/** * 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.algebra; import com.google.gson.Gson; import com.google.gson.GsonBuilder; import org.apache.tajo.algebra.CreateTable.PartitionMethodDescExpr; public class JsonHelper { private static JsonHelper instance; private GsonBuilder builder; private Gson gson; static { instance = new JsonHelper(); } private JsonHelper() { initBuilder(); gson = builder.create(); } private void initBuilder() { builder = new GsonBuilder().setPrettyPrinting(). excludeFieldsWithoutExposeAnnotation(); builder.registerTypeAdapter(OpType.class, new OpType.JsonSerDer()); builder.registerTypeAdapter(Expr.class, new Expr.JsonSerDer()); builder.registerTypeAdapter(PartitionMethodDescExpr.class, new PartitionMethodDescExpr.JsonSerDer()); } public static Gson getInstance() { return instance.gson; } public static String toJson(Object obj) { return instance.gson.toJson(obj); } public static <T> T fromJson(String json, Class<T> clazz) { return instance.gson.fromJson(json, clazz); } }