| /* DataOutputStream.java -- Writes primitive Java datatypes to streams |
| Copyright (C) 1998, 2001, 2003, 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., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 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 |
| * Status: Complete to version 1.1. |
| */ |
| |
| /** |
| * This class provides a mechanism for writing primitive Java datatypes |
| * to an <code>OutputStream</code> in a portable way. Data written to |
| * a stream using this class can be read back in using the |
| * <code>DataInputStream</code> class on any platform. |
| * |
| * @see DataInputStream |
| * |
| * @author Aaron M. Renn (arenn@urbanophile.com) |
| * @author Tom Tromey (tromey@cygnus.com) |
| */ |
| public class DataOutputStream extends FilterOutputStream implements DataOutput |
| { |
| /** |
| * This is the total number of bytes that have been written to the |
| * stream by this object instance. |
| */ |
| protected int written; |
| |
| /** |
| * This method initializes an instance of <code>DataOutputStream</code> to |
| * write its data to the specified underlying <code>OutputStream</code> |
| * |
| * @param out The subordinate <code>OutputStream</code> to which this |
| * object will write |
| */ |
| public DataOutputStream (OutputStream out) |
| { |
| super (out); |
| written = 0; |
| } |
| |
| /** |
| * This method flushes any unwritten bytes to the underlying stream. |
| * |
| * @exception IOException If an error occurs. |
| */ |
| public void flush () throws IOException |
| { |
| out.flush(); |
| } |
| |
| /** |
| * This method returns the total number of bytes that have been written to |
| * the underlying output stream so far. This is the value of the |
| * <code>written</code> instance variable |
| * |
| * @return The number of bytes written to the stream. |
| */ |
| public final int size () |
| { |
| return written; |
| } |
| |
| /** |
| * This method writes the specified byte (passed as an <code>int</code>) |
| * to the underlying output stream. |
| * |
| * @param value The <code>byte</code> to write, passed as an <code>int</code>. |
| * |
| * @exception IOException If an error occurs. |
| */ |
| public synchronized void write (int value) throws IOException |
| { |
| out.write (value); |
| ++written; |
| } |
| |
| /** |
| * This method writes <code>len</code> bytes from the specified byte array |
| * <code>buf</code> starting at position <code>offset</code> into the |
| * buffer to the underlying output stream. |
| * |
| * @param buf The byte array to write from. |
| * @param offset The index into the byte array to start writing from. |
| * @param len The number of bytes to write. |
| * |
| * @exception IOException If an error occurs. |
| */ |
| public synchronized void write (byte[] buf, int offset, int len) |
| throws IOException |
| { |
| out.write(buf, offset, len); |
| written += len; |
| } |
| |
| /** |
| * This method writes a Java boolean value to an output stream. If |
| * <code>value</code> is <code>true</code>, a byte with the value of |
| * 1 will be written, otherwise a byte with the value of 0 will be |
| * written. |
| * |
| * The value written can be read using the <code>readBoolean</code> |
| * method in <code>DataInput</code>. |
| * |
| * @param value The <code>boolean</code> value to write to the stream |
| * |
| * @exception IOException If an error occurs |
| * |
| * @see DataInput#readBoolean |
| */ |
| public final void writeBoolean (boolean value) throws IOException |
| { |
| write (value ? 1 : 0); |
| } |
| |
| /** |
| * This method writes a Java byte value to an output stream. The |
| * byte to be written will be in the lowest 8 bits of the |
| * <code>int</code> value passed. |
| * |
| * The value written can be read using the <code>readByte</code> or |
| * <code>readUnsignedByte</code> methods in <code>DataInput</code>. |
| * |
| * @param value The <code>byte</code> to write to the stream, passed as |
| * the low eight bits of an <code>int</code>. |
| * |
| * @exception IOException If an error occurs |
| * |
