurityManager(); - if (s != null) - { - s.checkRead(fileName); - - if ((fdmode & FileChannelImpl.WRITE) != 0) - s.checkWrite(fileName); - } - - ch = FileChannelImpl.create(file, fdmode); - fd = new FileDescriptor(ch); - if ((fdmode & FileChannelImpl.WRITE) != 0) - out = new DataOutputStream (new FileOutputStream (fd)); - else - out = null; - in = new DataInputStream (new FileInputStream (fd)); - } - - /** - * This method initializes a new instance of <code>RandomAccessFile</code> - * to read from the specified file name with the specified access mode. - * The access mode is either "r" for read only access, "rw" for read - * write access, "rws" for synchronized read/write access of both - * content and metadata, or "rwd" for read/write access - * where only content is required to be synchronous. - * <p> - * Note that a <code>SecurityManager</code> check is made prior to - * opening the file to determine whether or not this file is allowed to - * be read or written. - * - * @param fileName The name of the file to read and/or write - * @param mode "r", "rw", "rws", or "rwd" - * - * @exception IllegalArgumentException If <code>mode</code> has an - * illegal value - * @exception SecurityException If the requested access to the file - * is not allowed - * @exception FileNotFoundException If the file is a directory or - * any other error occurs - */ - public RandomAccessFile (String fileName, String mode) - throws FileNotFoundException - { - this (new File(fileName), mode); - } - - /** - * This method closes the file and frees up all file related system - * resources. Since most operating systems put a limit on how many files - * may be opened at any given time, it is a good idea to close all files - * when no longer needed to avoid hitting this limit - */ - public void close () throws IOException - { - ch.close(); - } - - /** - * This method returns a <code>FileDescriptor</code> object that - * represents the native file handle for this file. - * - * @return The <code>FileDescriptor</code> object for this file - * - * @exception IOException If an error occurs - */ - public final FileDescriptor getFD () throws IOException - { - synchronized (this) - { - if (fd == null) - fd = new FileDescriptor (ch); - return fd; - } - } - - /** - * This method returns the current offset in the file at which the next - * read or write will occur - * - * @return The current file position - * - * @exception IOException If an error occurs - */ - public long getFilePointer () throws IOException - { - return ch.position(); - } - - /** - * This method sets the length of the file to the specified length. - * If the currently length of the file is longer than the specified - * length, then the file is truncated to the specified length (the - * file position is set to the end of file in this case). If the - * current length of the file is shorter than the specified length, - * the file is extended with bytes of an undefined value (the file - * position is unchanged in this case). - * <p> - * The file must be open for write access for this operation to succeed. - * - * @param newLen The new length of the file - * - * @exception IOException If an error occurs - */ - public void setLength (long newLen) throws IOException - { - // FIXME: Extending a file should probably be done by one method call. - - // FileChannel.truncate() can only shrink a file. - // To expand it we need to seek forward and write at least one byte. - if (newLen < length()) - ch.truncate (newLen); - else if (newLen > length()) - { - long pos = getFilePointer(); - seek(newLen - 1); - write(0); - seek(pos); - } - } - - /** - * This method returns the length of the file in bytes - * - * @return The length of the file - * - * @exception IOException If an error occurs - */ - public long length () throws IOException - { - return ch.size(); - } - - /** - * This method reads a single byte of data from the file and returns it - * as an integer. - * - * @return The byte read as an int, or -1 if the end of the file was reached. - * - * @exception IOException If an error occurs - */ - public int read () throws IOException - { - return in.read(); - } - - /** - * This method reads bytes from the file into the specified array. The - * bytes are stored starting at the beginning of the array and up to - * <code>buf.length</code> bytes can be read. - * - * @param buffer The buffer to read bytes from the file into - * - * @return The actual number of bytes read or -1 if end of file - * - * @exception IOException If an error occurs - */ - public int read (byte[] buffer) throws IOException - { - return in.read (buffer); - } - - /** - * This methods reads up to <code>len</code> bytes from the file into the - * specified array starting at position <code>offset</code> into the array. - * - * @param buffer The array to read the bytes into - * @param offset The index into the array to start storing bytes - * @param len The requested number of bytes to read - * - * @return The actual number of bytes read, or -1 if end of file - * - * @exception IOException If an error occurs - */ - public int read (byte[] buffer, int offset, int len) throws IOException - { - return in.read (buffer, offset, len); - } - - /** - * This method reads a Java boolean value from an input stream. It does - * so by reading a single byte of data. If that byte is zero, then the - * value returned is <code>false</code> If the byte is non-zero, then - * the value returned is <code>true</code> - * <p> - * This method can read a <code>boolean</code> written by an object - * implementing the - * <code>writeBoolean()</code> method in the <code>DataOutput</code> - * interface. - * - * @return The <code>boolean</code> value read - * - * @exception EOFException If end of file is reached before reading the - * boolean - * @exception IOException If any other error occurs - */ - public final boolean readBoolean () throws IOException - { - return in.readBoolean (); - } - - /** - * This method reads a Java byte value from an input stream. The value - * is in the range of -128 to 127. - * <p> - * This method can read a <code>byte</code> written by an object - * implementing the - * <code>writeByte()</code> method in the <code>DataOutput</code> interface. - * - * @return The <code>byte</code> value read - * - * @exception EOFException If end of file is reached before reading the byte - * @exception IOException If any other error occurs - * - * @see DataOutput - */ - public final byte readByte () throws IOException - { - return in.readByte (); - } - - /** - * This method reads a Java <code>char</code> value from an input stream. - * It operates by reading two bytes from the stream and converting them to - * a single 16-bit Java <code>char</code> The two bytes are stored most - * significant byte first (i.e., "big endian") regardless of the native - * host byte ordering. - * <p> - * As an example, if <code>byte1</code> and <code>byte2</code> represent - * the first - * and second byte read from the stream respectively, they will be - * transformed to a <code>char</code> in the following manner: - * <p> - * <code>(char)(((byte1 & 0xFF) << 8) | (byte2 & 0xFF)</code> - * <p> - * This method can read a <code>char</code> written by an object - * implementing the - * <code>writeChar()</code> method in the <code>DataOutput</code> interface. - * - * @return The <code>char</code> value read - * - * @exception EOFException If end of file is reached before reading the char - * @exception IOException If any other error occurs - * - * @see DataOutput - */ - public final char readChar () throws IOException - { - return in.readChar(); - } - - /** - * This method reads a Java double value from an input stream. It operates - * by first reading a <code>logn</code> value from the stream by calling the - * <code>readLong()</code> method in this interface, then - * converts that <code>long</code> - * to a <code>double</code> using the <code>longBitsToDouble</code> - * method in the class <code>java.lang.Double</code> - * <p> - * This method can read a <code>double</code> written by an object - * implementing the - * <code>writeDouble()</code> method in the <code>DataOutput</code> - * interface. - * - * @return The <code>double</code> value read - * - * @exception EOFException If end of file is reached before reading - * the double - * @exception IOException If any other error occurs - * - * @see java.lang.Double - * @see DataOutput - */ - public final double readDouble () throws IOException - { - return in.readDouble (); - } - - /** - * This method reads a Java float value from an input stream. It operates - * by first reading an <code>int</code> value from the stream by calling the - * <code>readInt()</code> method in this interface, then converts - * that <code>int</code> - * to a <code>float</code> using the <code>intBitsToFloat</code> method in - * the class <code>java.lang.Float</code> - * <p> - * This method can read a <code>float</code> written by an object - * implementing the - * <code>writeFloat()</code> method in the <code>DataOutput</code> interface. - * - * @return The <code>float</code> value read - * - * @exception EOFException If end of file is reached before reading the float - * @exception IOException If any other error occurs - * - * @see java.lang.Float - * @see DataOutput - */ - public final float readFloat () throws IOException - { - return in.readFloat(); - } - - /** - * This method reads raw bytes into the passed array until the array is - * full. Note that this method blocks until the data is available and - * throws an exception if there is not enough data left in the stream to - * fill the buffer - * - * @param buffer The buffer into which to read the data - * - * @exception EOFException If end of file is reached before filling the - * buffer - * @exception IOException If any other error occurs - */ - public final void readFully (byte[] buffer) throws IOException - { - in.readFully(buffer); - } - - /** - * This method reads raw bytes into the passed array <code>buf</code> - * starting - * <code>offset</code> bytes into the buffer. The number of bytes read - * will be - * exactly <code>len</code> Note that this method blocks until the data is - * available and throws an exception if there is not enough data left in - * the stream to read <code>len</code> bytes. - * - * @param buffer The buffer into which to read the data - * @param offset The offset into the buffer to start storing data - * @param count The number of bytes to read into the buffer - * - * @exception EOFException If end of file is reached before filling - * the buffer - * @exception IOException If any other error occurs - */ - public final void readFully (byte[] buffer, int offset, int count) - throws IOException - { - in.readFully (buffer, offset, count); - } - - /** - * This method reads a Java <code>int</code> value from an input stream - * It operates by reading four bytes from the stream and converting them to - * a single Java <code>int</code> The bytes are stored most - * significant byte first (i.e., "big endian") regardless of the native - * host byte ordering. - * <p> - * As an example, if <code>byte1</code> through <code>byte4</code> - * represent the first - * four bytes read from the stream, they will be - * transformed to an <code>int</code> in the following manner: - * <p> - * <code>(int)(((byte1 & 0xFF) << 24) + ((byte2 & 0xFF) << 16) + - * ((byte3 & 0xFF) << 8) + (byte4 & 0xFF)))</code> - * <p> - * The value returned is in the range of 0 to 65535. - * <p> - * This method can read an <code>int</code> written by an object - * implementing the - * <code>writeInt()</code> method in the <code>DataOutput</code> interface. - * - * @return The <code>int</code> value read - * - * @exception EOFException If end of file is reached before reading the int - * @exception IOException If any other error occurs - * - * @see DataOutput - */ - public final int readInt () throws IOException - { - return in.readInt(); - } - - /** - * This method reads the next line of text data from an input stream. - * It operates by reading bytes and converting those bytes to - * <code>char</code> - * values by treating the byte read as the low eight bits of the - * <code>char</code> - * and using <code>0</code> as the high eight bits. Because of this, it does - * not support the full 16-bit Unicode character set. - * <p> - * The reading of bytes ends when either the end of file or a line terminator - * is encountered. The bytes read are then returned as a <code>String</code> - * A line terminator is a byte sequence consisting of either - * <code>\r</code> <code>\n</code> or <code>\r\n</code> These - * termination charaters are - * discarded and are not returned as part of the string. - * <p> - * This method can read data that was written by an object implementing the - * <code>writeLine()</code> method in <code>DataOutput</code> - * - * @return The line read as a <code>String</code> - * - * @exception IOException If an error occurs - * - * @see DataOutput - */ - public final String readLine () throws IOException - { - return in.readLine (); - } - - /** - * This method reads a Java long value from an input stream - * It operates by reading eight bytes from the stream and converting them to - * a single Java <code>long</code> The bytes are stored most - * significant byte first (i.e., "big endian") regardless of the native - * host byte ordering. - * <p> - * As an example, if <code>byte1</code> through <code>byte8</code> - * represent the first - * eight bytes read from the stream, they will be - * transformed to an <code>long</code> in the following manner: - * <p> - * <code> - * (long)((((long)byte1 & 0xFF) << 56) + (((long)byte2 & 0xFF) << 48) + - * (((long)byte3 & 0xFF) << 40) + (((long)byte4 & 0xFF) << 32) + - * (((long)byte5 & 0xFF) << 24) + (((long)byte6 & 0xFF) << 16) + - * (((long)byte7 & 0xFF) << 8) + ((long)byte9 & 0xFF)))</code> - * <p> - * The value returned is in the range of 0 to 65535. - * <p> - * This method can read an <code>long</code> written by an object - * implementing the - * <code>writeLong()</code> method in the <code>DataOutput</code> interface. - * - * @return The <code>long</code> value read - * - * @exception EOFException If end of file is reached before reading the long - * @exception IOException If any other error occurs - * - * @see DataOutput - */ - public final long readLong () throws IOException - { - return in.readLong(); - } - - /** - * This method reads a signed 16-bit value into a Java in from the stream. - * It operates by reading two bytes from the stream and converting them to - * a single 16-bit Java <code>short</code> The two bytes are stored most - * significant byte first (i.e., "big endian") regardless of the native - * host byte ordering. - * <p> - * As an example, if <code>byte1</code> and <code>byte2</code> - * represent the first - * and second byte read from the stream respectively, they will be - * transformed to a <code>short</code> in the following manner: - * <p> - * <code>(short)(((byte1 & 0xFF) << 8) | (byte2 & 0xFF)</code> - * <p> - * The value returned is in the range of -32768 to 32767. - * <p> - * This method can read a <code>short</code> written by an object - * implementing the - * <code>writeShort()</code> method in the <code>DataOutput</code> interface. - * - * @return The <code>short</code> value read - * - * @exception EOFException If end of file is reached before reading the value - * @exception