Create smack.util.stringencoder for Base64, Base32,…

Use Android's Base64 implementation when on Android, otherwise, when on
Java7, use the existing one.

smack-java7/src/main/java/org/jivesoftware/smack/java7/Java7SmackInitializer.java

@@ -20,12 +20,18 @@ import java.util.List;
 
 import org.jivesoftware.smack.SmackConfiguration;
 import org.jivesoftware.smack.initializer.SimpleSmackInitializer;
+import org.jivesoftware.smack.util.stringencoder.Base64;
+import org.jivesoftware.smack.util.stringencoder.Base64UrlSafeEncoder;
+import org.jivesoftware.smack.util.stringencoder.java7.Java7Base64Encoder;
+import org.jivesoftware.smack.util.stringencoder.java7.Java7Base64UrlSafeEncoder;
 
 public class Java7SmackInitializer extends SimpleSmackInitializer {
 
     @Override
     public List<Exception> initialize() {
         SmackConfiguration.setDefaultHostnameVerifier(new Java7HostnameVerifier());
+        Base64.setEncoder(Java7Base64Encoder.getInstance());
+        Base64UrlSafeEncoder.setEncoder(Java7Base64UrlSafeEncoder.getInstance());
         return null;
     }
 

smack-java7/src/main/java/org/jivesoftware/smack/util/stringencoder/java7/Java7Base64Encoder.java

@@ -0,0 +1,64 @@
+/**
+ *
+ * Copyright the original author or authors
+ *
+ * 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.stringencoder.java7;
+
+import java.io.UnsupportedEncodingException;
+
+import org.jivesoftware.smack.util.StringUtils;
+
+/**
+ * A Base 64 encoding implementation.
+ * @author Florian Schmaus
+ */
+public class Java7Base64Encoder implements org.jivesoftware.smack.util.stringencoder.Base64.Encoder {
+
+    private static Java7Base64Encoder instance = new Java7Base64Encoder();
+
+    private Java7Base64Encoder() {
+        // Use getInstance()
+    }
+
+    public static Java7Base64Encoder getInstance() {
+        return instance;
+    }
+
+    @Override
+    public byte[] decode(String string) {
+        return Base64.decode(string);
+    }
+
+    @Override
+    public byte[] decode(byte[] input, int offset, int len) {
+        return Base64.decode(input, offset, len, 0);
+    }
+
+    @Override
+    public String encodeToString(byte[] input, int offset, int len) {
+        return Base64.encodeBytes(input, offset, len);
+    }
+
+    @Override
+    public byte[] encode(byte[] input, int offset, int len) {
+        String string = encodeToString(input, offset, len);
+        try {
+            return string.getBytes(StringUtils.USASCII);
+        } catch (UnsupportedEncodingException e) {
+            throw new AssertionError(e);
+        }
+    }
+
+}

smack-java7/src/main/java/org/jivesoftware/smack/util/stringencoder/java7/Java7Base64UrlSafeEncoder.java

@@ -0,0 +1,53 @@
+/**
+ *
+ * Copyright the original author or authors
+ *
+ * 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.stringencoder.java7;
+
+import org.jivesoftware.smack.util.stringencoder.StringEncoder;
+
+
+/**
+ * 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>.
+ * </p>
+ * 
+ * @author Robin Collier
+ */
+public class Java7Base64UrlSafeEncoder implements StringEncoder {
+
+    private static Java7Base64UrlSafeEncoder instance = new Java7Base64UrlSafeEncoder();
+
+    private Java7Base64UrlSafeEncoder() {
+        // Use getInstance()
+    }
+
+    public static Java7Base64UrlSafeEncoder 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));
+    }
+
+}