Android : oauth.signpost.commonshttp.CommonsHttpOAuthProvider', referenced from method com.oDesk.api.OAuthClient?

When I integrating the odesk api in my android app I got this error.

09-15 05:22:21.459: E/dalvikvm(6387): Could not find class 'oauth.signpost.commonshttp.CommonsHttpOAuthProvider', referenced from method com.oDesk.api.OAuthClient.<clinit>
09-15 05:22:21.459: W/dalvikvm(6387): VFY: unable to resolve new-instance 1356 (Loauth/signpost/commonshttp/CommonsHttpOAuthProvider;) in Lcom/oDesk/api/OAuthClient;
09-15 05:22:21.459: D/dalvikvm(6387): VFY: replacing opcode 0x22 at 0x0003
09-15 05:22:21.469: E/dalvikvm(6387): Could not find class 'oauth.signpost.commonshttp.CommonsHttpOAuthConsumer', referenced from method com.oDesk.api.OAuthClient.<init>
09-15 05:22:21.469: W/dalvikvm(6387): VFY: unable to resolve new-instance 1355 (Loauth/signpost/commonshttp/CommonsHttpOAuthConsumer;) in Lcom/oDesk/api/OAuthClient;
09-15 05:22:21.479: D/dalvikvm(6387): VFY: replacing opcode 0x22 at 0x001b
09-15 05:22:21.479: E/dalvikvm(6387): Could not find class 'org.apache.http.client.utils.URIBuilder', referenced from method com.oDesk.api.OAuthClient.sendGetRequest
09-15 05:22:21.479: W/dalvikvm(6387): VFY: unable to resolve new-instance 1384 (Lorg/apache/http/client/utils/URIBuilder;) in Lcom/oDesk/api/OAuthClient;

And here is my code:

if (client == null) {
   //NOTE: KEY/SECRET PAIR MUST BE STORED IN A SAFE PLACE
   //THIS PART OF ASSIGNING OF CONSUMER KEY IS AN EXAMPLE
   Properties props = new Properties();
   props.setProperty("consumerKey", ODESK_CONSUMER_KEY);
   props.setProperty("consumerSecret", ODESK_CONSUMER_SECRET);

   Config config = new Config(props);

   //OAuthClient client1  =    new OAuthClient(config);

   client = new OAuthClient(config);
   }
   // authorize
new ODeskAuthorizeTask().execute();

The problem here is when debug the app is crash in the line client = new OAuthClient(config); can I get any solutions for this.

I added all the jars files.