355 lines
14 KiB
Java
355 lines
14 KiB
Java
/*
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* Copyright (c) 1995, 2013, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Oracle designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Oracle in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package java.io;
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/**
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* The <code>DataOutput</code> interface provides
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* for converting data from any of the Java
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* primitive types to a series of bytes and
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* writing these bytes to a binary stream.
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* There is also a facility for converting
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* a <code>String</code> into
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* <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
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* format and writing the resulting series
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* of bytes.
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* <p>
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* For all the methods in this interface that
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* write bytes, it is generally true that if
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* a byte cannot be written for any reason,
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* an <code>IOException</code> is thrown.
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*
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* @author Frank Yellin
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* @see java.io.DataInput
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* @see java.io.DataOutputStream
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* @since 1.0
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*/
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public
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interface DataOutput {
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/**
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* Writes to the output stream the eight
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* low-order bits of the argument <code>b</code>.
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* The 24 high-order bits of <code>b</code>
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* are ignored.
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*
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* @param b the byte to be written.
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* @throws IOException if an I/O error occurs.
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*/
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void write(int b) throws IOException;
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/**
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* Writes to the output stream all the bytes in array <code>b</code>.
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* If <code>b</code> is <code>null</code>,
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* a <code>NullPointerException</code> is thrown.
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* If <code>b.length</code> is zero, then
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* no bytes are written. Otherwise, the byte
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* <code>b[0]</code> is written first, then
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* <code>b[1]</code>, and so on; the last byte
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* written is <code>b[b.length-1]</code>.
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*
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* @param b the data.
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* @throws IOException if an I/O error occurs.
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*/
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void write(byte b[]) throws IOException;
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/**
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* Writes <code>len</code> bytes from array
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* <code>b</code>, in order, to
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* the output stream. If <code>b</code>
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* is <code>null</code>, a <code>NullPointerException</code>
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* is thrown. If <code>off</code> is negative,
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* or <code>len</code> is negative, or <code>off+len</code>
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* is greater than the length of the array
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* <code>b</code>, then an <code>IndexOutOfBoundsException</code>
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* is thrown. If <code>len</code> is zero,
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* then no bytes are written. Otherwise, the
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* byte <code>b[off]</code> is written first,
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* then <code>b[off+1]</code>, and so on; the
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* last byte written is <code>b[off+len-1]</code>.
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*
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* @param b the data.
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* @param off the start offset in the data.
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* @param len the number of bytes to write.
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* @throws IOException if an I/O error occurs.
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*/
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void write(byte b[], int off, int len) throws IOException;
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/**
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* Writes a <code>boolean</code> value to this output stream.
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* If the argument <code>v</code>
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* is <code>true</code>, the value <code>(byte)1</code>
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* is written; if <code>v</code> is <code>false</code>,
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* the value <code>(byte)0</code> is written.
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* The byte written by this method may
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* be read by the <code>readBoolean</code>
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* method of interface <code>DataInput</code>,
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* which will then return a <code>boolean</code>
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* equal to <code>v</code>.
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*
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* @param v the boolean to be written.
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* @throws IOException if an I/O error occurs.
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*/
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void writeBoolean(boolean v) throws IOException;
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/**
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* Writes to the output stream the eight low-
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* order bits of the argument <code>v</code>.
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* The 24 high-order bits of <code>v</code>
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* are ignored. (This means that <code>writeByte</code>
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* does exactly the same thing as <code>write</code>
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* for an integer argument.) The byte written
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* by this method may be read by the <code>readByte</code>
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* method of interface <code>DataInput</code>,
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* which will then return a <code>byte</code>
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* equal to <code>(byte)v</code>.
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*
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* @param v the byte value to be written.
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* @throws IOException if an I/O error occurs.
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*/
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void writeByte(int v) throws IOException;
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/**
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* Writes two bytes to the output
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* stream to represent the value of the argument.
