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106

Chapter 4 Handling the Client Request: HTTP Request Headers

Listing 4.2 EncodedPage.java 

package coreservlets;

import java.io.*;

import javax.servlet.*;

import javax.servlet.http.*;

import java.util.zip.*;

/** Example showing benefits of gzipping pages to browsers

 *  that can handle gzip.

*/

public class EncodedPage extends HttpServlet {

  public void doGet(HttpServletRequest request,

                    HttpServletResponse response)

      throws ServletException, IOException {

    response.setContentType("text/html");

    String encodings = request.getHeader("Accept Encoding");

    String encodeFlag = request.getParameter("encoding");

    PrintWriter out;

    String title;

    if ((encodings != null) &&

        (encodings.indexOf("gzip") !=  1) &&

        !"none".equals(encodeFlag)) {

      title = "Page Encoded with GZip";

      OutputStream out1 = response.getOutputStream();

      out = new PrintWriter(new GZIPOutputStream(out1), false);

      response.setHeader("Content Encoding", "gzip");

    } else {

      title = "Unencoded Page";

      out = response.getWriter();

    }

    out.println(ServletUtilities.headWithTitle(title) +

                "\n" +

                "
" + title + "
\n");

    String line = "Blah, blah, blah, blah, blah. " +

                  "Yadda, yadda, yadda, yadda.";

    for(int i=0; i<10000; i++) {

      out.println(line);

    }

    out.println("");

    out.close();

  }

}

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