How can I override the "Host" header in the request when using Apache commons HttpClient

Question

I am using Jakarta Commons HttpClient 3.1 writing a load test tool that needs to target different servers and pretend like it targeted the correct virtual host in the HTTP server. For that I need to be able to set the "Host" HTTP header in the request to a different host name then the actual host name that I'm connecting to.

It seemed pretty obvious that I should use Method.setRequestHeader("Host","fakehostname"), but HttpClient just ignores this and always sends the real host name I'm connecting to in the "Host" header (I've enabled debug logging for "httpclient.wire" and I can it does this specifically).

How can I override the header so that HttpClient takes heed?

Answer 1

I believe you want http://hc.apache.org/httpcomponents-core-ga/httpcore/apidocs/org/apache/http/HttpHost.html: this lets you configure the host for a specific connection. If I understand it correctly, you can either use the execute method (see http://hc.apache.org/httpcomponents-client-ga/httpclient/apidocs/org/apache/http/impl/client/AbstractHttpClient.html#execute(org.apache.http.HttpHost,%20org.apache.http.HttpRequest)) and pass it a custom HttpHost object, or do this:

1. Construct an HttpHost instance, passing it your Host header.
2. Use that to create an HttpRoute instance (see http://hc.apache.org/httpcomponents-client-ga/httpclient/apidocs/org/apache/http/conn/routing/HttpRoute.html)
3. Pass that to the connection manager when you request a connection (see http://hc.apache.org/httpcomponents-client-ga/httpclient/apidocs/org/apache/http/conn/ClientConnectionManager.html#requestConnection(org.apache.http.conn.routing.HttpRoute,%20java.lang.Object)).
4. Use the connection with your method: see http://hc.apache.org/httpcomponents-client-ga/tutorial/html/connmgmt.html for more details.

Let me know how that works.

EDIT: principle remains the same. 1. Construct an HttpHost instance, passing it your Host header (see http://hc.apache.org/httpclient-legacy/apidocs/index.html?org/apache/commons/httpclient/HttpHost.html). 2. Create an HttpConfiguration instance and then pass it the HttpHost you created (see http://hc.apache.org/httpclient-legacy/apidocs/index.html?org/apache/commons/httpclient/HostConfiguration.html). 3. Use the execute method on HttpClient with that configuration (see http://hc.apache.org/httpclient-legacy/apidocs/org/apache/commons/httpclient/HttpClient.html#executeMethod(org.apache.commons.httpclient.HostConfiguration,%20org.apache.commons.httpclient.HttpMethod))