我尝试了以下 Apache http 客户端示例：
我将最大池大小设置为 5 并运行十个线程。运行此代码后，当我检查 netstat 时，我看到 10 个 TCP 连接正在打开。我期待连接被重用。为什么是这样 ？我错过了什么吗？
代码片段如下：
public class ClientMultiThreadedExecution {
public static void main(String[] args) throws Exception {
SchemeRegistry schemeRegistry = new SchemeRegistry();
schemeRegistry.register(
new Scheme("http", 18080, PlainSocketFactory.getSocketFactory()));
ThreadSafeClientConnManager cm = new ThreadSafeClientConnManager(schemeRegistry);
cm.setDefaultMaxPerRoute(5);
cm.setMaxTotal(5);
HttpClient httpclient = new DefaultHttpClient(cm);
try {
// create an array of URIs to perform GETs on
String uri = "http://test.webservice.com:18080/TestServlet";
String data = "This is a test message";
System.out.println("Started at: " + new Date());
// creating 10 threads
PostThread[] threads = new PostThread[10];
for (int i = 0; i < threads.length; i++) {
HttpPost httpPost = new HttpPost(uri);
threads[i] = new PostThread(httpclient, httpPost, data, i + 1);
threads[i].start();
//Thread.sleep(1000);
}
// join the threads
for (int j = 0; j < threads.length; j++) {
threads[j].join();
}
} finally {
// When HttpClient instance is no longer needed,
// shut down the connection manager to ensure
// immediate deallocation of all system resources
System.out.println("Ended at: " + new Date());
httpclient.getConnectionManager().shutdown();
}
}
/**
* A thread that performs a POST.
*/
static class PostThread extends Thread {
private final HttpClient httpClient;
private final HttpContext context;
private final HttpPost httpPost;
private final int id;
private final String data;
public PostThread(HttpClient httpClient, HttpPost httpPost, String data, int id) {
this.httpClient = httpClient;
this.context = new BasicHttpContext();
this.httpPost = httpPost;
this.id = id;
this.data = data;
}
/**
* Executes the PostMethod and prints some status information.
*/
@Override
public void run() {
//System.out.println(id + " - about to get something from " + httpPost.getURI());
try {
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
nameValuePairs.add(new BasicNameValuePair("XML",data));
httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs,"UTF-8"));
// execute the method
HttpResponse response = httpClient.execute(httpPost, context);
//System.out.println(id + " - get executed");
// get the response body as an array of bytes
if(response.getStatusLine().getStatusCode() == HttpStatus.SC_OK)
System.out.println("Success");
//Is this step necessary ?? Need to check as only status code is required
//httpPost.abort();
//HttpEntity entity = response.getEntity();
//And this ?
//EntityUtils.consume(entity);
} catch (Exception e) {
httpPost.abort();
System.out.println(id + " - error: " + e);
}
}
}}