BE THE CODER > Tools and Libs > Commons Http Client > Basic Preemptive Authentication2

Commons Http Client is a HTTP agent implementation in java supporting client-side authentication, HTTP state management and HTTP connection management. This requires the libraries httpclient-4.1.2.jar, httpcore-4.1.2.jar, httpmime-4.1.2.jar, httpclient-cache-4.1.2.jar, commons-codec.jar and commons-logging-1.1.1.jar to be in classpath. The following example shows how to access a JSP page protected through basic authentication in Tomcat v6.0.

Configure a new tomcat user venakat and role btc in tomcat-users.xml as shown below,

File Name :

/HTTP_TEST_APP/tomcat_config_files/tomcat-users.xml

File Name :

/HTTP_TEST_APP/tomcat_config_files/basic_auth_web.xml

File Name :

/HTTP_TEST_APP/WebContent/basic_protected.jsp

A simple Http Client to access the protected JSP. We can see that the basic authentiction information is passed as request header in the format Authorization : Basic Base64(username:password)

File Name :	com/bethecoder/tutorials/commons_httpclient/BasicPreemptiveAuthenticationTest2.java
Author :	Sudhakar KV
Email :	[email protected]


package com.bethecoder.tutorials.commons_httpclient;



import java.io.IOException;



import org.apache.http.HttpHost;

import org.apache.http.auth.AuthScope;

import org.apache.http.auth.UsernamePasswordCredentials;

import org.apache.http.client.AuthCache;

import org.apache.http.client.ClientProtocolException;

import org.apache.http.client.ResponseHandler;

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

import org.apache.http.client.protocol.ClientContext;

import org.apache.http.impl.auth.BasicScheme;

import org.apache.http.impl.client.BasicAuthCache;

import org.apache.http.impl.client.BasicResponseHandler;

import org.apache.http.impl.client.DefaultHttpClient;

import org.apache.http.protocol.BasicHttpContext;



public class BasicPreemptiveAuthenticationTest2 {



  /**

   * @param args

   * @throws IOException 

   * @throws ClientProtocolException 

   */

  public static void main(String[] args) throws ClientProtocolException, IOException {

    

    DefaultHttpClient httpclient = new DefaultHttpClient();

    HttpHost targetHost = new HttpHost("localhost", 8080);

    HttpGet httpget = new HttpGet("http://localhost:8080/HTTP_TEST_APP/basic_protected.jsp");

    System.out.println("Requesting : " + httpget.getURI());



    try {

      UsernamePasswordCredentials credentials = new UsernamePasswordCredentials("venkat", "mypassword");

      AuthScope authscope = new AuthScope(targetHost.getHostName(), targetHost.getPort());

      httpclient.getCredentialsProvider().setCredentials(authscope, credentials);



      //Create Authentication Cache

            AuthCache authCache = new BasicAuthCache();

            authCache.put(targetHost, new BasicScheme());

            

            //Add AuthCache to the execution context

            BasicHttpContext localcontext = new BasicHttpContext();

            localcontext.setAttribute(ClientContext.AUTH_CACHE, authCache);



            for (int i = 0 ; i < 2 ; i ++) {

        ResponseHandler<String> responseHandler = new BasicResponseHandler();

              String responseBody = httpclient.execute(targetHost, httpget, responseHandler, localcontext);

        System.out.println("\n=========== RESPONSE ======== " + responseBody);

            }

      

    } finally {

       httpclient.getConnectionManager().shutdown();

    }



  }



}