[RFA/JDWP] Signature.java

[Aaron Luchko <aluchko at redhat dot com>]

This class adds support for reading and writing the string type in the
JDWP spec http://java.sun.com/j2se/1.5.0/docs/guide/jpda/jdwp-spec.html

Aaron

ChangeLog
2005-06-29  Aaron Luchko  <aluchko@redhat.com>

        * gnu/classpath/jdwp/util/JdwpString.java: New file.

--- /dev/null	2005-06-09 16:29:11.371620296 -0400
+++ gnu/classpath/jdwp/util/JdwpString.java	2005-06-29 14:11:44.000000000 -0400
@@ -0,0 +1,95 @@
+/* JdwpString.java -- utility class to read and write jdwp strings
+   Copyright (C) 2005 Free Software Foundation
+ 
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+ 
+GNU Classpath 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 for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package gnu.classpath.jdwp.util;
+
+import gnu.classpath.jdwp.exception.JdwpInternalErrorException;
+
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+import java.nio.ByteBuffer;
+
+/**
+ * A class to compute the JDWP representation of Strings.
+ * 
+ * @author Aaron Luchko <aluchko@redhat.com>
+ */
+public class JdwpString
+{
+
+  /**
+   * Write this String to the outStream as a string understood by jdwp.
+   * 
+   * @param os write the String here
+   * @param string the String to write
+   * @throws IOException
+   */
+  public static void writeString(DataOutputStream os, String string)
+      throws IOException
+  {
+    // Get the bytes of the string as a string in UTF-8
+    byte[] strBytes = string.getBytes("UTF-8");
+    os.writeInt(strBytes.length);
+    os.write(strBytes);
+  }
+
+  /**
+   * Read a jdwp style string from the ByteBuffer.
+   * 
+   * @param bb contains the string
+   * @return the String that was read
+   * @throws JdwpInternalErrorException bb didn't contain a value UTF-8 string
+   */
+  public static String readString(ByteBuffer bb)
+      throws JdwpInternalErrorException
+  {
+    int length = bb.getInt();
+    byte[] strBytes = new byte[length];
+    bb.get(strBytes);
+    try
+      {
+        return new String(strBytes, "UTF-8");
+      }
+    catch (UnsupportedEncodingException ex)
+      {
+        // Any string from the VM should be in UTF-8 so an encoding error
+        // shouldn't be possible
+        throw new JdwpInternalErrorException(ex);
+      }
+  }
+}