| /** |
| * 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 com.sun.jersey.api.client.ClientResponse; |
| import com.sun.jersey.api.client.WebResource; |
| |
| import com.datatorrent.api.DefaultOutputPort; |
| import com.datatorrent.api.annotation.OutputPortFieldAnnotation; |
| |
| /** |
| * This is the base implementation of an HTTP get operator, |
| * which extracts query parameters from incoming tuples. |
| * The operator then makes GET calls using the extracted parameters and given url. |
| * Subclasses should implement the methods required to extract query parameters and process responses. |
| * <p> |
| * If the output port is connected, the response is processed |
| * </p> |
| * @displayName Abstract HTTP Query Input |
| * @category Input |
| * @tags http, input operator |
| * |
| * @param <INPUT> tuple type of input port |
| * @param <OUTPUT> tuple type of output port |
| * @since 1.0.2 |
| */ |
| @org.apache.hadoop.classification.InterfaceStability.Evolving |
| public abstract class AbstractHttpGetOperator<INPUT, OUTPUT> extends AbstractHttpOperator<INPUT> |
| { |
| /** |
| * The output port which emits retrieved tuples. |
| */ |
| @OutputPortFieldAnnotation(optional = true) |
| public final transient DefaultOutputPort<OUTPUT> output = new DefaultOutputPort<OUTPUT>(); |
| |
| @Override |
| protected void processTuple(INPUT t) |
| { |
| WebResource wr = getResourceWithQueryParams(t); |
| if (output.isConnected()) { |
| ClientResponse response = wr.get(ClientResponse.class); |
| processResponse(response); |
| } else { |
| wr.get(ClientResponse.class); |
| } |
| } |
| |
| protected abstract WebResource getResourceWithQueryParams(INPUT t); |
| |
| protected abstract void processResponse(ClientResponse response); |
| |
| } |