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Diffstat (limited to 'libjava/java/io/DataInputStream.java')
| -rw-r--r-- | libjava/java/io/DataInputStream.java | 739 |
1 files changed, 0 insertions, 739 deletions
diff --git a/libjava/java/io/DataInputStream.java b/libjava/java/io/DataInputStream.java deleted file mode 100644 index da60a8e8c68..00000000000 --- a/libjava/java/io/DataInputStream.java +++ /dev/null @@ -1,739 +0,0 @@ -/* DataInputStream.java -- FilteredInputStream that implements DataInput - Copyright (C) 1998, 1999, 2000, 2001, 2003, 2005 Free Software Foundation - -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; - -/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3 - * "The Java Language Specification", ISBN 0-201-63451-1 - * plus online API docs for JDK 1.2 beta from http://www.javasoft.com. - * Status: Believed complete and correct. - */ - -/** - * This subclass of <code>FilteredInputStream</code> implements the - * <code>DataInput</code> interface that provides method for reading primitive - * Java data types from a stream. - * - * @see DataInput - * - * @author Warren Levy (warrenl@cygnus.com) - * @author Aaron M. Renn (arenn@urbanophile.com) - * @date October 20, 1998. - */ -public class DataInputStream extends FilterInputStream implements DataInput -{ - // Byte buffer, used to make primitive read calls more efficient. - byte[] buf = new byte [8]; - - /** - * This constructor initializes a new <code>DataInputStream</code> - * to read from the specified subordinate stream. - * - * @param in The subordinate <code>InputStream</code> to read from - */ - public DataInputStream (InputStream in) - { - super (in); - } - - /** - * This method reads bytes from the underlying stream into the specified - * byte array buffer. It will attempt to fill the buffer completely, but - * may return a short count if there is insufficient data remaining to be - * read to fill the buffer. - * - * @param b The buffer into which bytes will be read. - * - * @return The actual number of bytes read, or -1 if end of stream reached - * before reading any bytes. - * - * @exception IOException If an error occurs. - */ - public final int read (byte[] b) throws IOException - { - return in.read (b, 0, b.length); - } - - /** - * This method reads bytes from the underlying stream into the specified - * byte array buffer. It will attempt to read <code>len</code> bytes and - * will start storing them at position <code>off</code> into the buffer. - * This method can return a short count if there is insufficient data - * remaining to be read to complete the desired read length. - * - * @param b The buffer into which bytes will be read. - * @param off The offset into the buffer 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 stream reached - * before reading any bytes. - * - * @exception IOException If an error occurs. - */ - public final int read (byte[] b, int off, int len) throws IOException - { - return in.read (b, off, 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 - * - * @see DataOutput#writeBoolean - */ - public final boolean readBoolean () throws IOException - { - return convertToBoolean (in.read ()); - } - - /** - * 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#writeByte - */ - public final byte readByte () throws IOException - { - return convertToByte (in.read ()); - } - - /** - * 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#writeChar - */ - public final char readChar () throws IOException - { - readFully (buf, 0, 2); - return convertToChar (buf); - } - - /** - * This method reads a Java double value from an input stream. It operates - * by first reading a <code>long</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 DataOutput#writeDouble - * @see java.lang.Double#longBitsToDouble - */ - public final double readDouble () throws IOException - { - return Double.longBitsToDouble (readLong ()); - } - - /** - * 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 DataOutput#writeFloat - * @see java.lang.Float#intBitsToFloat - */ - public final float readFloat () throws IOException - { - return Float.intBitsToFloat (readInt ()); - } - - /** - * 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. Note also that zero length buffers are permitted. - * In this case, the method will return immediately without reading any - * bytes from the stream. - * - * @param b 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[] b) throws IOException - { - readFully (b, 0, b.length); - } - - /** - * 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. Note also that zero length - * buffers are permitted. In this case, the method will return immediately - * without reading any bytes from the stream. - * - * @param buf The buffer into which to read the data - * @param offset The offset into the buffer to start storing data - * @param len 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[] buf, int offset, int len) throws IOException - { - if (len < 0) - throw new IndexOutOfBoundsException("Negative length: " + len); - - while (len > 0) - { - // in.read will block until some data is available. - int numread = in.read (buf, offset, len); - if (numread < 0) - throw new EOFException (); - len -= numread; - offset += numread; - } - } - - /** - * 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 -2147483648 to 2147483647. - * <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#writeInt - */ - public final int readInt () throws IOException - { - readFully (buf, 0, 4); - return convertToInt (buf); - } - - /** - * 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 0 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 - * - * @deprecated - */ - public final String readLine() throws IOException - { - StringBuffer strb = new StringBuffer(); - - while (true) - { - int c = in.read(); - if (c == -1) // got an EOF - return strb.length() > 0 ? strb.toString() : null; - if (c == '\r') - { - int next_c = in.read(); - if (next_c != '\n' && next_c != -1) - { - if (! (in instanceof PushbackInputStream)) - in = new