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    */
writeString(DataOutputStream os, String string)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    */
readString(ByteBuffer bb)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 }
96