SMACK-361 Changed default for filename encoding to Base 32 (which should work on all file systems) and added a Base 64 filename and url safe implementation of the StringEncoder.

git-svn-id: http://svn.igniterealtime.org/svn/repos/smack/branches/smack_3_3_0@13619 b35dd754-fafc-0310-a699-88a17e54d16e

source/org/jivesoftware/smack/util/Base64FileUrlEncoder.java

@@ -0,0 +1,48 @@
+/**
+ * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jivesoftware.smack.util;
+
+
+/**
+ * A Base 64 encoding implementation that generates filename and Url safe encodings.
+ * 
+ * <p>
+ * Note: This does NOT produce standard Base 64 encodings, but a variant as defined in 
+ * Section 4 of RFC3548:
+ * <a href="http://www.faqs.org/rfcs/rfc3548.html">http://www.faqs.org/rfcs/rfc3548.html</a>.
+ * 
+ * @author Robin Collier
+ */
+public class Base64FileUrlEncoder implements StringEncoder {
+
+    private static Base64FileUrlEncoder instance = new Base64FileUrlEncoder();
+
+    private Base64FileUrlEncoder() {
+        // Use getInstance()
+    }
+
+    public static Base64FileUrlEncoder getInstance() {
+        return instance;
+    }
+
+    public String encode(String s) {
+        return Base64.encodeBytes(s.getBytes(), Base64.URL_SAFE);
+    }
+
+    public String decode(String s) {
+        return new String(Base64.decode(s, Base64.URL_SAFE));
+    }
+
+}