PushbackInputStream(in); - ((PushbackInputStream) in).unread(next_c); - } - break; - } - if (c == '\n') - break; - strb.append((char) c); - } - - return strb.length() > 0 ? strb.toString() : ""; - } - - /** - * This method reads a Java <code>long</code> 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)(((byte1 & 0xFF) << 56) + ((byte2 & 0xFF) << 48) + - * ((byte3 & 0xFF) << 40) + ((byte4 & 0xFF) << 32) + - * ((byte5 & 0xFF) << 24) + ((byte6 & 0xFF) << 16) + - * ((byte7 & 0xFF) << 8) + (byte8 & 0xFF))) - * </code> - * <p> - * The value returned is in the range of -9223372036854775808 to - * 9223372036854775807. - * <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#writeLong - */ - public final long readLong () throws IOException - { - readFully (buf, 0, 8); - return convertToLong (buf); - } - - /** - * 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#writeShort - */ - public final short readShort () throws IOException - { - readFully (buf, 0, 2); - return convertToShort (buf); - } - - /** - * 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#writeByte - */ - public final int readUnsignedByte () throws IOException - { - return convertToUnsignedByte (in.read ()); - } - - /** - * 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 - * - * @see DataOutput#writeShort - */ - public final int readUnsignedShort () throws IOException - { - readFully (buf, 0, 2); - return convertToUnsignedShort (buf); - } - - /** - * 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 110 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 1110 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 10 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#writeUTF - */ - public final String readUTF () throws IOException - { - return readUTF (this); - } - - /** - * This method reads a String encoded in UTF-8 format from the - * specified <code>DataInput</code> source. - * - * @param in The <code>DataInput</code> source to read from - * - * @return The String read from the source - * - * @exception IOException If an error occurs - * - * @see DataInput#readUTF - */ - public static final String readUTF(DataInput in) throws IOException - { - final int UTFlen = in.readUnsignedShort (); - byte[] buf = new byte [UTFlen]; - - // This blocks until the entire string is available rather than - // doing partial processing on the bytes that are available and then - // blocking. An advantage of the latter is that Exceptions - // could be thrown earlier. The former is a bit cleaner. - in.readFully (buf, 0, UTFlen); - - return convertFromUTF (buf); - } - - /** - * This method attempts to skip and discard the specified number of bytes - * in the input stream. It may actually skip fewer bytes than requested. - * This method will not skip any bytes if passed a negative number of bytes - * to skip. - * - * @param n The requested number of bytes to skip. - * - * @return The requested number of bytes to skip. - * - * @exception IOException If an error occurs. - * @specnote The JDK docs claim that this returns the number of bytes - * actually skipped. The JCL claims that this method can throw an - * EOFException. Neither of these appear to be true in the JDK 1.3's - * implementation. This tries to implement the actual JDK behaviour. - */ - public final int skipBytes (int n) throws IOException - { - if (n <= 0) - return 0; - try - { - return (int) in.skip (n); - } - catch (EOFException x) - { - // do nothing. - } - return n; - } - - static boolean convertToBoolean (int b) throws EOFException - { - if (b < 0) - throw new EOFException (); - - return (b != 0); - } - - static byte convertToByte (int i) throws EOFException - { - if (i < 0) - throw new EOFException (); - - return (byte) i; - } - - static int convertToUnsignedByte (int i) throws EOFException - { - if (i < 0) - throw new EOFException (); - - return (i & 0xFF); - } - - static char convertToChar (byte[] buf) - { - return (char) ((buf [0] << 8) - | (buf [1] & 0xff)); - } - - static short convertToShort (byte[] buf) - { - return (short) ((buf [0] << 8) - | (buf [1] & 0xff)); - } - - static int convertToUnsignedShort (byte[] buf) - { - return (((buf [0] & 0xff) << 8) - | (buf [1] & 0xff)); - } - - static int convertToInt (byte[] buf) - { - return (((buf [0] & 0xff) << 24) - | ((buf [1] & 0xff) << 16) - | ((buf [2] & 0xff) << 8) - | (buf [3] & 0xff)); - } - - static long convertToLong (byte[] buf) - { - return (((long)(buf [0] & 0xff) << 56) | - ((long)(buf [1] & 0xff) << 48) | - ((long)(buf [2] & 0xff) << 40) | - ((long)(buf [3] & 0xff) << 32) | - ((long)(buf [4] & 0xff) << 24) | - ((long)(buf [5] & 0xff) << 16) | - ((long)(buf [6] & 0xff) << 8) | - ((long)(buf [7] & 0xff))); - } - - // FIXME: This method should be re-thought. I suspect we have multiple - // UTF-8 decoders floating around. We should use the standard charset - // converters, maybe and adding a direct call into one of the new - // NIO converters for a super-fast UTF8 decode. - static String convertFromUTF (byte[] buf) - throws EOFException, UTFDataFormatException - { - // Give StringBuffer an initial estimated size to avoid - // enlarge buffer frequently - StringBuffer strbuf = new StringBuffer (buf.length / 2 + 2); - - for (int i = 0; i < buf.length; ) - { - if ((buf [i] & 0x80) == 0) // bit pattern 0xxxxxxx - strbuf.append ((char) (buf [i++] & 0xFF)); - else if ((buf [i] & 0xE0) == 0xC0) // bit pattern 110xxxxx - { - if (i + 1 >= buf.length - || (buf [i + 1] & 0xC0) != 0x80) - throw new UTFDataFormatException (); - - strbuf.append((char) (((buf [i++] & 0x1F) << 6) - | (buf [i++] & 0x3F))); - } - else if ((buf [i] & 0xF0) == 0xE0) // bit pattern 1110xxxx - { - if (i + 2 >= buf.length - || (buf [i + 1] & 0xC0) != 0x80 - || (buf [i + 2] & 0xC0) != 0x80) - throw new UTFDataFormatException (); - - strbuf.append ((char) (((buf [i++] & 0x0F) << 12) - | ((buf [i++] & 0x3F) << 6) - | (buf [i++] & 0x3F))); - } - else // must be ((buf [i] & 0xF0) == 0xF0 || (buf [i] & 0xC0) == 0x80) - throw new UTFDataFormatException (); // bit patterns 1111xxxx or - // 10xxxxxx - } - - return strbuf.toString (); - } -} |