Added StringUtil.joinEscaped() and a unit test for said.

git-svn-id: https://samskivert.googlecode.com/svn/trunk@549 6335cc39-0255-0410-8fd6-9bcaacd3b74c

projects/samskivert/src/java/com/samskivert/util/StringUtil.java

@@ -1,5 +1,5 @@
 //
-// $Id: StringUtil.java,v 1.18 2002/01/22 15:46:56 shaper Exp $
+// $Id: StringUtil.java,v 1.19 2002/01/30 18:11:27 mdb Exp $
 //
 // samskivert library - useful routines for java programs
 // Copyright (C) 2001 Michael Bayne
@@ -351,6 +351,25 @@ public class StringUtil
         return vals;
     }
 
+    /**
+     * Joins an array of strings into a single string, separated by
+     * commas, and escaping commas that occur in the individual string
+     * values such that a subsequent call to {@link #parseStringArray}
+     * would recreated the string array properly.
+     */
+    public static String joinEscaped (String[] values)
+    {
+        StringBuffer buf = new StringBuffer();
+        int vlength = values.length;
+        for (int i = 0; i < vlength; i++) {
+            if (i > 0) {
+                buf.append(", ");
+            }
+            buf.append(replace(values[i], ",", ",,"));
+        }
+        return buf.toString();
+    }
+
     /**
      * Splits the supplied string into components based on the specified
      * separator character.

projects/samskivert/tests/src/java/com/samskivert/util/StringUtilTest.java

@@ -0,0 +1,52 @@
+//
+// $Id: StringUtilTest.java,v 1.1 2002/01/30 18:11:27 mdb Exp $
+//
+// samskivert library - useful routines for java programs
+// Copyright (C) 2001 Michael Bayne
+// 
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library 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
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.samskivert.util;
+
+import junit.framework.Test;
+import junit.framework.TestCase;
+
+import com.samskivert.Log;
+
+public class StringUtilTest extends TestCase
+{
+    public StringUtilTest ()
+    {
+        super(StringUtilTest.class.getName());
+    }
+
+    public void runTest ()
+    {
+        String source = "mary, had, a,, little, lamb, and, a, comma,,";
+
+        // split the source string into tokens
+        String[] tokens = StringUtil.parseStringArray(source);
+        assert("tokens.length == 7", tokens.length == 7);
+
+        // now join them back together
+        String joined = StringUtil.joinEscaped(tokens);
+        assert("joined.equals(source)", joined.equals(source));
+    }
+
+    public static Test suite ()
+    {
+        return new StringUtilTest();
+    }
+}