带有定义超时的 JavaHTTP 客户端请求

我想使 BIT (内置测试)在我的云服务器的数量。我需要该请求在大超时时失败。

我要怎么用爪哇咖啡？

尝试下面这样的方法似乎行不通。

public class TestNodeAliveness {
public static NodeStatus nodeBIT(String elasticIP) throws ClientProtocolException, IOException {
HttpClient client = new DefaultHttpClient();
client.getParams().setIntParameter("http.connection.timeout", 1);


HttpUriRequest request = new HttpGet("http://192.168.20.43");
HttpResponse response = client.execute(request);


System.out.println(response.toString());
return null;
}




public static void main(String[] args) throws ClientProtocolException, IOException {
nodeBIT("");
}
}

——编辑: 澄清正在使用的图书馆——

我正在使用 apache 中的 httpclient，下面是相关的 pom.xml 部分

 <dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.0.1</version>
<type>jar</type>
</dependency>
308858 次浏览
小开

It looks like you are using the HttpClient API, which I know nothing about, but you could write something similar to this using core Java.

try {


HttpURLConnection con = (HttpURLConnection) new URL(url).openConnection();
con.setRequestMethod("HEAD");
con.setConnectTimeout(5000); //set timeout to 5 seconds
return (con.getResponseCode() == HttpURLConnection.HTTP_OK);


} catch (java.net.SocketTimeoutException e) {
return false;
} catch (java.io.IOException e) {
return false;
}
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最佳答案 
import org.apache.http.client.HttpClient;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;


...


// set the connection timeout value to 30 seconds (30000 milliseconds)
final HttpParams httpParams = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(httpParams, 30000);
client = new DefaultHttpClient(httpParams);
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I found that setting the time out settings in HttpConnectionParams and HttpConnectionManager did not solve our case. We're limited to using org.apache.commons.httpclient version 3.0.1.

I ended up using an java.util.concurrent.ExecutorService to monitor the HttpClient.executeMethod() call.

Here's a small, self-contained example

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.methods.EntityEnclosingMethod;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.methods.multipart.FilePart;
import org.apache.commons.httpclient.methods.multipart.MultipartRequestEntity;
import org.apache.commons.httpclient.methods.multipart.Part;
import java.io.File;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.*;


/**
* @author Jeff Kirby
* @since <pre>Jun 17, 2011</pre>
*/
public class Example {


private static final String SITE = "http://some.website.com/upload";
private static final int TIME_OUT_SECS = 5;


// upload a file and return the response as a string
public String post(File file) throws IOException, InterruptedException {
final Part[] multiPart = { new FilePart("file", file.getName(), file) };
final EntityEnclosingMethod post = new PostMethod(SITE);
post.setRequestEntity(new MultipartRequestEntity(multiPart, post.getParams()));
final ExecutorService executor = Executors.newSingleThreadExecutor();
final List<Future<Integer>> futures = executor.invokeAll(Arrays.asList(new KillableHttpClient(post)), TIME_OUT_SECS, TimeUnit.SECONDS);
executor.shutdown();
if(futures.get(0).isCancelled()) {
throw new IOException(SITE + " has timed out. It has taken more than " + TIME_OUT_SECS + " seconds to respond");
}
return post.getResponseBodyAsString();
}


private static class KillableHttpClient implements Callable<Integer> {


private final EntityEnclosingMethod post;


private KillableHttpClient(EntityEnclosingMethod post) {
this.post = post;
}


public Integer call() throws Exception {
return new HttpClient().executeMethod(post);
}
}
}
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HttpConnectionParams.setSoTimeout(params, 10*60*1000);// for 10 mins i have set the timeout

You can as well define your required time out.

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This was already mentioned in a comment by benvoliot above. But, I think it's worth a top-level post because it sure had me scratching my head. I'm posting this in case it helps someone else out.

I wrote a simple test client and the CoreConnectionPNames.CONNECTION_TIMEOUT timeout works perfectly in that case. The request gets canceled if the server doesn't respond.

Inside the server code I was actually trying to test however, the identical code never times out.

Changing it to time out on the socket connection activity (CoreConnectionPNames.SO_TIMEOUT) rather than the HTTP connection (CoreConnectionPNames.CONNECTION_TIMEOUT) fixed the problem for me.

Also, read the Apache docs carefully: http://hc.apache.org/httpcomponents-core-ga/httpcore/apidocs/org/apache/http/params/CoreConnectionPNames.html#CONNECTION_TIMEOUT

Note the bit that says

Please note this parameter can only be applied to connections that are bound to a particular local address.

I hope that saves someone else all the head scratching I went through. That will teach me not to read the documentation thoroughly!

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If you are using Http Client version 4.3 and above you should be using this:

RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(30 * 1000).build();
HttpClient httpClient = HttpClientBuilder.create().setDefaultRequestConfig(requestConfig).build();
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HttpParams is deprecated in the new Apache HTTPClient library. Using the code provided by Laz leads to deprecation warnings.

I suggest to use RequestConfig instead on your HttpGet or HttpPost instance: 

final RequestConfig params = RequestConfig.custom().setConnectTimeout(3000).setSocketTimeout(3000).build();
httpPost.setConfig(params);
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Op later stated they were using Apache Commons HttpClient 3.0.1

 HttpClient client = new HttpClient();
client.getHttpConnectionManager().getParams().setConnectionTimeout(5000);
client.getHttpConnectionManager().getParams().setSoTimeout(5000);
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The said method with highest up's by Laz is deprecated from version 4.3 onwards. Hence it would be better to user the Request Config Object and then build the HTTP Client

    private CloseableHttpClient createHttpClient()
{
CloseableHttpClient httpClient;
CommonHelperFunctions helperFunctions = new CommonHelperFunctions();
PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
cm.setMaxTotal(306);
cm.setDefaultMaxPerRoute(108);
RequestConfig requestConfig = RequestConfig.custom()
.setConnectTimeout(15000)
.setSocketTimeout(15000).build();
httpClient = HttpClients.custom()
.setConnectionManager(cm)
.setDefaultRequestConfig(requestConfig).build();
return httpClient;
}

The PoolingHttpClientConnectionManager is user to set the max default number of connections and the max number of conncetions per route. I have set it as 306 and 108 respectively. The default values will not be sufficient for most of the cases.

For setting Timeout: I have used the RequestConfig object. You can also set the property Connection Request Timeout for setting timeout for waiting for connection from Connection manager.


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