Home » openjdk-7 » java » io » [javadoc | source]

    1   /*
    2    * Copyright (c) 1995, 2006, Oracle and/or its affiliates. All rights reserved.
    3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
    4    *
    5    * This code is free software; you can redistribute it and/or modify it
    6    * under the terms of the GNU General Public License version 2 only, as
    7    * published by the Free Software Foundation.  Oracle designates this
    8    * particular file as subject to the "Classpath" exception as provided
    9    * by Oracle in the LICENSE file that accompanied this code.
   10    *
   11    * This code is distributed in the hope that it will be useful, but WITHOUT
   12    * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   13    * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   14    * version 2 for more details (a copy is included in the LICENSE file that
   15    * accompanied this code).
   16    *
   17    * You should have received a copy of the GNU General Public License version
   18    * 2 along with this work; if not, write to the Free Software Foundation,
   19    * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   20    *
   21    * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   22    * or visit www.oracle.com if you need additional information or have any
   23    * questions.
   24    */
   25   
   26   package java.io;
   27   
   28   /**
   29    * The <code>DataOutput</code> interface provides
   30    * for converting data from any of the Java
   31    * primitive types to a series of bytes and
   32    * writing these bytes to a binary stream.
   33    * There is  also a facility for converting
   34    * a <code>String</code> into
   35    * <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
   36    * format and writing the resulting series
   37    * of bytes.
   38    * <p>
   39    * For all the methods in this interface that
   40    * write bytes, it is generally true that if
   41    * a byte cannot be written for any reason,
   42    * an <code>IOException</code> is thrown.
   43    *
   44    * @author  Frank Yellin
   45    * @see     java.io.DataInput
   46    * @see     java.io.DataOutputStream
   47    * @since   JDK1.0
   48    */
   49   public
   50   interface DataOutput {
   51       /**
   52        * Writes to the output stream the eight
   53        * low-order bits of the argument <code>b</code>.
   54        * The 24 high-order  bits of <code>b</code>
   55        * are ignored.
   56        *
   57        * @param      b   the byte to be written.
   58        * @throws     IOException  if an I/O error occurs.
   59        */
   60       void write(int b) throws IOException;
   61   
   62       /**
   63        * Writes to the output stream all the bytes in array <code>b</code>.
   64        * If <code>b</code> is <code>null</code>,
   65        * a <code>NullPointerException</code> is thrown.
   66        * If <code>b.length</code> is zero, then
   67        * no bytes are written. Otherwise, the byte
   68        * <code>b[0]</code> is written first, then
   69        * <code>b[1]</code>, and so on; the last byte
   70        * written is <code>b[b.length-1]</code>.
   71        *
   72        * @param      b   the data.
   73        * @throws     IOException  if an I/O error occurs.
   74        */
   75       void write(byte b[]) throws IOException;
   76   
   77       /**
   78        * Writes <code>len</code> bytes from array
   79        * <code>b</code>, in order,  to
   80        * the output stream.  If <code>b</code>
   81        * is <code>null</code>, a <code>NullPointerException</code>
   82        * is thrown.  If <code>off</code> is negative,
   83        * or <code>len</code> is negative, or <code>off+len</code>
   84        * is greater than the length of the array
   85        * <code>b</code>, then an <code>IndexOutOfBoundsException</code>
   86        * is thrown.  If <code>len</code> is zero,
   87        * then no bytes are written. Otherwise, the
   88        * byte <code>b[off]</code> is written first,
   89        * then <code>b[off+1]</code>, and so on; the
   90        * last byte written is <code>b[off+len-1]</code>.
   91        *
   92        * @param      b     the data.
   93        * @param      off   the start offset in the data.
   94        * @param      len   the number of bytes to write.
   95        * @throws     IOException  if an I/O error occurs.
   96        */
   97       void write(byte b[], int off, int len) throws IOException;
   98   
   99       /**
  100        * Writes a <code>boolean</code> value to this output stream.
  101        * If the argument <code>v</code>
  102        * is <code>true</code>, the value <code>(byte)1</code>
  103        * is written; if <code>v</code> is <code>false</code>,
  104        * the  value <code>(byte)0</code> is written.
  105        * The byte written by this method may
  106        * be read by the <code>readBoolean</code>
  107        * method of interface <code>DataInput</code>,
  108        * which will then return a <code>boolean</code>
  109        * equal to <code>v</code>.
  110        *
  111        * @param      v   the boolean to be written.
  112        * @throws     IOException  if an I/O error occurs.
  113        */
  114       void writeBoolean(boolean v) throws IOException;
  115   
  116       /**
  117        * Writes to the output stream the eight low-
  118        * order bits of the argument <code>v</code>.
  119        * The 24 high-order bits of <code>v</code>
  120        * are ignored. (This means  that <code>writeByte</code>
  121        * does exactly the same thing as <code>write</code>
  122        * for an integer argument.) The byte written
  123        * by this method may be read by the <code>readByte</code>
  124        * method of interface <code>DataInput</code>,
  125        * which will then return a <code>byte</code>
  126        * equal to <code>(byte)v</code>.
