content: /**
   * Copyright (C) 2010-2016 eBusiness Information, Excilys Group
   *
   * 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.androidannotations.api.sharedpreferences;
  
  import java.io.IOException;
  import java.io.StringReader;
  import java.io.StringWriter;
  import java.util.Collections;
  import java.util.Set;
  import java.util.TreeSet;
  
  import org.xmlpull.v1.XmlPullParser;
  import org.xmlpull.v1.XmlPullParserException;
  import org.xmlpull.v1.XmlSerializer;
  
  import android.util.Log;
  import android.util.Xml;
  
  public final class SetXmlSerializer {
  
  	private static final String NAMESPACE = "";
  	private static final String STRING_TAG = "AA_string";
  	private static final String SET_TAG = "AA_set";
  
  	private SetXmlSerializer() {
  
  	}
  
  	public static String serialize(Set<String> set) {
  		if (set == null) {
  			set = Collections.emptySet();
  		}
  
  		StringWriter writer = new StringWriter();
  		XmlSerializer serializer = Xml.newSerializer();
  
  		try {
  			serializer.setOutput(writer);
  			serializer.startTag(NAMESPACE, SET_TAG);
  
  			for (String string : set) {
  				serializer.startTag(NAMESPACE, STRING_TAG) //
  						.text(string) //
  						.endTag(NAMESPACE, STRING_TAG);
  			}
  
  			serializer.endTag(NAMESPACE, SET_TAG) //
  					.endDocument();
  
  		} catch (IllegalArgumentException | IOException | IllegalStateException e) {
  			// should never happen
  		}
  
  		return writer.toString();
  	}
  
  	public static Set<String> deserialize(String data) {
  		Set<String> stringSet = new TreeSet<>();
  		XmlPullParser parser = Xml.newPullParser();
  
  		try {
  			parser.setInput(new StringReader(data));
  			parser.next();
  			parser.require(XmlPullParser.START_TAG, NAMESPACE, SET_TAG);
  
  			while (parser.next() != XmlPullParser.END_TAG) {
  				parser.require(XmlPullParser.START_TAG, NAMESPACE, STRING_TAG);
  
  				parser.next();
  				parser.require(XmlPullParser.TEXT, null, null);
  				stringSet.add(parser.getText());
  
  				parser.next();
  				parser.require(XmlPullParser.END_TAG, null, STRING_TAG);
  			}
  		} catch (XmlPullParserException e) {
  			Log.w("getStringSet", e);
  			return null;
  		} catch (IOException e) {
  			Log.w("getStringSet", e);
  			return null;
  		}
  
  		return stringSet;
  	}
  }
  