327 lines
12 KiB
Java
327 lines
12 KiB
Java
/* DataOutput.java -- Interface for writing data from a stream
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Copyright (C) 1998, 1999, 2001, 2003, 2005 Free Software Foundation, Inc.
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This file is part of GNU Classpath.
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GNU Classpath is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU Classpath is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU Classpath; see the file COPYING. If not, write to the
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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301 USA.
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Linking this library statically or dynamically with other modules is
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making a combined work based on this library. Thus, the terms and
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conditions of the GNU General Public License cover the whole
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combination.
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As a special exception, the copyright holders of this library give you
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permission to link this library with independent modules to produce an
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executable, regardless of the license terms of these independent
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modules, and to copy and distribute the resulting executable under
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terms of your choice, provided that you also meet, for each linked
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independent module, the terms and conditions of the license of that
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module. An independent module is a module which is not derived from
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or based on this library. If you modify this library, you may extend
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this exception to your version of the library, but you are not
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obligated to do so. If you do not wish to do so, delete this
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exception statement from your version. */
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package java.io;
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/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3
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* "The Java Language Specification", ISBN 0-201-63451-1
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* Status: Complete to version 1.1.
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*/
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/**
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* This interface is implemented by classes that can wrte data to streams
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* from Java primitive types. This data can subsequently be read back
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* by classes implementing the <code>DataInput</code> interface.
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*
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* @author Aaron M. Renn (arenn@urbanophile.com)
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* @author Tom Tromey (tromey@cygnus.com)
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*
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* @see DataInput
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*/
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public interface DataOutput
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{
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/**
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* This method writes a Java boolean value to an output stream. If
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* <code>value</code> is <code>true</code>, a byte with the value of
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* 1 will be written, otherwise a byte with the value of 0 will be
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* written.
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*
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* The value written can be read using the <code>readBoolean</code>
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* method in <code>DataInput</code>.
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*
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* @param value The boolean value to write
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*
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* @exception IOException If an error occurs
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*
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* @see DataInput#readBoolean
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*/
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void writeBoolean(boolean value) throws IOException;
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/**
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* This method writes a Java byte value to an output stream. The
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* byte to be written will be in the lowest 8 bits of the
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* <code>int</code> value passed.
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*
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* The value written can be read using the <code>readByte</code> or
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* <code>readUnsignedByte</code> methods in <code>DataInput</code>.
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*
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* @param value The int value to write
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*
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* @exception IOException If an error occurs
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*
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* @see DataInput#readByte
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* @see DataInput#readUnsignedByte
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*/
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void writeByte(int value) throws IOException;
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/**
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* This method writes a Java char value to an output stream. The
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* char to be written will be in the lowest 16 bits of the <code>int</code>
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* value passed. These bytes will be written "big endian". That is,
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* with the high byte written first in the following manner:
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* <p>
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* <code>byte0 = (byte)((value & 0xFF00) >> 8);<br>
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* byte1 = (byte)(value & 0x00FF);</code>
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* <p>
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*
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* The value written can be read using the <code>readChar</code>
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* method in <code>DataInput</code>.
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*
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* @param value The char value to write
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*
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* @exception IOException If an error occurs
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*
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* @see DataInput#readChar
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*/
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void writeChar(int value) throws IOException;
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/**
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* This method writes a Java short value to an output stream. The
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* char to be written will be in the lowest 16 bits of the <code>int</code>
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* value passed. These bytes will be written "big endian". That is,
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* with the high byte written first in the following manner:
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* <p>
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* <code>byte0 = (byte)((value & 0xFF00) >> 8);<br>
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* byte1 = (byte)(value & 0x00FF);</code>
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* <p>
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*
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* The value written can be read using the <code>readShort</code> and
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* <code>readUnsignedShort</code> methods in <code>DataInput</code>.
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*
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* @param value The int value to write as a 16-bit value
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*
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* @exception IOException If an error occurs
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*
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* @see DataInput#readShort
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* @see DataInput#readUnsignedShort
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*/
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void writeShort(int value) throws IOException;
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/**
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* This method writes a Java int value to an output stream. The 4 bytes
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* of the passed value will be written "big endian". That is, with
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* the high byte written first in the following manner:
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* <p>
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* <code>byte0 = (byte)((value & 0xFF000000) >> 24);<br>
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* byte1 = (byte)((value & 0x00FF0000) >> 16);<br>
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* byte2 = (byte)((value & 0x0000FF00) >> 8);<br>
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* byte3 = (byte)(value & 0x000000FF);</code>
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* <p>
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*
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* The value written can be read using the <code>readInt</code>
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* method in <code>DataInput</code>.
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*
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* @param value The int value to write
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*
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* @exception IOException If an error occurs
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*
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* @see DataInput#readInt
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*/
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void writeInt(int value) throws IOException;
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/**
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* This method writes a Java long value to an output stream. The 8 bytes
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* of the passed value will be written "big endian". That is, with
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* the high byte written first in the following manner:
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* <p>
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* <code>byte0 = (byte)((value & 0xFF00000000000000L) >> 56);<br>
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* byte1 = (byte)((value & 0x00FF000000000000L) >> 48);<br>
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* byte2 = (byte)((value & 0x0000FF0000000000L) >> 40);<br>
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* byte3 = (byte)((value & 0x000000FF00000000L) >> 32);<br>
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* byte4 = (byte)((value & 0x00000000FF000000L) >> 24);<br>
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* byte5 = (byte)((value & 0x0000000000FF0000L) >> 16);<br>
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* byte6 = (byte)((value & 0x000000000000FF00L) >> 8);<br>
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* byte7 = (byte)(value & 0x00000000000000FFL);</code>
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* <p>
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*
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* The value written can be read using the <code>readLong</code>
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* method in <code>DataInput</code>.
