src/main/java/org/apache/pirk/response/wideskies/ResponseDeserializer.java

/*
 * 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 org.apache.pirk.response.wideskies;

import com.google.gson.Gson;
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.reflect.TypeToken;
import org.apache.pirk.query.wideskies.QueryDeserializer;
import org.apache.pirk.query.wideskies.QueryInfo;

import java.lang.reflect.Type;
import java.math.BigInteger;
import java.util.TreeMap;

/**
 * Custom deserializer for Response class for Gson.
 */
public class ResponseDeserializer implements JsonDeserializer<Response>
{

  private static final Gson gson = new Gson();

  @Override
  public Response deserialize(JsonElement jsonElement, Type type, JsonDeserializationContext jsonDeserializationContext) throws JsonParseException
  {
    final JsonObject jsonObject = jsonElement.getAsJsonObject();
    long responseVersion = jsonObject.get("responseVersion").getAsLong();
    if (responseVersion != Response.responseSerialVersionUID)
    {
      throw new JsonParseException("\"Attempt to deserialize unsupported query version. Supported: \"\n"
          + "          + Response.responseSerialVersionUID + \"; Received: \" + responseVersion");
    }
    QueryInfo queryInfo = QueryDeserializer.deserializeInfo(jsonObject.get("queryInfo").getAsJsonObject());
    Response response = new Response(queryInfo);
    TreeMap<Integer,BigInteger> responseElements = gson.fromJson(jsonObject.get("responseElements"), new TypeToken<TreeMap<Integer,BigInteger>>()
    {}.getType());
    response.setResponseElements(responseElements);
    return response;
  }
}