| * @see DataInput#readByte |
| * @see DataInput#readUnsignedByte |
| */ |
| public final void writeByte (int value) throws IOException |
| { |
| write (value & 0xff); |
| } |
| |
| /** |
| * This method writes a Java short value to an output stream. The |
| * char to be written will be in the lowest 16 bits of the <code>int</code> |
| * value passed. These bytes will be written "big endian". That is, |
| * with the high byte written first in the following manner: |
| * <p> |
| * <code>byte0 = (byte)((value & 0xFF00) >> 8);<br> |
| * byte1 = (byte)(value & 0x00FF);</code> |
| * <p> |
| * |
| * The value written can be read using the <code>readShort</code> and |
| * <code>readUnsignedShort</code> methods in <code>DataInput</code>. |
| * |
| * @param value The <code>short</code> value to write to the stream, |
| * passed as an <code>int</code>. |
| * |
| * @exception IOException If an error occurs |
| * |
| * @see DataInput#readShort |
| * @see DataInput#readUnsignedShort |
| */ |
| public final synchronized void writeShort (int value) throws IOException |
| { |
| write ((byte) (0xff & (value >> 8))); |
| write ((byte) (0xff & value)); |
| } |
| |
| /** |
| * This method writes a Java char value to an output stream. The |
| * char to be written will be in the lowest 16 bits of the <code>int</code> |
| * value passed. These bytes will be written "big endian". That is, |
| * with the high byte written first in the following manner: |
| * <p> |
| * <code>byte0 = (byte)((value & 0xFF00) >> 8);<br> |
| * byte1 = (byte)(value & 0x00FF);</code> |
| * <p> |
| * |
| * The value written can be read using the <code>readChar</code> |
| * method in <code>DataInput</code>. |
| * |
| * @param value The <code>char</code> value to write, |
| * passed as an <code>int</code>. |
| * |
| * @exception IOException If an error occurs |
| * |
| * @see DataInput#readChar |
| */ |
| public final synchronized void writeChar (int value) throws IOException |
| { |
| write ((byte) (0xff & (value >> 8))); |
| write ((byte) (0xff & value)); |
| } |
| |
| /** |
| * This method writes a Java int value to an output stream. The 4 bytes |
| * of the passed value will be written "big endian". That is, with |
| * the high byte written first in the following manner: |
| * <p> |
| * <code>byte0 = (byte)((value & 0xFF000000) >> 24);<br> |
| * byte1 = (byte)((value & 0x00FF0000) >> 16);<br> |
| * byte2 = (byte)((value & 0x0000FF00) >> 8);<br> |
| * byte3 = (byte)(value & 0x000000FF);</code> |
| * <p> |
| * |
| * The value written can be read using the <code>readInt</code> |
| * method in <code>DataInput</code>. |
| * |
| * @param value The <code>int</code> value to write to the stream |
| * |
| * @exception IOException If an error occurs |
| * |
| * @see DataInput#readInt |
| */ |
| public final synchronized void writeInt (int value) throws IOException |
| { |
| write ((byte) (0xff & (value >> 24))); |
| write ((byte) (0xff & (value >> 16))); |
| write ((byte) (0xff & (value >> 8))); |
| write ((byte) (0xff & value)); |
| } |
| |
| /** |
| * This method writes a Java long value to an output stream. The 8 bytes |
| * of the passed value will be written "big endian". That is, with |
| * the high byte written first in the following manner: |
| * <p> |
| * <code>byte0 = (byte)((value & 0xFF00000000000000L) >> 56);<br> |
| * byte1 = (byte)((value & 0x00FF000000000000L) >> 48);<br> |
| * byte2 = (byte)((value & 0x0000FF0000000000L) >> 40);<br> |
| * byte3 = (byte)((value & 0x000000FF00000000L) >> 32);<br> |
| * byte4 = (byte)((value & 0x00000000FF000000L) >> 24);<br> |
| * byte5 = (byte)((value & 0x0000000000FF0000L) >> 16);<br> |
| * byte6 = (byte)((value & 0x000000000000FF00L) >> 8);<br> |
| * byte7 = (byte)(value & 0x00000000000000FFL);</code> |
| * <p> |
| * |
| * The value written can be read using the <code>readLong</code> |
| * method in <code>DataInput</code>. |
| * |
| * @param value The <code>long</code> value to write to the stream |
| * |
| * @exception IOException If an error occurs |
| * |
| * @see DataInput#readLong |
| */ |
