How to perform HTTP cleanup with Java?

Question

I am trying to execute PURGE with an HttpUrlConnection as follows:

private void callVarnish(URL url) { HttpURLConnection conn = null; try { conn = (HttpURLConnection) url.openConnection(); conn.setRequestMethod(PURGE_METHOD); conn.setDoOutput(true); conn.setInstanceFollowRedirects(true); conn.setRequestProperty("Host", "www.somehost.com"); conn.connect(); System.out.print(conn.getResponseCode() + " " + conn.getResponseMessage()); } catch (Exception e) { log.error("Could not call varnish: " + e); } finally { if (conn != null) { conn.disconnect(); } } } 

But I get:

 08:56:31,813 ERROR [VarnishHandler] Could not call varnish: java.net.ProtocolException: Invalid HTTP method: PURGE 

There are no problems with curl:

curl -I -X PURGE -H "Host: www.somehost.com" someurl

 HTTP/1.1 404 Not in cache. Server: Varnish Content-Type: text/html; charset=utf-8 Retry-After: 5 Content-Length: 401 Accept-Ranges: bytes Date: Thu, 18 Oct 2012 06:40:19 GMT X-Varnish: 1611365598 Age: 0 Via: 1.1 varnish Connection: close X-Cache: MISS 

So how do I do this? Do I need to curl up with Java, or is there some other library that I can use?

Answer 1

You can use the Apache HttpClient library: http://hc.apache.org/httpcomponents-client-ga/

You can use BasicHttpRequest or implement your own HttpPurge class that extends HttpRequestBase .

You can find the quick start guide here: http://hc.apache.org/httpcomponents-client-ga/quickstart.html

Example:

 DefaultHttpClient httpclient = new DefaultHttpClient(); BasicHttpRequest httpPurge = new BasicHttpRequest("PURGE", "www.somehost.com") HttpResponse response = httpclient.execute(httpPurge); 

Answer 2

As of org.apache.httpcomponents 4.2.1:

Grade:

 import org.apache.http.client.methods.HttpRequestBase; import java.net.URI; public class HttpPurge extends HttpRequestBase { public final static String METHOD_NAME = "PURGE"; public HttpPurge() { super(); } @Override public String getMethod() { return METHOD_NAME; //To change body of implemented methods use File | Settings | File Templates. } public HttpPurge(final String uri) { super(); setURI(URI.create(uri)); } public String getName() { return "PURGE"; } } 

Call:

 import org.apache.http.Header; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.message.BasicHeader; import org.apache.http.util.EntityUtils; import test.HttpPurge private void callVarnish(URL url) { DefaultHttpClient httpclient = new DefaultHttpClient(); HttpPurge httpPurge = new HttpPurge(url.toString()); Header header = new BasicHeader("Host", "www.somewhere.se"); httpPurge.setHeader(header); try { HttpResponse response = httpclient.execute(httpPurge); System.out.print("-------------------------------------"); System.out.println(response.getStatusLine()); System.out.print("-------------------------------------"); HttpEntity entity = response.getEntity(); // If the response does not enclose an entity, there is no need // to worry about connection release if (entity != null) { // do something useful with the response body // and ensure it is fully consumed EntityUtils.consume(entity); } } catch (IOException ex) { // In case of an IOException the connection will be released // back to the connection manager automatically } catch (RuntimeException ex) { // In case of an unexpected exception you may want to abort // the HTTP request in order to shut down the underlying // connection and release it back to the connection manager. httpPurge.abort(); } } 

With deprecated org.apache.commons.httpclient.HttpMethodBase:

Grade:

 import org.apache.commons.httpclient.HttpMethodBase; public class PurgeMethod extends HttpMethodBase { public PurgeMethod() { super(); setFollowRedirects(true); } public PurgeMethod(String url) { super(url); setFollowRedirects(true); } public String getName() { return "PURGE"; } } 

Call:

 import org.apache.commons.httpclient.Header; import org.apache.commons.httpclient.HttpClient; import org.apache.commons.httpclient.HttpMethod; private void callVarnish(URL url) { HttpClient client = new HttpClient(); HttpMethod method = new PurgeMethod(url.toString()); try { int status = 0; status = client.executeMethod(method); log.debug(status); } catch (Exception e) { // something } finally { method.releaseConnection(); } 

}

Answer 3

With the HttpComponents API has changed. The current version of uldall's answer is as follows:

 HttpHost host = new HttpHost(hostname, port); HttpClient httpclient = HttpClientBuilder.create().build(); BasicHttpRequest purgeRequest = new BasicHttpRequest("PURGE", "/some/url"); HttpResponse response = httpclient.execute(host, purgeRequest);