  127        *
  128        * @param      v   the byte value to be written.
  129        * @throws     IOException  if an I/O error occurs.
  130        */
  131       void writeByte(int v) throws IOException;
  132   
  133       /**
  134        * Writes two bytes to the output
  135        * stream to represent the value of the argument.
  136        * The byte values to be written, in the  order
  137        * shown, are: <p>
  138        * <pre><code>
  139        * (byte)(0xff &amp; (v &gt;&gt; 8))
  140        * (byte)(0xff &amp; v)
  141        * </code> </pre> <p>
  142        * The bytes written by this method may be
  143        * read by the <code>readShort</code> method
  144        * of interface <code>DataInput</code> , which
  145        * will then return a <code>short</code> equal
  146        * to <code>(short)v</code>.
  147        *
  148        * @param      v   the <code>short</code> value to be written.
  149        * @throws     IOException  if an I/O error occurs.
  150        */
  151       void writeShort(int v) throws IOException;
  152   
  153       /**
  154        * Writes a <code>char</code> value, which
  155        * is comprised of two bytes, to the
  156        * output stream.
  157        * The byte values to be written, in the  order
  158        * shown, are:
  159        * <p><pre><code>
  160        * (byte)(0xff &amp; (v &gt;&gt; 8))
  161        * (byte)(0xff &amp; v)
  162        * </code></pre><p>
  163        * The bytes written by this method may be
  164        * read by the <code>readChar</code> method
  165        * of interface <code>DataInput</code> , which
  166        * will then return a <code>char</code> equal
  167        * to <code>(char)v</code>.
  168        *
  169        * @param      v   the <code>char</code> value to be written.
  170        * @throws     IOException  if an I/O error occurs.
  171        */
  172       void writeChar(int v) throws IOException;
  173   
  174       /**
  175        * Writes an <code>int</code> value, which is
  176        * comprised of four bytes, to the output stream.
  177        * The byte values to be written, in the  order
  178        * shown, are:
  179        * <p><pre><code>
  180        * (byte)(0xff &amp; (v &gt;&gt; 24))
  181        * (byte)(0xff &amp; (v &gt;&gt; 16))
  182        * (byte)(0xff &amp; (v &gt;&gt; &#32; &#32;8))
  183        * (byte)(0xff &amp; v)
  184        * </code></pre><p>
  185        * The bytes written by this method may be read
  186        * by the <code>readInt</code> method of interface
  187        * <code>DataInput</code> , which will then
  188        * return an <code>int</code> equal to <code>v</code>.
  189        *
  190        * @param      v   the <code>int</code> value to be written.
  191        * @throws     IOException  if an I/O error occurs.
  192        */
  193       void writeInt(int v) throws IOException;
  194   
  195       /**
  196        * Writes a <code>long</code> value, which is
  197        * comprised of eight bytes, to the output stream.
  198        * The byte values to be written, in the  order
  199        * shown, are:
  200        * <p><pre><code>
  201        * (byte)(0xff &amp; (v &gt;&gt; 56))
  202        * (byte)(0xff &amp; (v &gt;&gt; 48))
  203        * (byte)(0xff &amp; (v &gt;&gt; 40))
  204        * (byte)(0xff &amp; (v &gt;&gt; 32))
  205        * (byte)(0xff &amp; (v &gt;&gt; 24))
  206        * (byte)(0xff &amp; (v &gt;&gt; 16))
  207        * (byte)(0xff &amp; (v &gt;&gt;  8))
  208        * (byte)(0xff &amp; v)
  209        * </code></pre><p>
  210        * The bytes written by this method may be
  211        * read by the <code>readLong</code> method
  212        * of interface <code>DataInput</code> , which
  213        * will then return a <code>long</code> equal
  214        * to <code>v</code>.
  215        *
  216        * @param      v   the <code>long</code> value to be written.
  217        * @throws     IOException  if an I/O error occurs.
  218        */
  219       void writeLong(long v) throws IOException;
  220   
  221       /**
  222        * Writes a <code>float</code> value,
  223        * which is comprised of four bytes, to the output stream.
  224        * It does this as if it first converts this
  225        * <code>float</code> value to an <code>int</code>
  226        * in exactly the manner of the <code>Float.floatToIntBits</code>
  227        * method  and then writes the <code>int</code>
  228        * value in exactly the manner of the  <code>writeInt</code>
  229        * method.  The bytes written by this method
  230        * may be read by the <code>readFloat</code>
  231        * method of interface <code>DataInput</code>,
  232        * which will then return a <code>float</code>
  233        * equal to <code>v</code>.
  234        *
  235        * @param      v   the <code>float</code> value to be written.
  236        * @throws     IOException  if an I/O error occurs.
  237        */
  238       void writeFloat(float v) throws IOException;
  239   
  240       /**
  241        * Writes a <code>double</code> value,
  242        * which is comprised of eight bytes, to the output stream.
