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* 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.
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*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
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package org.apache.http.examples;
import java.io.IOException;
import java.util.concurrent.Future;
import org.apache.http.ConnectionReuseStrategy;
import org.apache.http.HttpClientConnection;
import org.apache.http.HttpException;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequestInterceptor;
import org.apache.http.HttpResponse;
import org.apache.http.HttpVersion;
import org.apache.http.impl.DefaultConnectionReuseStrategy;
import org.apache.http.impl.pool.BasicConnFactory;
import org.apache.http.impl.pool.BasicConnPool;
import org.apache.http.impl.pool.BasicPoolEntry;
import org.apache.http.message.BasicHttpRequest;
import org.apache.http.params.HttpParams;
import org.apache.http.params.HttpProtocolParams;
import org.apache.http.params.SyncBasicHttpParams;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpContext;
import org.apache.http.protocol.HttpProcessor;
import org.apache.http.protocol.HttpRequestExecutor;
import org.apache.http.protocol.ImmutableHttpProcessor;
import org.apache.http.protocol.RequestConnControl;
import org.apache.http.protocol.RequestContent;
import org.apache.http.protocol.RequestExpectContinue;
import org.apache.http.protocol.RequestTargetHost;
import org.apache.http.protocol.RequestUserAgent;
import org.apache.http.util.EntityUtils;
/**
* Elemental example for executing multiple GET requests from different threads using a connection
* pool.
* <p>
* Please note the purpose of this application is demonstrate the usage of HttpCore APIs.
* It is NOT intended to demonstrate the most efficient way of building an HTTP client.
*/
public class ElementalPoolingHttpGet {
public static void main(String[] args) throws Exception {
final HttpParams params = new SyncBasicHttpParams();
HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
HttpProtocolParams.setContentCharset(params, "UTF-8");
HttpProtocolParams.setUserAgent(params, "Test/1.1");
HttpProtocolParams.setUseExpectContinue(params, true);
final HttpProcessor httpproc = new ImmutableHttpProcessor(new HttpRequestInterceptor[] {
// Required protocol interceptors
new RequestContent(),
new RequestTargetHost(),
// Recommended protocol interceptors
new RequestConnControl(),
new RequestUserAgent(),
new RequestExpectContinue()});
final HttpRequestExecutor httpexecutor = new HttpRequestExecutor();
final BasicConnPool pool = new BasicConnPool(new BasicConnFactory(params));
pool.setDefaultMaxPerRoute(2);
pool.setMaxTotal(2);
HttpHost[] targets = {
new HttpHost("www.google.com", 80),
new HttpHost("www.yahoo.com", 80),
new HttpHost("www.apache.com", 80)
};
class WorkerThread extends Thread {
private final HttpHost target;
WorkerThread(final HttpHost target) {
super();
this.target = target;
}
@Override
public void run() {
try {
Future<BasicPoolEntry> future = pool.lease(this.target, null);
boolean reusable = false;
BasicPoolEntry entry = future.get();
try {
HttpClientConnection conn = entry.getConnection();
HttpContext context = new BasicHttpContext(null);
context.setAttribute(ExecutionContext.HTTP_CONNECTION, conn);
context.setAttribute(ExecutionContext.HTTP_TARGET_HOST, this.target);
BasicHttpRequest request = new BasicHttpRequest("GET", "/");
System.out.println(">> Request URI: " + request.getRequestLine().getUri());
request.setParams(params);
httpexecutor.preProcess(request, httpproc, context);
HttpResponse response = httpexecutor.execute(request, conn, context);
response.setParams(params);
httpexecutor.postProcess(response, httpproc, context);
System.out.println("<< Response: " + response.getStatusLine());
System.out.println(EntityUtils.toString(response.getEntity()));
ConnectionReuseStrategy connStrategy = new DefaultConnectionReuseStrategy();
reusable = connStrategy.keepAlive(response, context);
} catch (IOException ex) {
throw ex;
} catch (HttpException ex) {
throw ex;
} finally {
if (reusable) {
System.out.println("Connection kept alive...");
}
pool.release(entry, reusable);
}
} catch (Exception ex) {
System.out.println("Request to " + this.target + " failed: " + ex.getMessage());
}
}
};
WorkerThread[] workers = new WorkerThread[targets.length];
for (int i = 0; i < workers.length; i++) {
workers[i] = new WorkerThread(targets[i]);
}
for (int i = 0; i < workers.length; i++) {
workers[i].start();
}
for (int i = 0; i < workers.length; i++) {
workers[i].join();
}
}
}