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.gobblin.runtime.spec_serde; import java.io.IOException; import java.io.StringReader; import java.lang.reflect.Type; import java.net.URI; import java.net.URISyntaxException; import java.util.ArrayList; import java.util.HashSet; import java.util.List; import java.util.Properties; import java.util.Set; import com.google.gson.JsonDeserializationContext; import com.google.gson.JsonDeserializer; import com.google.gson.JsonElement; import com.google.gson.JsonObject; import com.google.gson.JsonParseException; import com.typesafe.config.Config; import com.typesafe.config.ConfigFactory; import org.apache.gobblin.runtime.api.FlowSpec; import org.apache.gobblin.runtime.api.Spec; public class FlowSpecDeserializer implements JsonDeserializer<FlowSpec> { @Override public FlowSpec deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) { JsonObject jsonObject = json.getAsJsonObject(); String uri = jsonObject.get(FlowSpecSerializer.FLOW_SPEC_URI_KEY).getAsString(); String version = jsonObject.get(FlowSpecSerializer.FLOW_SPEC_VERSION_KEY).getAsString(); String description = jsonObject.get(FlowSpecSerializer.FLOW_SPEC_DESCRIPTION_KEY).getAsString(); Config config = ConfigFactory .parseString(jsonObject.get(FlowSpecSerializer.FLOW_SPEC_CONFIG_KEY).getAsString()); Properties properties = new Properties(); try { properties.load(new StringReader( jsonObject.get(FlowSpecSerializer.FLOW_SPEC_CONFIG_AS_PROPERTIES_KEY).getAsString())); } catch (IOException e) { throw new JsonParseException(e); } Set<URI> templateURIs = new HashSet<>(); try { for (JsonElement template : jsonObject.get(FlowSpecSerializer.FLOW_SPEC_TEMPLATE_URIS_KEY) .getAsJsonArray()) { templateURIs.add(new URI(template.getAsString())); } } catch (URISyntaxException e) { throw new JsonParseException(e); } List<Spec> childSpecs = new ArrayList<>(); for (JsonElement spec : jsonObject.get(FlowSpecSerializer.FLOW_SPEC_CHILD_SPECS_KEY).getAsJsonArray()) { childSpecs.add(context.deserialize(spec, FlowSpec.class)); } FlowSpec.Builder builder = FlowSpec.builder(uri).withVersion(version).withDescription(description) .withConfig(config).withConfigAsProperties(properties); if (!templateURIs.isEmpty()) { builder = builder.withTemplates(templateURIs); } if (!childSpecs.isEmpty()) { builder = builder.withChildSpecs(childSpecs); } return builder.build(); } }