| public final synchronized void writeLong (long value) throws IOException |
| { |
| write ((byte) (0xff & (value >> 56))); |
| write ((byte) (0xff & (value>> 48))); |
| write ((byte) (0xff & (value>> 40))); |
| write ((byte) (0xff & (value>> 32))); |
| write ((byte) (0xff & (value>> 24))); |
| write ((byte) (0xff & (value>> 16))); |
| write ((byte) (0xff & (value>> 8))); |
| write ((byte) (0xff & value)); |
| } |
| |
| /** |
| * 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. |
| * |
| * The value written can be read using the <code>readFloat</code> |
| * method in <code>DataInput</code>. |
| * |
| * @param value The <code>float</code> value to write to the stream |
| * |
| * @exception IOException If an error occurs |
| * |
| * @see writeInt |
| * @see DataInput#readFloat |
| * @see Float#floatToIntBits |
| */ |
| public final void writeFloat (float value) throws IOException |
| { |
| writeInt (Float.floatToIntBits (value)); |
| } |
| |
| /** |
| * 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. |
| * |
| * The value written can be read using the <code>readDouble</code> |
| * method in <code>DataInput</code>. |
| * |
| * @param value The <code>double</code> value to write to the stream |
| * |
| * @exception IOException If an error occurs |
| * |
| * @see writeLong |
| * @see DataInput#readDouble |
| * @see Double#doubleToLongBits |
| */ |
| public final void writeDouble (double value) throws IOException |
| { |
| writeLong (Double.doubleToLongBits (value)); |
| } |
| |
| /** |
| * 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, thus this |
| * method is inappropriate for completely representing Unicode characters. |
| * |
| * @param value The <code>String</code> to write to the stream |
| * |
| * @exception IOException If an error occurs |
| */ |
| public final void writeBytes (String value) throws IOException |
| { |
| int len = value.length(); |
| for (int i = 0; i < len; ++i) |
| writeByte (value.charAt(i)); |
| } |
| |
| /** |
| * This method writes all the characters of a <code>String</code> to an |
| * output stream as an array of <code>char</code>'s. Each character |
| * is written using the method specified in the <code>writeChar</code> |
| * method. |
| * |
| * @param value The <code>String</code> to write to the stream |
| * |
| * @exception IOException If an error occurs |
| * |
| * @see writeChar |
| */ |
| public final void writeChars (String value) throws IOException |
| { |
| int len = value.length(); |
| for (int i = 0; i < len; ++i) |
| writeChar (value.charAt(i)); |
| } |
| |
| /** |
| * 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 <\u007F>, 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". |
| * |
| * The value written can be read using the <code>readUTF</code> |
| * method in <code>DataInput</code>. |
| * |
| * @param value The <code>String</code> to write to the output in UTF format |
| * |
| * @exception IOException If an error occurs |
| * |
| * @see DataInput#readUTF |
| */ |
| public final synchronized void writeUTF(String value) throws IOException |
| { |
| int len = value.length(); |
| int sum = 0; |
| |
| for (int i = 0; i < len && sum <= 65535; ++i) |
| { |
| char c = value.charAt(i); |
| if (c >= '\u0001' && c <= '\u007f') |
| sum += 1; |
| else if (c == '\u0000' || (c >= '\u0080' && c <= '\u07ff')) |
| sum += 2; |
| else |
| sum += 3; |
| } |
| |
| if (sum > 65535) |
| throw new UTFDataFormatException (); |
| |
| writeShort (sum); |
| |
| for (int i = 0; i < len; ++i) |
| { |
| char c = value.charAt(i); |
| if (c >= '\u0001' && c <= '\u007f') |
| write (c); |
| else if (c == '\u0000' || (c >= '\u0080' && c <= '\u07ff')) |
| { |
| write (0xc0 | (0x1f & (c >> 6))); |
| write (0x80 | (0x3f & c)); |
| } |
| else |
| { |
| // JSL says the first byte should be or'd with 0xc0, but |
| // that is a typo. Unicode says 0xe0, and that is what is |
| // consistent with DataInputStream. |
| write (0xe0 | (0x0f & (c >> 12))); |
| write (0x80 | (0x3f & (c >> 6))); |
| write (0x80 | (0x3f & c)); |
| } |
| } |
| } |
| |
| } // class DataOutputStream |
| |