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 * Copyright (c) 1995, 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package java.io;

/**

 * The {@code DataOutput} interface provides

 * for converting data from any of the Java

 * primitive types to a series of bytes and

 * writing these bytes to a binary stream.

 * There is  also a facility for converting

 * a {@code String} into

 * <a href="DataInput.html#modified-utf-8">modified UTF-8</a>

 * format and writing the resulting series

 * of bytes.

 * <p>

 * For all the methods in this interface that

 * write bytes, it is generally true that if

 * a byte cannot be written for any reason,

 * an {@code IOException} is thrown.

 *

 * @author  Frank Yellin

 * @see     java.io.DataInput

 * @see     java.io.DataOutputStream

 * @since   1.0

 */

public interface DataOutput {

    /**

     * Writes to the output stream the eight

     * low-order bits of the argument {@code b}.

     * The 24 high-order  bits of {@code b}

     * are ignored.

     *

     * @param      b   the byte to be written.

     * @throws     IOException  if an I/O error occurs.

     */

    void write(int b) throws IOException;

    /**

     * Writes to the output stream all the bytes in array {@code b}.

     * If {@code b} is {@code null},

     * a {@code NullPointerException} is thrown.

     * If {@code b.length} is zero, then

     * no bytes are written. Otherwise, the byte

     * {@code b[0]} is written first, then

     * {@code b[1]}, and so on; the last byte

     * written is {@code b[b.length-1]}.

     *

     * @param      b   the data.

     * @throws     IOException  if an I/O error occurs.

     */

    void write(byte b[]) throws IOException;

    /**

     * Writes {@code len} bytes from array

     * {@code b}, in order,  to

     * the output stream.  If {@code b}

     * is {@code null}, a {@code NullPointerException}

     * is thrown.  If {@code off} is negative,

     * or {@code len} is negative, or {@code off+len}

     * is greater than the length of the array

     * {@code b}, then an {@code IndexOutOfBoundsException}

     * is thrown.  If {@code len} is zero,

     * then no bytes are written. Otherwise, the

     * byte {@code b[off]} is written first,

     * then {@code b[off+1]}, and so on; the

     * last byte written is {@code b[off+len-1]}.

     *

     * @param      b     the data.

     * @param      off   the start offset in the data.

     * @param      len   the number of bytes to write.

     * @throws     IOException  if an I/O error occurs.

     */

    void write(byte b[], int off, int len) throws IOException;

    /**

     * Writes a {@code boolean} value to this output stream.

     * If the argument {@code v}

     * is {@code true}, the value {@code (byte)1}

     * is written; if {@code v} is {@code false},

     * the  value {@code (byte)0} is written.

     * The byte written by this method may

     * be read by the {@code readBoolean}

     * method of interface {@code DataInput},

     * which will then return a {@code boolean}

     * equal to {@code v}.

     *

     * @param      v   the boolean to be written.

     * @throws     IOException  if an I/O error occurs.

     */

    void writeBoolean(boolean v) throws IOException;

    /**

     * Writes to the output stream the eight low-

     * order bits of the argument {@code v}.

     * The 24 high-order bits of {@code v}

     * are ignored. (This means  that {@code writeByte}

     * does exactly the same thing as {@code write}

     * for an integer argument.) The byte written

     * by this method may be read by the {@code readByte}

     * method of interface {@code DataInput},

     * which will then return a {@code byte}

     * equal to {@code (byte)v}.

     *

     * @param      v   the byte value to be written.

     * @throws     IOException  if an I/O error occurs.

     */

    void writeByte(int v) throws IOException;

    /**

     * Writes two bytes to the output

     * stream to represent the value of the argument.

     * The byte values to be written, in the  order

     * shown, are:

     * <pre>{@code

     * (byte)(0xff & (v >> 8))

     * (byte)(0xff & v)

     * }</pre> <p>

     * The bytes written by this method may be

     * read by the {@code readShort} method

     * of interface {@code DataInput} , which

     * will then return a {@code short} equal

     * to {@code (short)v}.

     *

     * @param      v   the {@code short} value to be written.

     * @throws     IOException  if an I/O error occurs.

     */

    void writeShort(int v) throws IOException;

    /**

     * Writes a {@code char} value, which

     * is comprised of two bytes, to the

     * output stream.

     * The byte values to be written, in the  order

     * shown, are:

     * <pre>{@code

     * (byte)(0xff & (v >> 8))

     * (byte)(0xff & v)

     * }</pre><p>

     * The bytes written by this method may be

     * read by the {@code readChar} method

     * of interface {@code DataInput} , which

     * will then return a {@code char} equal

     * to {@code (char)v}.

     *

     * @param      v   the {@code char} value to be written.

     * @throws     IOException  if an I/O error occurs.

     */

    void writeChar(int v) throws IOException;

    /**

     * Writes an {@code int} value, which is

     * comprised of four bytes, to the output stream.

     * The byte values to be written, in the  order

     * shown, are:

     * <pre>{@code

     * (byte)(0xff & (v >> 24))

     * (byte)(0xff & (v >> 16))

     * (byte)(0xff & (v >>  8))

     * (byte)(0xff & v)

     * }</pre><p>

     * The bytes written by this method may be read

     * by the {@code readInt} method of interface

     * {@code DataInput} , which will then

     * return an {@code int} equal to {@code v}.

     *

     * @param      v   the {@code int} value to be written.

     * @throws     IOException  if an I/O error occurs.

     */

    void writeInt(int v) throws IOException;

    /**

     * Writes a {@code long} value, which is

     * comprised of eight bytes, to the output stream.