  243        * It does this as if it first converts this
  244        * <code>double</code> value to a <code>long</code>
  245        * in exactly the manner of the <code>Double.doubleToLongBits</code>
  246        * method  and then writes the <code>long</code>
  247        * value in exactly the manner of the  <code>writeLong</code>
  248        * method. The bytes written by this method
  249        * may be read by the <code>readDouble</code>
  250        * method of interface <code>DataInput</code>,
  251        * which will then return a <code>double</code>
  252        * equal to <code>v</code>.
  253        *
  254        * @param      v   the <code>double</code> value to be written.
  255        * @throws     IOException  if an I/O error occurs.
  256        */
  257       void writeDouble(double v) throws IOException;
  258   
  259       /**
  260        * Writes a string to the output stream.
  261        * For every character in the string
  262        * <code>s</code>,  taken in order, one byte
  263        * is written to the output stream.  If
  264        * <code>s</code> is <code>null</code>, a <code>NullPointerException</code>
  265        * is thrown.<p>  If <code>s.length</code>
  266        * is zero, then no bytes are written. Otherwise,
  267        * the character <code>s[0]</code> is written
  268        * first, then <code>s[1]</code>, and so on;
  269        * the last character written is <code>s[s.length-1]</code>.
  270        * For each character, one byte is written,
  271        * the low-order byte, in exactly the manner
  272        * of the <code>writeByte</code> method . The
  273        * high-order eight bits of each character
  274        * in the string are ignored.
  275        *
  276        * @param      s   the string of bytes to be written.
  277        * @throws     IOException  if an I/O error occurs.
  278        */
  279       void writeBytes(String s) throws IOException;
  280   
  281       /**
  282        * Writes every character in the string <code>s</code>,
  283        * to the output stream, in order,
  284        * two bytes per character. If <code>s</code>
  285        * is <code>null</code>, a <code>NullPointerException</code>
  286        * is thrown.  If <code>s.length</code>
  287        * is zero, then no characters are written.
  288        * Otherwise, the character <code>s[0]</code>
  289        * is written first, then <code>s[1]</code>,
  290        * and so on; the last character written is
  291        * <code>s[s.length-1]</code>. For each character,
  292        * two bytes are actually written, high-order
  293        * byte first, in exactly the manner of the
  294        * <code>writeChar</code> method.
  295        *
  296        * @param      s   the string value to be written.
  297        * @throws     IOException  if an I/O error occurs.
  298        */
  299       void writeChars(String s) throws IOException;
  300   
  301       /**
  302        * Writes two bytes of length information
  303        * to the output stream, followed
  304        * by the
  305        * <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
  306        * representation
  307        * of  every character in the string <code>s</code>.
  308        * If <code>s</code> is <code>null</code>,
  309        * a <code>NullPointerException</code> is thrown.
  310        * Each character in the string <code>s</code>
  311        * is converted to a group of one, two, or
  312        * three bytes, depending on the value of the
  313        * character.<p>
  314        * If a character <code>c</code>
  315        * is in the range <code>&#92;u0001</code> through
  316        * <code>&#92;u007f</code>, it is represented
  317        * by one byte:<p>
  318        * <pre>(byte)c </pre>  <p>
  319        * If a character <code>c</code> is <code>&#92;u0000</code>
  320        * or is in the range <code>&#92;u0080</code>
  321        * through <code>&#92;u07ff</code>, then it is
  322        * represented by two bytes, to be written
  323        * in the order shown:<p> <pre><code>
  324        * (byte)(0xc0 | (0x1f &amp; (c &gt;&gt; 6)))
  325        * (byte)(0x80 | (0x3f &amp; c))
  326        *  </code></pre>  <p> If a character
  327        * <code>c</code> is in the range <code>&#92;u0800</code>
  328        * through <code>uffff</code>, then it is
  329        * represented by three bytes, to be written
  330        * in the order shown:<p> <pre><code>
  331        * (byte)(0xe0 | (0x0f &amp; (c &gt;&gt; 12)))
  332        * (byte)(0x80 | (0x3f &amp; (c &gt;&gt;  6)))
  333        * (byte)(0x80 | (0x3f &amp; c))
  334        *  </code></pre>  <p> First,
  335        * the total number of bytes needed to represent
  336        * all the characters of <code>s</code> is
  337        * calculated. If this number is larger than
  338        * <code>65535</code>, then a <code>UTFDataFormatException</code>
  339        * is thrown. Otherwise, this length is written
  340        * to the output stream in exactly the manner
  341        * of the <code>writeShort</code> method;
  342        * after this, the one-, two-, or three-byte
  343        * representation of each character in the
  344        * string <code>s</code> is written.<p>  The
  345        * bytes written by this method may be read
  346        * by the <code>readUTF</code> method of interface
  347        * <code>DataInput</code> , which will then
  348        * return a <code>String</code> equal to <code>s</code>.
  349        *
  350        * @param      s   the string value to be written.
  351        * @throws     IOException  if an I/O error occurs.
  352        */
  353       void writeUTF(String s) throws IOException;
  354   }

Home » openjdk-7 » java » io » [javadoc | source]