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*
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* @param value The long value to write
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*
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* @exception IOException If an error occurs
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*
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* @see DataInput#readLong
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*/
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void writeLong(long value) throws IOException;
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/**
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* This method writes a Java <code>float</code> value to the stream. This
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* value is written by first calling the method
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* <code>Float.floatToIntBits</code>
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* to retrieve an <code>int</code> representing the floating point number,
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* then writing this <code>int</code> value to the stream exactly the same
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* as the <code>writeInt()</code> method does.
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*
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* The value written can be read using the <code>readFloat</code>
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* method in <code>DataInput</code>.
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*
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* @param value The float value to write
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*
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* @exception IOException If an error occurs
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*
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* @see #writeInt
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* @see DataInput#readFloat
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* @see Float#floatToIntBits
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*/
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void writeFloat(float value) throws IOException;
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/**
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* This method writes a Java <code>double</code> value to the stream. This
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* value is written by first calling the method
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* <code>Double.doubleToLongBits</code>
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* to retrieve an <code>long</code> representing the floating point number,
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* then writing this <code>long</code> value to the stream exactly the same
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* as the <code>writeLong()</code> method does.
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*
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* The value written can be read using the <code>readDouble</code>
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* method in <code>DataInput</code>.
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*
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* @param value The double value to write
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*
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* @exception IOException If any other error occurs
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*
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* @see #writeLong
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* @see DataInput#readDouble
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* @see Double#doubleToLongBits
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*/
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void writeDouble(double value) throws IOException;
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/**
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* This method writes all the bytes in a <code>String</code> out to the
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* stream. One byte is written for each character in the
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* <code>String</code>.
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* The high eight bits of each character are discarded, thus this
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* method is inappropriate for completely representing Unicode characters.
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*
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* @param value The <code>String</code> to write
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*
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* @exception IOException If an error occurs
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*/
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void writeBytes(String value) throws IOException;
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/**
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* This method writes all the characters of a <code>String</code> to an
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* output stream as an array of <code>char</code>'s. Each character
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* is written using the method specified in the <code>writeChar</code>
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* method.
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*
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* @param value The String to write
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*
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* @exception IOException If an error occurs
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*
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* @see #writeChar(int)
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*/
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void writeChars(String value) throws IOException;
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/**
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* This method writes a Java <code>String</code> to the stream in a modified
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* UTF-8 format. First, two bytes are written to the stream indicating the
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* number of bytes to follow. This is written in the form of a Java
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* <code>short</code> value in the same manner used by the
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* <code>writeShort</code> method. Note that this is the number of
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* bytes in the
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* encoded <code>String</code> not the <code>String</code> length. Next
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* come the encoded characters. Each character in the <code>String</code>
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* is encoded as either one, two or three bytes. For characters in the
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* range of <code>\u0001</code> to <code>\u007F</code>, one byte is used.
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* The character
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* value goes into bits 0-7 and bit eight is 0. For characters in the range
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* of <code>\u0080</code> to <code>\u007FF</code>, two bytes are used. Bits
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* 6-10 of the character value are encoded bits 0-4 of the first byte, with
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* the high bytes having a value of "110". Bits 0-5 of the character value
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* are stored in bits 0-5 of the second byte, with the high bits set to
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* "10". This type of encoding is also done for the null character
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* <code>\u0000</code>. This eliminates any C style NUL character values
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* in the output. All remaining characters are stored as three bytes.
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* Bits 12-15 of the character value are stored in bits 0-3 of the first
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* byte. The high bits of the first bytes are set to "1110". Bits 6-11
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* of the character value are stored in bits 0-5 of the second byte. The
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* high bits of the second byte are set to "10". And bits 0-5 of the
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* character value are stored in bits 0-5 of byte three, with the high bits
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* of that byte set to "10".
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*
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* The value written can be read using the <code>readUTF</code>
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* method in <code>DataInput</code>.
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*
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* @param value The <code>String</code> to write
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*
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* @exception IOException If an error occurs
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*
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* @see DataInput#readUTF
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*/
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void writeUTF(String value) throws IOException;
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/**
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* This method writes an 8-bit value (passed into the method as a Java
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* <code>int</code>) to an output stream. The low 8 bits of the
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* passed value are written.
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*
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* @param value The <code>byte</code> to write to the output stream
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*
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* @exception IOException If an error occurs
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*/
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void write(int value) throws IOException;
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/**
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* This method writes the raw byte array passed in to the output stream.
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*
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* @param buf The byte array to write
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*
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* @exception IOException If an error occurs
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*/
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void write(byte[] buf) throws IOException;
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/**
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* This method writes raw bytes from the passed array <code>buf</code>
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* starting
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* <code>offset</code> bytes into the buffer. The number of bytes
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* written will be exactly <code>len</code>.
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*
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* @param buf The buffer from which to write the data
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* @param offset The offset into the buffer to start writing data from
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* @param len The number of bytes to write from the buffer to the output
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* stream
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*
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* @exception IOException If any other error occurs
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*/
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void write(byte[] buf, int offset, int len) throws IOException;
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} // interface DataOutput
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