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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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
 * modified UTF-8
 * format and writing the resulting series
 * of bytes.
 * 

* 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: *

{@code
     * (byte)(0xff & (v >> 8))
     * (byte)(0xff & v)
     * }

* 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: *

{@code
     * (byte)(0xff & (v >> 8))
     * (byte)(0xff & v)
     * }

* 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: *

{@code
     * (byte)(0xff & (v >> 24))
     * (byte)(0xff & (v >> 16))
     * (byte)(0xff & (v >>  8))
     * (byte)(0xff & v)
     * }

* 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: *

{@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)
     * }

* 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.

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 * modified UTF-8 * 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.

* If a character {@code c} * is in the range \u0001 through * \u007f, it is represented * by one byte: *

(byte)c 

* If a character {@code c} is \u0000 * or is in the range \u0080 * through \u07ff, then it is * represented by two bytes, to be written * in the order shown:

{@code
     * (byte)(0xc0 | (0x1f & (c >> 6)))
     * (byte)(0x80 | (0x3f & c))
     * }

If a character * {@code c} is in the range \u0800 * through {@code uffff}, then it is * represented by three bytes, to be written * in the order shown:

{@code
     * (byte)(0xe0 | (0x0f & (c >> 12)))
     * (byte)(0x80 | (0x3f & (c >>  6)))
     * (byte)(0x80 | (0x3f & c))
     * }

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.

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; }





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