URLConnection != Sockets

Question

I am writing a servlet that reads content from some URLs, and uses regular expressions to get data from these URLs.
When I use URLConnection, everything goes ok, but when I use Sockets, in some URLs, I can't extract the data from it using regular expressions, because the data from the URLConnection sometimes differ from the data from the sockets. And sometimes I get unexpected results, like:
HTTP/1.1 302 Moved TemporarilyServer: Netscape-Enterprise/4.1Date: Fri, 28 Dec 2001 04:35:22 GMTLocation: http://www.uol.com.br/Content-length: 0Content-type: text/htmlConnection: close
What can I do to fix my code? Here is the code I am using:
USING SOCKETS::
import java.net.*;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class testurl extends HttpServlet {
  public void doGet(HttpServletRequest request,
                    HttpServletResponse response)
  throws IOException, ServletException
   response.setContentType("text/html");
   PrintWriter out = response.getWriter();
BufferedReader data;
String line;
StringBuffer buf = new StringBuffer();
URL url;
Socket httpSocket;
String tmp1 = "";
try {
url = new URL("http://www2.uol.com.br/cgi-bin/AT-examesearch.cgi?search=test");
httpSocket = new Socket(url.getHost(),url.getPort()==-1?80:url.getPort());
httpSocket.setSoTimeout(45000);
new DataOutputStream(httpSocket.getOutputStream()).writeBytes("GET " + url.getFile() + " HTTP/1.0\r\n\r\n");
data = new BufferedReader(new InputStreamReader(httpSocket.getInputStream()));
while ((line = data.readLine()) != null) {
  buf.append(line);
tmp1 = buf.toString();
data.close();
catch(MalformedURLException mue){
catch (UnknownHostException uhe){
catch (InterruptedIOException ioe){
catch (IOException ioe){
out.println(tmp1);
  public void doPost(HttpServletRequest request,
                     HttpServletResponse response)
  throws IOException, ServletException
        doGet(request, response);
}USING URLCONNECTION::
      URLConnection conn = null;
      BufferedReader data;
      String line;
      StringBuffer buf = new StringBuffer();
      try {
        conn = new URL("http://www2.uol.com.br/cgi-bin/AT-examesearch.cgi?search=test").openConnection();
        conn.connect();
        data = new BufferedReader(new InputStreamReader(conn.getInputStream()));
        while ((line = data.readLine()) != null) {
          buf.append(line);
        tmp1 = buf.toString();
        data.close();
      } catch(MalformedURLException e) {
      } catch(IOException e) { }     
.

Answer 1

1. HttpUrlConnection sends header information to identify user-agent (Java <version>) and formats understood ("text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2") and makes HTTP/1.1 requests; you don't.
2. It is aware of and handles redirects by default (controlled via the set/getFollowRedirects accessors), you don't.
HTTP requires more than just connecting to port 80.