content: /*
   * 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.carbondata.core.metadata.datatype;
  
  import java.io.IOException;
  
  import org.apache.carbondata.core.util.DataTypeUtil;
  
  import com.google.gson.Gson;
  import com.google.gson.TypeAdapter;
  import com.google.gson.stream.JsonReader;
  import com.google.gson.stream.JsonToken;
  import com.google.gson.stream.JsonWriter;
  
  /**
   * This class is added to support backward compatibility with table info object, where DATATYPE
   * is string in old version(1.2) and OBJECT in new version(1.3)
   */
  public class DataTypeAdapter extends TypeAdapter<Object> {
  
    private Gson fallBack_original = new Gson();
  
    @Override
    public void write(JsonWriter jsonWriter, Object o) {
    }
  
    @Override
    public Object read(JsonReader jsonReader) throws IOException {
      JsonToken token = jsonReader.peek();
      if (token == JsonToken.STRING) {
        return DataTypeUtil.valueOf(jsonReader.nextString());
      } else {
        // use original deserializer logic
        return fallBack_original.fromJson(jsonReader, DataType.class);
      }
    }
  
  }
  