/** * 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 backtype.storm.drpc; import backtype.storm.task.TopologyContext; import backtype.storm.topology.BasicOutputCollector; import backtype.storm.topology.OutputFieldsDeclarer; import backtype.storm.topology.base.BaseBasicBolt; import backtype.storm.tuple.Fields; import backtype.storm.tuple.Tuple; import backtype.storm.tuple.Values; import java.util.Map; import java.util.Random; import backtype.storm.utils.Utils; public class PrepareRequest extends BaseBasicBolt { public static final String ARGS_STREAM = Utils.DEFAULT_STREAM_ID; public static final String RETURN_STREAM = "ret"; public static final String ID_STREAM = "id"; Random rand; @Override public void prepare(Map map, TopologyContext context) { rand = new Random(); } @Override public void execute(Tuple tuple, BasicOutputCollector collector) { String args = tuple.getString(0); String returnInfo = tuple.getString(1); long requestId = rand.nextLong(); collector.emit(ARGS_STREAM, new Values(requestId, args)); collector.emit(RETURN_STREAM, new Values(requestId, returnInfo)); collector.emit(ID_STREAM, new Values(requestId)); } public void declareOutputFields(OutputFieldsDeclarer declarer) { declarer.declareStream(ARGS_STREAM, new Fields("request", "args")); declarer.declareStream(RETURN_STREAM, new Fields("request", "return")); declarer.declareStream(ID_STREAM, new Fields("request")); } }