/**
* 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;
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();
builder.registerTypeAdapter(OpType.class, new OpType.JsonSerDer());
builder.registerTypeAdapter(Expr.class, new Expr.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);
}
}