Question

I am working to change the HTTP client in an application from Commons HTTP Client v3.x to the new HTTP Client v4.x. I searched but could not find good examples for the following scenarios– can you point me to a good tutorial/article on the new HTTP Client (something similar to the excellent Community Wiki article at SO on java.net.url)?

(1) set Cookie Policy

(2) set Http Proxy- defining host/domain as well as username/password

Currently this is done in the following manner–

Credentials credentials =
            ( host == null || domain == null || "".equals(host.trim()) ||     
           "".equals(domain.trim()) ) ?
                new UsernamePasswordCredentials(username, password) :
                new NTCredentials(username, password, host, domain);

 client.getState().setProxyCredentials( AuthScope.ANY, credentials);

(3) Auth credentials are defined in the old http client with the following code–

  client.getState().setCredentials(
                new AuthScope(urlObj.getHost(), urlObj.getPort()),
                new UsernamePasswordCredentials(username, password)
            );

What is the way to do this in the new HTTP client?

(4) Declaring a new HTTP Method variable and for this variable, Specifying method- as GET or POST

Code used for the above currently–

 HttpMethodBase method;
method = createPostMethod(url, params, multipart, charset);
 method = createGetMethod(url, params, charset);

(5) Adding request headers to a method –

For example, to set the user agent as Default user agent, the following code is used–

method.addRequestHeader(new Header("User-Agent", DEFAULT_USER_AGENT));

Answer 1

(1)cookie thing see this from another question

(2)Proxy:

httpclient.getCredentialsProvider().setCredentials(
                    new AuthScope("localhost", 8080),
                    new UsernamePasswordCredentials("username", "password"));

HttpHost targetHost = new HttpHost("www.verisign.com", 443, "https");
HttpHost proxy = new HttpHost("localhost", 8080);

httpclient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy);

HttpGet httpget = new HttpGet("/");

from:

httpcomponents-client-4.1.3\examples\org\apache\http\examples\client\ClientProxyAuthentication.java

(3)Not sure

(4)Method

HttpGet httpget = new HttpGet(url);
HttpPost httpost = new HttpPost("https://portal.sun.com/amserver/UI/Login?" +
                    "org=self_registered_users&" +
                    "goto=/portal/dt&" +
                    "gotoOnFail=/portal/dt?error=true");

From ClientFormLogin.java of example

(5)header field:

HttpGet get = new HttpGet(url);
get.setHeader("Content-Type", "text/html");
get.setHeader("User-Agent","Mozilla/4.0 (MobilePhone SCP-5500/US/1.0) NetFront/3.0 MMP/2.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)");
get.setHeader("Accept-Charset", Chareset+";q=0.7,*;q=0.7");//"utf-8;q=0.7,*;q=0.7");
get.getParams().setParameter("http.socket.timeout",20000);

How about that?
Just see the examples.