| /** |
| * 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 com.datatorrent.lib.io; |
| |
| import java.io.IOException; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import javax.validation.constraints.NotNull; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import com.datatorrent.common.util.PubSubMessageCodec; |
| |
| /** |
| * This operator reads JSON objects from the given URL and converts them into maps. |
| * <p></p> |
| * @displayName Pub Sub Web Socket Input |
| * @category Input |
| * @tags http, websocket |
| * |
| * @since 0.3.2 |
| */ |
| public class PubSubWebSocketInputOperator<T> extends WebSocketInputOperator<T> |
| { |
| private static final Logger LOG = LoggerFactory.getLogger(PubSubWebSocketInputOperator.class); |
| private String topic = null; |
| private transient PubSubMessageCodec<Object> codec; |
| |
| public PubSubWebSocketInputOperator() |
| { |
| this.codec = new PubSubMessageCodec<Object>(mapper); |
| } |
| |
| /** |
| * The pub sub topic to subscribe to. |
| * @param topic The pub sub topic to subscribe to. |
| */ |
| public void setTopic(String topic) |
| { |
| this.topic = topic; |
| } |
| |
| /** |
| * Gets pub sub topic to subscribe to. |
| * @return The pub sub topic to subscribe to. |
| */ |
| @NotNull |
| public String getTopic() |
| { |
| return topic; |
| } |
| |
| @SuppressWarnings("unchecked") |
| @Override |
| protected T convertMessage(String message) throws IOException |
| { |
| Map<String, Object> map = mapper.readValue(message, HashMap.class); |
| return (T)map.get("data"); |
| } |
| |
| @Override |
| public void run() |
| { |
| super.run(); |
| try { |
| connection.sendMessage(PubSubMessageCodec.constructSubscribeMessage(topic, codec)); |
| } catch (IOException ex) { |
| LOG.error("Exception caught", ex); |
| } |
| } |
| |
| } |