| /** |
| * 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.hadoop.tools.rumen.state; |
| |
| import java.io.IOException; |
| |
| import com.fasterxml.jackson.core.JsonParser; |
| import com.fasterxml.jackson.core.JsonProcessingException; |
| import com.fasterxml.jackson.databind.DeserializationContext; |
| import com.fasterxml.jackson.databind.ObjectMapper; |
| import com.fasterxml.jackson.databind.deser.std.StdDeserializer; |
| import com.fasterxml.jackson.databind.node.ObjectNode; |
| import org.apache.hadoop.tools.rumen.state.StatePool.StatePair; |
| |
| /** |
| * Rumen JSON deserializer for deserializing the {@link State} object. |
| */ |
| public class StateDeserializer extends StdDeserializer<StatePair> { |
| public StateDeserializer() { |
| super(StatePair.class); |
| } |
| |
| @Override |
| public StatePair deserialize(JsonParser parser, |
| DeserializationContext context) |
| throws IOException, JsonProcessingException { |
| ObjectMapper mapper = (ObjectMapper) parser.getCodec(); |
| // set the state-pair object tree |
| ObjectNode statePairObject = (ObjectNode) mapper.readTree(parser); |
| Class<?> stateClass = null; |
| |
| try { |
| stateClass = |
| Class.forName(statePairObject.get("className").textValue().trim()); |
| } catch (ClassNotFoundException cnfe) { |
| throw new RuntimeException("Invalid classname!", cnfe); |
| } |
| |
| String stateJsonString = statePairObject.get("state").toString(); |
| State state = (State) mapper.readValue(stateJsonString, stateClass); |
| |
| return new StatePair(state); |
| } |
| } |