/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 com.google.wave.api.impl;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParseException;
import com.google.gson.JsonPrimitive;
import com.google.gson.JsonSerializationContext;
import com.google.gson.JsonSerializer;
import com.google.wave.api.Attachment;
import com.google.wave.api.Element;
import com.google.wave.api.ElementType;
import com.google.wave.api.FormElement;
import com.google.wave.api.Gadget;
import com.google.wave.api.Image;
import com.google.wave.api.Line;
import org.apache.commons.codec.binary.Base64;
import java.io.UnsupportedEncodingException;
import java.lang.reflect.Type;
import java.util.Map;
import java.util.Map.Entry;
/**
* Gson adaptor to serialize and deserialize {@link Element}.
*
* @author mprasetya@google.com (Marcel Prasetya)
*/
public class ElementGsonAdaptor implements JsonDeserializer<Element>,
JsonSerializer<Element> {
protected static final String TYPE_TAG = "type";
protected static final String PROPERTIES_TAG = "properties";
@Override
public Element deserialize(JsonElement json, Type typeOfT,
JsonDeserializationContext context) throws JsonParseException {
Element result = null;
ElementType type = ElementType.valueOfIgnoreCase(
json.getAsJsonObject().get(TYPE_TAG).getAsString());
Map<String, String> properties = context.deserialize(
json.getAsJsonObject().get(PROPERTIES_TAG), GsonFactory.STRING_MAP_TYPE);
if (FormElement.getFormElementTypes().contains(type)) {
result = new FormElement(type, properties);
} else if (type == ElementType.GADGET) {
result = new Gadget(properties);
} else if (type == ElementType.IMAGE) {
result = new Image(properties);
} else if (type == ElementType.ATTACHMENT) {
byte[] data = null;
String encodedData = properties.get(Attachment.DATA);
if (encodedData != null) {
try {
data = Base64.decodeBase64(encodedData.getBytes("UTF-8"));
} catch (UnsupportedEncodingException e) {
throw new JsonParseException("Couldn't convert to utf-8", e);
}
}
result = new Attachment(properties, data);
} else if (type == ElementType.LINE) {
result = new Line(properties);
} else {
result = new Element(type, properties);
}
return result;
}
@Override
public JsonElement serialize(Element src, Type typeOfSrc, JsonSerializationContext context) {
JsonObject jsonObject = new JsonObject();
jsonObject.addProperty(TYPE_TAG, src.getType().toString());
JsonObject properties = new JsonObject();
if (src.isAttachment()) {
Attachment attachment = (Attachment) src;
if (attachment.hasData()) {
byte[] encodedData = Base64.encodeBase64(attachment.getData());
try {
properties.add(Attachment.DATA, new JsonPrimitive(
new String(encodedData, "UTF-8")));
} catch (UnsupportedEncodingException e) {
// this shouldn't happen, so let it slide.
}
}
}
for (Entry<String, String> entry : src.getProperties().entrySet()) {
// Note: Gson's JsonObject and MapTypeAdapter don't escape the key
// automatically, so we have to manually escape it here by calling
// JsonSerializationContext.serialize(). Also, unfortunately, calling
// JsonPrimitive.toString() wraps the text inside double quotes, that we
// need to strip out.
String quotedKey = context.serialize(entry.getKey()).toString();
String key = quotedKey.substring(1, quotedKey.length() - 1);
JsonElement value = context.serialize(entry.getValue());
properties.add(key, value);
}
jsonObject.add(PROPERTIES_TAG, properties);
return jsonObject;
}
}