     * The byte values to be written, in the  order

     * shown, are:

     * <pre>{@code

     * (byte)(0xff & (v >> 56))

     * (byte)(0xff & (v >> 48))

     * (byte)(0xff & (v >> 40))

     * (byte)(0xff & (v >> 32))

     * (byte)(0xff & (v >> 24))

     * (byte)(0xff & (v >> 16))

     * (byte)(0xff & (v >>  8))

     * (byte)(0xff & v)

     * }</pre><p>

     * The bytes written by this method may be

     * read by the {@code readLong} method

     * of interface {@code DataInput} , which

     * will then return a {@code long} equal

     * to {@code v}.

     *

     * @param      v   the {@code long} value to be written.

     * @throws     IOException  if an I/O error occurs.

     */

    void writeLong(long v) throws IOException;

    /**

     * Writes a {@code float} value,

     * which is comprised of four bytes, to the output stream.

     * It does this as if it first converts this

     * {@code float} value to an {@code int}

     * in exactly the manner of the {@code Float.floatToIntBits}

     * method  and then writes the {@code int}

     * value in exactly the manner of the  {@code writeInt}

     * method.  The bytes written by this method

     * may be read by the {@code readFloat}

     * method of interface {@code DataInput},

     * which will then return a {@code float}

     * equal to {@code v}.

     *

     * @param      v   the {@code float} value to be written.

     * @throws     IOException  if an I/O error occurs.

     */

    void writeFloat(float v) throws IOException;

    /**

     * Writes a {@code double} value,

     * which is comprised of eight bytes, to the output stream.

     * It does this as if it first converts this

     * {@code double} value to a {@code long}

     * in exactly the manner of the {@code Double.doubleToLongBits}

     * method  and then writes the {@code long}

     * value in exactly the manner of the  {@code writeLong}

     * method. The bytes written by this method

     * may be read by the {@code readDouble}

     * method of interface {@code DataInput},

     * which will then return a {@code double}

     * equal to {@code v}.

     *

     * @param      v   the {@code double} value to be written.

     * @throws     IOException  if an I/O error occurs.

     */

    void writeDouble(double v) throws IOException;

    /**

     * Writes a string to the output stream.

     * For every character in the string

     * {@code s},  taken in order, one byte

     * is written to the output stream.  If

     * {@code s} is {@code null}, a {@code NullPointerException}

     * is thrown.<p>  If {@code s.length}

     * is zero, then no bytes are written. Otherwise,

     * the character {@code s[0]} is written

     * first, then {@code s[1]}, and so on;

     * the last character written is {@code s[s.length-1]}.

     * For each character, one byte is written,

     * the low-order byte, in exactly the manner

     * of the {@code writeByte} method . The

     * high-order eight bits of each character

     * in the string are ignored.

     *

     * @param      s   the string of bytes to be written.

     * @throws     IOException  if an I/O error occurs.

     */

    void writeBytes(String s) throws IOException;

    /**

     * Writes every character in the string {@code s},

     * to the output stream, in order,

     * two bytes per character. If {@code s}

     * is {@code null}, a {@code NullPointerException}

     * is thrown.  If {@code s.length}

     * is zero, then no characters are written.

     * Otherwise, the character {@code s[0]}

     * is written first, then {@code s[1]},

     * and so on; the last character written is

     * {@code s[s.length-1]}. For each character,

     * two bytes are actually written, high-order

     * byte first, in exactly the manner of the

     * {@code writeChar} method.

     *

     * @param      s   the string value to be written.

     * @throws     IOException  if an I/O error occurs.

     */

    void writeChars(String s) throws IOException;

    /**

     * Writes two bytes of length information

     * to the output stream, followed

     * by the

     * <a href="DataInput.html#modified-utf-8">modified UTF-8</a>

     * representation

     * of  every character in the string {@code s}.

     * If {@code s} is {@code null},

     * a {@code NullPointerException} is thrown.

     * Each character in the string {@code s}

     * is converted to a group of one, two, or

     * three bytes, depending on the value of the

     * character.<p>

     * If a character {@code c}

     * is in the range <code>&#92;u0001</code> through

     * <code>&#92;u007f</code>, it is represented

     * by one byte:

     * <pre>(byte)c </pre>  <p>

     * If a character {@code c} is <code>&#92;u0000</code>

     * or is in the range <code>&#92;u0080</code>

     * through <code>&#92;u07ff</code>, then it is

     * represented by two bytes, to be written

     * in the order shown: <pre>{@code

     * (byte)(0xc0 | (0x1f & (c >> 6)))

     * (byte)(0x80 | (0x3f & c))

     * }</pre> <p> If a character

     * {@code c} is in the range <code>&#92;u0800</code>

     * through {@code uffff}, then it is

     * represented by three bytes, to be written

     * in the order shown: <pre>{@code

     * (byte)(0xe0 | (0x0f & (c >> 12)))

     * (byte)(0x80 | (0x3f & (c >>  6)))

     * (byte)(0x80 | (0x3f & c))

     * }</pre>  <p> First,

     * the total number of bytes needed to represent

     * all the characters of {@code s} is

     * calculated. If this number is larger than

     * {@code 65535}, then a {@code UTFDataFormatException}

     * is thrown. Otherwise, this length is written

     * to the output stream in exactly the manner

     * of the {@code writeShort} method;

     * after this, the one-, two-, or three-byte

     * representation of each character in the

     * string {@code s} is written.<p>  The

     * bytes written by this method may be read

     * by the {@code readUTF} method of interface

     * {@code DataInput} , which will then

     * return a {@code String} equal to {@code s}.

     *

     * @param      s   the string value to be written.

     * @throws     IOException  if an I/O error occurs.

     */

    void writeUTF(String s) throws IOException;

}