Java tutorial
/* * Copyright 2019 ThoughtWorks, Inc. * * Licensed 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 com.thoughtworks.go.api.util; import com.google.gson.Gson; import com.google.gson.GsonBuilder; import com.google.gson.JsonElement; import com.google.gson.JsonParseException; import com.thoughtworks.go.api.representers.JsonReader; import org.apache.commons.lang3.StringUtils; import java.lang.reflect.Type; import java.util.Map; public class GsonTransformer { private static final Gson GSON = new GsonBuilder().create(); private GsonTransformer() { } public static GsonTransformer getInstance() { return SingletonHolder.INSTANCE; } public JsonReader jsonReaderFrom(String string) { try { if (StringUtils.isBlank(string)) { string = "{}"; } return new JsonReader(GSON.fromJson(string, JsonElement.class).getAsJsonObject()); } catch (Exception e) { throw new JsonParseException(e); } } public JsonReader jsonReaderFrom(Map map) { try { return new JsonReader(GSON.toJsonTree(map).getAsJsonObject()); } catch (Exception e) { throw new JsonParseException(e); } } public <T> T fromJson(String string, Class<T> classOfT) { return GSON.fromJson(string, classOfT); } public <T> T fromJson(String string, Type classOfT) { return GSON.fromJson(string, classOfT); } private static class SingletonHolder { private static final GsonTransformer INSTANCE = new GsonTransformer(); } }