Alternative Java Clients - RESTful Java with JAX-RS 2.0 - page 249

tpPost.setEntity() . Since we are expecting a redirection header with our response and we
do not want to be automatically redirected, we must configure the request to not do automat-
ic redirects. We do this by calling HttpClientParams.setRedirection() . We execute the
request the same way we did with our GET example. We get the Location header by calling
HttpResponse.getLastHeader() .

Authentication

The Apache HttpClient 4.x supports Basic, Digest, and Client Certificate Authentication.
Basic and Digest Authentication are done through the DefaultHttpCli-
ent.getCredentialsProvider().setCredentials() method. Here's an example:

DefaultHttpClient client = new new DefaultHttpClient ();

client . getCredentialsProvider (). setCredentials (
new

new AuthScope ( "example.com" , 443 ),
new

new UsernamePasswordCredentials ( "bill" , "geheim" );

);

The org.apache.http.auth.AuthScope class defines the server and port that you want to
associate with a username and password. The
org.apache.http.auth.UsernamePasswordCredentials class encapsulates the username
and password into an object. You can call setCredentials() for every domain you need to
communicate with securely.
Apache HttpClient, by default, does not do preemptive authentication for the Basic and Di-
gest protocols, but does support it. Since the code to do this is a bit verbose, we won't cover
it in this topic.

Client Certificate authentication

Apache HttpClient also supports Client Certificate Authentication. As with HttpsURLCon-
nection , you have to load in a KeyStore that contains your client certificates. The section
java.net.URL describes how to do this. You initialize an
org.apache.http.conn.ssl.SSLSocketFactory with a loaded KeyStore and associate it
with the DefaultHttpClient . Here is an example of doing this:

import import java.io.File java.io.File ;

import import java.io.FileInputStream java.io.FileInputStream ;

import import java.security.KeyStore java.security.KeyStore ;

import import org.apache.http.* org.apache.http.* ;

import import org.apache.http.HttpResponse org.apache.http.HttpResponse ;

import import org.apache.http.client.methods.* org.apache.http.client.methods.* ;