| /** |
| * 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.net.URI; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import javax.validation.constraints.NotNull; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import com.sun.jersey.api.client.Client; |
| import com.sun.jersey.api.client.ClientResponse; |
| import com.sun.jersey.api.client.WebResource; |
| |
| import com.datatorrent.api.Context.OperatorContext; |
| import com.datatorrent.api.DefaultOutputPort; |
| |
| /** |
| * This is a base implementation for an HTTP input operator that reads from a given url using the HTTP GET command like an input stream. |
| * Subclasses must implement the method which handles the response to the HTTP GET request. |
| * <p></p> |
| * @displayName Abstract HTTP Input |
| * @category Input |
| * @tags http, input operator |
| * |
| * @since 0.3.2 |
| */ |
| @org.apache.hadoop.classification.InterfaceStability.Evolving |
| public abstract class AbstractHttpInputOperator<T> extends SimpleSinglePortInputOperator<T> implements Runnable |
| { |
| /** |
| * The output port which emits retrieved tuples. |
| */ |
| public final transient DefaultOutputPort<String> rawOutput = new DefaultOutputPort<String>(); |
| private static final Logger LOG = LoggerFactory.getLogger(AbstractHttpInputOperator.class); |
| /** |
| * Timeout interval for reading from server. 0 or negative indicates no timeout. |
| */ |
| public int readTimeoutMillis = 0; |
| /** |
| * The URL of the web service resource for the POST request. |
| */ |
| @NotNull |
| private URI url; |
| private Map<String, String> headers = new HashMap<String, String>(); |
| private transient Client wsClient; |
| private transient WebResource resource; |
| |
| /** |
| * The url to read from. |
| * @param u The url to read from. |
| */ |
| public void setUrl(URI u) |
| { |
| url = u; |
| } |
| |
| /** |
| * Sets the url to read from. |
| * @return The url to read from. |
| */ |
| public URI getUrl() |
| { |
| return url; |
| } |
| |
| public void setHeader(String key, String value) |
| { |
| headers.put(key, value); |
| } |
| |
| @Override |
| public void setup(OperatorContext context) |
| { |
| wsClient = Client.create(); |
| wsClient.setFollowRedirects(true); |
| wsClient.setReadTimeout(readTimeoutMillis); |
| resource = wsClient.resource(url.toString()); // side step "not absolute URL" after serialization |
| LOG.info("URL: {}", url); |
| } |
| |
| @Override |
| public void teardown() |
| { |
| if (wsClient != null) { |
| wsClient.destroy(); |
| } |
| super.teardown(); |
| } |
| |
| public abstract void processResponse(ClientResponse response) throws IOException; |
| |
| @Override |
| public void run() |
| { |
| while (super.isActive()) { |
| try { |
| WebResource.Builder builder = resource.getRequestBuilder(); |
| |
| for (Map.Entry<String, String> entry : headers.entrySet()) { |
| builder = builder.header(entry.getKey(), entry.getValue()); |
| } |
| |
| ClientResponse response = builder.get(ClientResponse.class); |
| processResponse(response); |
| } catch (Exception e) { |
| LOG.error("Error reading from " + resource.getURI(), e); |
| } |
| |
| try { |
| Thread.sleep(500); |
| } catch (InterruptedException e) { |
| LOG.info("Exiting IO loop {}.", e.toString()); |
| break; |
| } |
| } |
| } |
| |
| } |