Problem with Apache DefaultHttpClient class

Computer: Software & Programmierung Java
#1

Hello!

I am a newbie for servlet applications, trying to learn the subject. On my way, I wrote a servlet class called FormWebServlet that uses the org.apache.http.impl.client.DefaultHttpClient class. However, I get the exception

java.lang.ClassNotFoundException: org.apache.http.impl.client.DefaultHttpClient

… that clearly shows that this class does not exist, although I have added the jar file to the project.

The server returns an „HTTP Status 500“ error with the message that the „root cause“ is this missing class:

java.lang.NoClassDefFoundError: org/apache/http/impl/client/DefaultHttpClient
testPackage.FormWebServlet.doGet(FormWebServlet.java:45)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)

TRIES

  1. I searched for the missing jar file and added it to the project (by going on the project in „Eclipse JAVA EE IDE for Web Developers, 20100917-0705“'s project explorer, select „Properties“, selected the „Java Build Path“ and clicked the [Add External JARs…] button.) The added jar file is from the Apache site and is called httpclient-4.1.1.jar.
  2. As I still get the same error, I extracted with 7-ZIP the DefaultHttpClient.class file and put it into the WebContent/WEB-INF/lib directory.

QUESTION
What am I doing wrong?

DETAILS
Inculded JARs:
common-httpclient-3.0.1.jar
httpclient-4.1.1.jar
httpcore-4.1.jar

FormWebServlet.jar:
/**
*
*/
package testPackage;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import coreServlets.ServletUtilities;

/**
*
*/
@WebServlet(description = „Gets the book’s barcode with a form“, urlPatterns = { „/FormWebServlet“ })
public class FormWebServlet extends HttpServlet {

/** */
private static final long serialVersionUID = 6008315960327824633L;

/**
* @see HttpServlet#doGet(HttpServletRequest request,
* HttpServletResponse response)
*/
protected void doGet(final HttpServletRequest request,
final HttpServletResponse response)
throws IOException, ServletException {
final String BAR_CODE = request.getParameter(„barCode“);

response.setContentType(„text/html“);
final PrintWriter out = response.getWriter();

if (BAR_CODE != null) {
HttpClient client = new DefaultHttpClient();
final String ADDRESS = ServletUtilities.getHttpAddress(BAR_CODE);

out.println(„ADDRESS = „“ + ADDRESS + '“’);
HttpGet get = new HttpGet(ADDRESS);

HttpResponse httpResponse = null;

// Removed commented code that will use these objects
}
}
}