IOException If any other error occurs - * - * @see DataOutput - */ - public final short readShort () throws IOException - { - return in.readShort(); - } - - /** - * This method reads 8 unsigned bits into a Java <code>int</code> value - * from the - * stream. The value returned is in the range of 0 to 255. - * <p> - * This method can read an unsigned byte written by an object implementing - * the <code>writeUnsignedByte()</code> method in the - * <code>DataOutput</code> interface. - * - * @return The unsigned bytes value read as a Java <code>int</code> - * - * @exception EOFException If end of file is reached before reading the value - * @exception IOException If any other error occurs - * - * @see DataOutput - */ - public final int readUnsignedByte () throws IOException - { - return in.readUnsignedByte(); - } - - /** - * This method reads 16 unsigned bits into a Java int value from the stream. - * It operates by reading two bytes from the stream and converting them to - * a single Java <code>int</code> The two bytes are stored most - * significant byte first (i.e., "big endian") regardless of the native - * host byte ordering. - * <p> - * As an example, if <code>byte1</code> and <code>byte2</code> - * represent the first - * and second byte read from the stream respectively, they will be - * transformed to an <code>int</code> in the following manner: - * <p> - * <code>(int)(((byte1 & 0xFF) << 8) + (byte2 & 0xFF))</code> - * <p> - * The value returned is in the range of 0 to 65535. - * <p> - * This method can read an unsigned short written by an object implementing - * the <code>writeUnsignedShort()</code> method in the - * <code>DataOutput</code> interface. - * - * @return The unsigned short value read as a Java <code>int</code> - * - * @exception EOFException If end of file is reached before reading the value - * @exception IOException If any other error occurs - */ - public final int readUnsignedShort () throws IOException - { - return in.readUnsignedShort(); - } - - /** - * This method reads a <code>String</code> from an input stream that - * is encoded in - * a modified UTF-8 format. This format has a leading two byte sequence - * that contains the remaining number of bytes to read. This two byte - * sequence is read using the <code>readUnsignedShort()</code> method of this - * interface. - * <p> - * After the number of remaining bytes have been determined, these bytes - * are read an transformed into <code>char</code> values. - * These <code>char</code> values - * are encoded in the stream using either a one, two, or three byte format. - * The particular format in use can be determined by examining the first - * byte read. - * <p> - * If the first byte has a high order bit of 0 then - * that character consists on only one byte. This character value consists - * of seven bits that are at positions 0 through 6 of the byte. As an - * example, if <code>byte1</code> is the byte read from the stream, it would - * be converted to a <code>char</code> like so: - * <p> - * <code>(char)byte1</code> - * <p> - * If the first byte has <code>110</code> as its high order bits, then the - * character consists of two bytes. The bits that make up the character - * value are in positions 0 through 4 of the first byte and bit positions - * 0 through 5 of the second byte. (The second byte should have - * 10 as its high order bits). These values are in most significant - * byte first (i.e., "big endian") order. - * <p> - * As an example, if <code>byte1</code> and <code>byte2</code> - * are the first two bytes - * read respectively, and the high order bits of them match the patterns - * which indicate a two byte character encoding, then they would be - * converted to a Java <code>char</code> like so: - * <p> - * <code>(char)(((byte1 & 0x1F) << 6) | (byte2 & 0x3F))</code> - * <p> - * If the first byte has a <code>1110</code> as its high order bits, then the - * character consists of three bytes. The bits that make up the character - * value are in positions 0 through 3 of the first byte and bit positions - * 0 through 5 of the other two bytes. (The second and third bytes should - * have <code>10</code> as their high order bits). These values are in most - * significant byte first (i.e., "big endian") order. - * <p> - * As an example, if <code>byte1</code> <code>byte2</code> - * and <code>byte3</code> are the - * three bytes read, and the high order bits of them match the patterns - * which indicate a three byte character encoding, then they would be - * converted to a Java <code>char</code> like so: - * <p> - * <code>(char)(((byte1 & 0x0F) << 12) | ((byte2 & 0x3F) << 6) | - * (byte3 & 0x3F))</code> - * <p> - * Note that all characters are encoded in the method that requires the - * fewest number of bytes with the exception of the character with the - * value of <code>\u0000</code> which is encoded as two bytes. This is - * a modification of the UTF standard used to prevent C language style - * <code>NUL</code> values from appearing in the byte stream. - * <p> - * This method can read data that was written by an object implementing the - * <code>writeUTF()</code> method in <code>DataOutput</code> - * - * @return The <code>String</code> read - * - * @exception EOFException If end of file is reached before reading the - * String - * @exception UTFDataFormatException If the data is not in UTF-8 format - * @exception IOException If any other error occurs - * - * @see DataOutput - */ - public final String readUTF () throws IOException - { - return in.readUTF(); - } - - /** - * This method sets the current file position to the specified offset - * from the beginning of the file. Note that some operating systems will - * allow the file pointer to be set past the current end of the file. - * - * @param pos The offset from the beginning of the file at which to set - * the file pointer - * - * @exception IOException If an error occurs - */ - public void seek (long pos) throws IOException - { - ch.position(pos); - } - - /** - * This method attempts to skip and discard the specified number of bytes - * in the input stream. It may actually skip fewer bytes than requested. - * The actual number of bytes skipped is returned. This method will not - * skip any bytes if passed a negative number of bytes to skip. - * - * @param numBytes The requested number of bytes to skip. - * - * @return The number of bytes actually skipped. - * - * @exception IOException If an error occurs. - */ - public int skipBytes (int numBytes) throws IOException - { - if (numBytes < 0) - throw new IllegalArgumentException ("Can't skip negative bytes: " + - numBytes); - - if (numBytes == 0) - return 0; - - long oldPos = ch.position(); - long newPos = oldPos + numBytes; - long size = ch.size(); - if (newPos > size) - newPos = size; - ch.position(newPos); - return (int) (ch.position() - oldPos); - } - - /** - * This method writes a single byte of data to the file. The file must - * be open for read-write in order for this operation to succeed. - * - * @param oneByte The byte of data to write, passed as an int. - * - * @exception IOException If an error occurs - */ - public void write (int oneByte) throws IOException - { - if (out == null) - throw new IOException("Bad file descriptor"); - - out.write(oneByte); - } - - /** - * This method writes all the bytes in the specified array to the file. - * The file must be open read-write in order for this operation to succeed. - * - * @param buffer The array of bytes to write to the file - */ - public void write (byte[] buffer) throws IOException - { - if (out == null) - throw new IOException("Bad file descriptor"); - - out.write(buffer); - } - - /** - * This method writes <code>len</code> bytes to the file from the specified - * array starting at index <code>offset</code> into the array. - * - * @param buffer The array of bytes to write to the file - * @param offset The index into the array to start writing file - * @param len The number of bytes to write - * - * @exception IOException If an error occurs - */ - public void write (byte[] buffer, int offset, int len) throws IOException - { - if (out == null) - throw new IOException("Bad file descriptor"); - - out.write (buffer, offset, len); - } - - /** - * This method writes a Java <code>boolean</code> to the underlying output - * stream. For a value of <code>true</code>, 1 is written to the stream. - * For a value of <code>false</code>, 0 is written. - * - * @param val The <code>boolean</code> value to write to the stream - * - * @exception IOException If an error occurs - */ - public final void writeBoolean (boolean val) throws IOException - { - if (out == null) - throw new IOException("Bad file descriptor"); - - out.writeBoolean(val); - } - - /** - * This method writes a Java <code>byte</code> value to the underlying - * output stream. - * - * @param val The <code>byte</code> to write to the stream, passed - * as an <code>int</code>. - * - * @exception IOException If an error occurs - */ - public final void writeByte (int val) throws IOException - { - if (out == null) - throw new IOException("Bad file descriptor"); - - out.writeByte(val); - } - - /** - * This method writes a Java <code>short</code> to the stream, high byte - * first. This method requires two bytes to encode the value. - * - * @param val The <code>short</code> value to write to the stream, - * passed as an <code>int</code>. - * - * @exception IOException If an error occurs - */ - public final void writeShort (int val) throws IOException - { - if (out == null) - throw new IOException("Bad file descriptor"); - - out.writeShort(val); - } - - /** - * This method writes a single <code>char</code> value to the stream, - * high byte first. - * - * @param val The <code>char</code> value to write, passed as - * an <code>int</code>. - * - * @exception IOException If an error occurs - */ - public final void writeChar (int val) throws IOException - { - if (out == null) - throw new IOException("Bad file descriptor"); - - out.writeChar(val); - } - - /** - * This method writes a Java <code>int</code> to the stream, high bytes - * first. This method requires four bytes to encode the value. - * - * @param val The <code>int</code> value to write to the stream. - * - * @exception IOException If an error occurs - */ - public final