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* The byte values to be written, in the order
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* shown, are:
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* <pre>{@code
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* (byte)(0xff & (v >> 8))
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* (byte)(0xff & v)
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* }</pre> <p>
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* The bytes written by this method may be
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* read by the <code>readShort</code> method
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* of interface <code>DataInput</code> , which
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* will then return a <code>short</code> equal
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* to <code>(short)v</code>.
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*
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* @param v the <code>short</code> value to be written.
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* @throws IOException if an I/O error occurs.
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*/
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void writeShort(int v) throws IOException;
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/**
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* Writes a <code>char</code> value, which
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* is comprised of two bytes, to the
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* output stream.
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* The byte values to be written, in the order
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* shown, are:
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* <pre>{@code
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* (byte)(0xff & (v >> 8))
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* (byte)(0xff & v)
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* }</pre><p>
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* The bytes written by this method may be
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* read by the <code>readChar</code> method
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* of interface <code>DataInput</code> , which
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* will then return a <code>char</code> equal
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* to <code>(char)v</code>.
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*
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* @param v the <code>char</code> value to be written.
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* @throws IOException if an I/O error occurs.
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*/
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void writeChar(int v) throws IOException;
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/**
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* Writes an <code>int</code> value, which is
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* comprised of four bytes, to the output stream.
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* The byte values to be written, in the order
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* shown, are:
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* <pre>{@code
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* (byte)(0xff & (v >> 24))
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* (byte)(0xff & (v >> 16))
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* (byte)(0xff & (v >> 8))
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* (byte)(0xff & v)
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* }</pre><p>
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* The bytes written by this method may be read
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* by the <code>readInt</code> method of interface
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* <code>DataInput</code> , which will then
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* return an <code>int</code> equal to <code>v</code>.
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*
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* @param v the <code>int</code> value to be written.
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* @throws IOException if an I/O error occurs.
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*/
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void writeInt(int v) throws IOException;
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/**
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* Writes a <code>long</code> value, which is
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* comprised of eight bytes, to the output stream.
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* The byte values to be written, in the order
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* shown, are:
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* <pre>{@code
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* (byte)(0xff & (v >> 56))
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* (byte)(0xff & (v >> 48))
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* (byte)(0xff & (v >> 40))
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* (byte)(0xff & (v >> 32))
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* (byte)(0xff & (v >> 24))
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* (byte)(0xff & (v >> 16))
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* (byte)(0xff & (v >> 8))
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* (byte)(0xff & v)
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* }</pre><p>
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* The bytes written by this method may be
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* read by the <code>readLong</code> method
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* of interface <code>DataInput</code> , which
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* will then return a <code>long</code> equal
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* to <code>v</code>.
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*
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* @param v the <code>long</code> value to be written.
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* @throws IOException if an I/O error occurs.
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*/
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void writeLong(long v) throws IOException;
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/**
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* Writes a <code>float</code> value,
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* which is comprised of four bytes, to the output stream.
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* It does this as if it first converts this
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* <code>float</code> value to an <code>int</code>
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* in exactly the manner of the <code>Float.floatToIntBits</code>
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* method and then writes the <code>int</code>
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* value in exactly the manner of the <code>writeInt</code>
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* method. The bytes written by this method
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* may be read by the <code>readFloat</code>
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* method of interface <code>DataInput</code>,
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* which will then return a <code>float</code>
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* equal to <code>v</code>.
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*
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* @param v the <code>float</code> value to be written.
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* @throws IOException if an I/O error occurs.
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*/
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void writeFloat(float v) throws IOException;
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/**
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* Writes a <code>double</code> value,
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* which is comprised of eight bytes, to the output stream.
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* It does this as if it first converts this
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* <code>double</code> value to a <code>long</code>
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* in exactly the manner of the <code>Double.doubleToLongBits</code>
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* method and then writes the <code>long</code>
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* value in exactly the manner of the <code>writeLong</code>
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* method. The bytes written by this method
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* may be read by the <code>readDouble</code>
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* method of interface <code>DataInput</code>,
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* which will then return a <code>double</code>
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* equal to <code>v</code>.
