import java.io.*;
import java.net.*;

/**
 * A client to retrieve a web page using the URL package, instead
 * of raw socket. <p>
 * 
 * @author Xiannong Meng
 * @date   September 8, 2004
 *         Revised  February 4, 2005
 *
 */
public class URLClient  {

    final static int MAXBUF = 4096;  // max num of chars read one time

   public static void main(String argv[]) throws Exception  {

       if (argv.length != 1) {
	   System.err.println("usage : java URLClient url");
	   System.exit(1);
       }
       
       String content = readAPage(argv[0]);
       System.out.println(content);
   }

    // read a web page
    static public String readAPage(String urlStr)  {

	HttpURLConnection uC = null;
	int responseCode = -1;
	InputStream input;
	BufferedReader remote;
	String strBuffer = "";
	
	if (Crawler.DEBUG == true)
	    System.err.println("url:" + urlStr);
	try {
	    // urlStr is in the form "http://www.yahoo.com/" 
	    URL u = new URL(urlStr);  

	   // connet to the site
	   uC = (HttpURLConnection)u.openConnection(); 
	   //	   System.out.println("port " + u.getPort());
	   responseCode = uC.getResponseCode();
       } catch (Exception ex)  {
	   System.err.println("first : " + ex.getMessage());
       }

       if (responseCode != HttpURLConnection.HTTP_OK)  {
	   System.err.println(("HTTP response code : " + 
			       String.valueOf(responseCode)));
       }
       
       try {
	   input = uC.getInputStream();
	   remote = new BufferedReader(new InputStreamReader(input));

	   strBuffer = readPage(remote);
	   //	   System.out.println(strBuffer);
      }
      catch (Exception ex) {
	 System.err.println(ex.getMessage());
      }
       /**
      System.out.println(" host : " + u.getHost());
      System.out.println(" protocol : " + u.getProtocol());
      System.out.println(" port : " + u.getPort());
      System.out.println(" allow interaction : " + uC.getAllowUserInteraction());
      System.out.println(" allow interaction default : " + uC.getDefaultAllowUserInteraction());

      System.out.println("URL : " + uC.getURL());
      System.out.println("header : " + uC.getHeaderField("http"));
       **/

       return strBuffer;
   }

    // given a BufferedReader created from a URL, read the whole page
    static String readPage(BufferedReader inReader) 
	throws IOException   {

	String strBuffer = "";
	char[] data = new char[MAXBUF];
	int charRead = inReader.read(data, 0, MAXBUF);
	while (charRead > 0) {
	    String localStr = new String(data, 0, charRead);
	    strBuffer += localStr;
	    charRead = inReader.read(data, 0, MAXBUF);
	}

	return strBuffer;
    }

}