void writeInt (int val) throws IOException - { - if (out == null) - throw new IOException("Bad file descriptor"); - - out.writeInt(val); - } - - /** - * This method writes a Java <code>long</code> to the stream, high bytes - * first. This method requires eight bytes to encode the value. - * - * @param val The <code>long</code> value to write to the stream. - * - * @exception IOException If an error occurs - */ - public final void writeLong (long val) throws IOException - { - if (out == null) - throw new IOException("Bad file descriptor"); - - out.writeLong(val); - } - - /** - * This method writes a Java <code>float</code> value to the stream. This - * value is written by first calling the method - * <code>Float.floatToIntBits</code> - * to retrieve an <code>int</code> representing the floating point number, - * then writing this <code>int</code> value to the stream exactly the same - * as the <code>writeInt()</code> method does. - * - * @param val The floating point number to write to the stream. - * - * @exception IOException If an error occurs - * - * @see #writeInt(int) - */ - public final void writeFloat (float val) throws IOException - { - if (out == null) - throw new IOException("Bad file descriptor"); - - out.writeFloat(val); - } - - /** - * This method writes a Java <code>double</code> value to the stream. This - * value is written by first calling the method - * <code>Double.doubleToLongBits</code> - * to retrieve an <code>long</code> representing the floating point number, - * then writing this <code>long</code> value to the stream exactly the same - * as the <code>writeLong()</code> method does. - * - * @param val The double precision floating point number to write to the - * stream. - * - * @exception IOException If an error occurs - * - * @see #writeLong(long) - */ - public final void writeDouble (double val) throws IOException - { - if (out == null) - throw new IOException("Bad file descriptor"); - - out.writeDouble(val); - } - - /** - * This method writes all the bytes in a <code>String</code> out to the - * stream. One byte is written for each character in the <code>String</code>. - * The high eight bits of each character are discarded. - * - * @param val The <code>String</code> to write to the stream - * - * @exception IOException If an error occurs - */ - public final void writeBytes (String val) throws IOException - { - if (out == null) - throw new IOException("Bad file descriptor"); - - out.writeBytes(val); - } - - /** - * This method writes all the characters in a <code>String</code> to the - * stream. There will be two bytes for each character value. The high - * byte of the character will be written first. - * - * @param val The <code>String</code> to write to the stream. - * - * @exception IOException If an error occurs - */ - public final void writeChars (String val) throws IOException - { - if (out == null) - throw new IOException("Bad file descriptor"); - - out.writeChars(val); - } - - /** - * This method writes a Java <code>String</code> to the stream in a modified - * UTF-8 format. First, two bytes are written to the stream indicating the - * number of bytes to follow. Note that this is the number of bytes in the - * encoded <code>String</code> not the <code>String</code> length. Next - * come the encoded characters. Each character in the <code>String</code> - * is encoded as either one, two or three bytes. For characters in the - * range of <code>\u0001</code> to <code>\u007F</code>, - * one byte is used. The character - * value goes into bits 0-7 and bit eight is 0. For characters in the range - * of <code>\u0080</code> to <code>\u007FF</code>, two - * bytes are used. Bits - * 6-10 of the character value are encoded bits 0-4 of the first byte, with - * the high bytes having a value of "110". Bits 0-5 of the character value - * are stored in bits 0-5 of the second byte, with the high bits set to - * "10". This type of encoding is also done for the null character - * <code>\u0000</code>. This eliminates any C style NUL character values - * in the output. All remaining characters are stored as three bytes. - * Bits 12-15 of the character value are stored in bits 0-3 of the first - * byte. The high bits of the first bytes are set to "1110". Bits 6-11 - * of the character value are stored in bits 0-5 of the second byte. The - * high bits of the second byte are set to "10". And bits 0-5 of the - * character value are stored in bits 0-5 of byte three, with the high bits - * of that byte set to "10". - * - * @param val The <code>String</code> to write to the output in UTF format - * - * @exception IOException If an error occurs - */ - public final void writeUTF (String val) throws IOException - { - if (out == null) - throw new IOException("Bad file descriptor"); - - out.writeUTF(val); - } - - /** - * This method creates a java.nio.channels.FileChannel. - * Nio does not allow one to create a file channel directly. - * A file channel must be created by first creating an instance of - * Input/Output/RandomAccessFile and invoking the getChannel() method on it. - */ - public final synchronized FileChannel getChannel () - { - return ch; - } -} |