Java tutorial
/** * 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.tajo.catalog.json; import com.google.gson.*; import org.apache.tajo.catalog.TableDesc; import java.lang.reflect.Type; public class TableDescAdapter implements JsonSerializer<TableDesc>, JsonDeserializer<TableDesc> { @Override public TableDesc deserialize(JsonElement json, Type type, JsonDeserializationContext ctx) throws JsonParseException { JsonObject jsonObject = json.getAsJsonObject(); String className = jsonObject.get("classname").getAsJsonPrimitive().getAsString(); Class clazz = null; try { clazz = Class.forName(className); } catch (ClassNotFoundException e) { e.printStackTrace(); throw new JsonParseException(e); } return ctx.deserialize(jsonObject.get("property"), clazz); } @Override public JsonElement serialize(TableDesc src, Type typeOfSrc, JsonSerializationContext context) { JsonObject jsonObj = new JsonObject(); String className = src.getClass().getCanonicalName(); jsonObj.addProperty("classname", className); if (src.getClass().getSimpleName().equals("TableDescImpl")) { src.initFromProto(); } JsonElement jsonElem = context.serialize(src); jsonObj.add("property", jsonElem); return jsonObj; } }