1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27 package org.apache.http.impl.client;
28
29 import java.io.Closeable;
30 import java.io.IOException;
31 import java.util.concurrent.ExecutorService;
32 import java.util.concurrent.atomic.AtomicBoolean;
33
34 import org.apache.http.annotation.Contract;
35 import org.apache.http.annotation.ThreadingBehavior;
36 import org.apache.http.client.HttpClient;
37 import org.apache.http.client.ResponseHandler;
38 import org.apache.http.client.methods.HttpUriRequest;
39 import org.apache.http.concurrent.FutureCallback;
40 import org.apache.http.protocol.HttpContext;
41
42 /**
43 * HttpAsyncClientWithFuture wraps calls to execute with a {@link HttpRequestFutureTask}
44 * and schedules them using the provided executor service. Scheduled calls may be cancelled.
45 */
46 @Contract(threading = ThreadingBehavior.SAFE)
47 public class FutureRequestExecutionService implements Closeable {
48
49 private final HttpClient httpclient;
50 private final ExecutorService executorService;
51 private final FutureRequestExecutionMetricsnMetrics.html#FutureRequestExecutionMetrics">FutureRequestExecutionMetrics metrics = new FutureRequestExecutionMetrics();
52 private final AtomicBoolean closed = new AtomicBoolean(false);
53
54 /**
55 * Create a new FutureRequestExecutionService.
56 *
57 * @param httpclient
58 * you should tune your httpclient instance to match your needs. You should
59 * align the max number of connections in the pool and the number of threads
60 * in the executor; it doesn't make sense to have more threads than connections
61 * and if you have less connections than threads, the threads will just end up
62 * blocking on getting a connection from the pool.
63 * @param executorService
64 * any executorService will do here. E.g.
65 * {@link java.util.concurrent.Executors#newFixedThreadPool(int)}
66 */
67 public FutureRequestExecutionService(
68 final HttpClient httpclient,
69 final ExecutorService executorService) {
70 this.httpclient = httpclient;
71 this.executorService = executorService;
72 }
73
74 /**
75 * Schedule a request for execution.
76 *
77 * @param <T>
78 *
79 * @param request
80 * request to execute
81 * @param responseHandler
82 * handler that will process the response.
83 * @return HttpAsyncClientFutureTask for the scheduled request.
84 */
85 public <T> HttpRequestFutureTask<T> execute(
86 final HttpUriRequest request,
87 final HttpContext context,
88 final ResponseHandler<T> responseHandler) {
89 return execute(request, context, responseHandler, null);
90 }
91
92 /**
93 * Schedule a request for execution.
94 *
95 * @param <T>
96 *
97 * @param request
98 * request to execute
99 * @param context
100 * optional context; use null if not needed.
101 * @param responseHandler
102 * handler that will process the response.
103 * @param callback
104 * callback handler that will be called when the request is scheduled,
105 * started, completed, failed, or cancelled.
106 * @return HttpAsyncClientFutureTask for the scheduled request.
107 */
108 public <T> HttpRequestFutureTask<T> execute(
109 final HttpUriRequest request,
110 final HttpContext context,
111 final ResponseHandler<T> responseHandler,
112 final FutureCallback<T> callback) {
113 if(closed.get()) {
114 throw new IllegalStateException("Close has been called on this httpclient instance.");
115 }
116 metrics.getScheduledConnections().incrementAndGet();
117 final HttpRequestTaskCallable<T> callable = new HttpRequestTaskCallable<T>(
118 httpclient, request, context, responseHandler, callback, metrics);
119 final HttpRequestFutureTask<T> httpRequestFutureTask = new HttpRequestFutureTask<T>(
120 request, callable);
121 executorService.execute(httpRequestFutureTask);
122
123 return httpRequestFutureTask;
124 }
125
126 /**
127 * @return metrics gathered for this instance.
128 * @see FutureRequestExecutionMetrics
129 */
130 public FutureRequestExecutionMetrics metrics() {
131 return metrics;
132 }
133
134 @Override
135 public void close() throws IOException {
136 closed.set(true);
137 executorService.shutdownNow();
138 if (httpclient instanceof Closeable) {
139 ((Closeable) httpclient).close();
140 }
141 }
142 }