Source for gnu.classpath.jdwp.util.JdwpString

   1: /* JdwpString.java -- utility class to read and write jdwp strings
   2:    Copyright (C) 2005 Free Software Foundation
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: package gnu.classpath.jdwp.util;
  39: 
  40: import gnu.classpath.jdwp.exception.JdwpInternalErrorException;
  41: 
  42: import java.io.DataOutputStream;
  43: import java.io.IOException;
  44: import java.io.UnsupportedEncodingException;
  45: import java.nio.ByteBuffer;
  46: 
  47: /**
  48:  * A class to compute the JDWP representation of Strings.
  49:  *
  50:  * @author Aaron Luchko <aluchko@redhat.com>
  51:  */
  52: public class JdwpString
  53: {
  54: 
  55:   /**
  56:    * Write this String to the outStream as a string understood by jdwp.
  57:    *
  58:    * @param os write the String here
  59:    * @param string the String to write
  60:    * @throws IOException
  61:    */
  62:   public static void writeString(DataOutputStream os, String string)
  63:       throws IOException
  64:   {
  65:     // Get the bytes of the string as a string in UTF-8
  66:     byte[] strBytes = string.getBytes("UTF-8");
  67:     os.writeInt(strBytes.length);
  68:     os.write(strBytes);
  69:   }
  70: 
  71:   /**
  72:    * Read a jdwp style string from the ByteBuffer.
  73:    *
  74:    * @param bb contains the string
  75:    * @return the String that was read
  76:    * @throws JdwpInternalErrorException bb didn't contain a value UTF-8 string
  77:    */
  78:   public static String readString(ByteBuffer bb)
  79:       throws JdwpInternalErrorException
  80:   {
  81:     int length = bb.getInt();
  82:     byte[] strBytes = new byte[length];
  83:     bb.get(strBytes);
  84:     try
  85:       {
  86:         return new String(strBytes, "UTF-8");
  87:       }
  88:     catch (UnsupportedEncodingException ex)
  89:       {
  90:         // Any string from the VM should be in UTF-8 so an encoding error
  91:         // shouldn't be possible
  92:         throw new JdwpInternalErrorException(ex);
  93:       }
  94:   }
  95: }