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*
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* @param v the <code>double</code> value to be written.
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* @throws IOException if an I/O error occurs.
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*/
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void writeDouble(double v) throws IOException;
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/**
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* Writes a string to the output stream.
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* For every character in the string
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* <code>s</code>, taken in order, one byte
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* is written to the output stream. If
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* <code>s</code> is <code>null</code>, a <code>NullPointerException</code>
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* is thrown.<p> If <code>s.length</code>
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* is zero, then no bytes are written. Otherwise,
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* the character <code>s[0]</code> is written
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* first, then <code>s[1]</code>, and so on;
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* the last character written is <code>s[s.length-1]</code>.
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* For each character, one byte is written,
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* the low-order byte, in exactly the manner
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* of the <code>writeByte</code> method . The
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* high-order eight bits of each character
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* in the string are ignored.
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*
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* @param s the string of bytes to be written.
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* @throws IOException if an I/O error occurs.
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*/
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void writeBytes(String s) throws IOException;
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/**
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* Writes every character in the string <code>s</code>,
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* to the output stream, in order,
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* two bytes per character. If <code>s</code>
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* is <code>null</code>, a <code>NullPointerException</code>
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* is thrown. If <code>s.length</code>
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* is zero, then no characters are written.
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* Otherwise, the character <code>s[0]</code>
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* is written first, then <code>s[1]</code>,
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* and so on; the last character written is
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* <code>s[s.length-1]</code>. For each character,
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* two bytes are actually written, high-order
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* byte first, in exactly the manner of the
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* <code>writeChar</code> method.
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*
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* @param s the string value to be written.
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* @throws IOException if an I/O error occurs.
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*/
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void writeChars(String s) throws IOException;
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/**
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* Writes two bytes of length information
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* to the output stream, followed
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* by the
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* <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
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* representation
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* of every character in the string <code>s</code>.
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* If <code>s</code> is <code>null</code>,
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* a <code>NullPointerException</code> is thrown.
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* Each character in the string <code>s</code>
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* is converted to a group of one, two, or
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* three bytes, depending on the value of the
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* character.<p>
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* If a character <code>c</code>
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* is in the range <code>\u0001</code> through
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* <code>\u007f</code>, it is represented
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* by one byte:
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* <pre>(byte)c </pre> <p>
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* If a character <code>c</code> is <code>\u0000</code>
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* or is in the range <code>\u0080</code>
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* through <code>\u07ff</code>, then it is
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* represented by two bytes, to be written
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* in the order shown: <pre>{@code
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* (byte)(0xc0 | (0x1f & (c >> 6)))
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* (byte)(0x80 | (0x3f & c))
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* }</pre> <p> If a character
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* <code>c</code> is in the range <code>\u0800</code>
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* through <code>uffff</code>, then it is
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* represented by three bytes, to be written
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* in the order shown: <pre>{@code
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* (byte)(0xe0 | (0x0f & (c >> 12)))
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* (byte)(0x80 | (0x3f & (c >> 6)))
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* (byte)(0x80 | (0x3f & c))
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* }</pre> <p> First,
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* the total number of bytes needed to represent
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* all the characters of <code>s</code> is
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* calculated. If this number is larger than
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* <code>65535</code>, then a <code>UTFDataFormatException</code>
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* is thrown. Otherwise, this length is written
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* to the output stream in exactly the manner
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* of the <code>writeShort</code> method;
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* after this, the one-, two-, or three-byte
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* representation of each character in the
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* string <code>s</code> is written.<p> The
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* bytes written by this method may be read
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* by the <code>readUTF</code> method of interface
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* <code>DataInput</code> , which will then
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* return a <code>String</code> equal to <code>s</code>.
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*
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* @param s the string value to be written.
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* @throws IOException if an I/O error occurs.
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*/
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void writeUTF(String s) throws IOException;
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}
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