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7.4 Using Persistent HTTP Connections

167

Listing 7.7  ImageRetriever.java (continued)

      while((imageByte = in.read()) !=  1) {

        byteStream.write(imageByte);

      }

      in.close();

      String persistenceFlag =

      request.getParameter("usePersistence");

      boolean usePersistence =

        ((persistenceFlag == null) ||

         (!persistenceFlag.equals("no")));

      response.setContentType("image/gif");

      if (usePersistence) {

        response.setContentLength(byteStream.size());

      } 

      byteStream.writeTo(response.getOutputStream());

    } catch(IOException ioe) {

      reportError(response, "Error: " + ioe);

    }

  }

  public void reportError(HttpServletResponse response,

                          String message)

      throws IOException {

    response.sendError(response.SC_NOT_FOUND,

                       message);

  }

}

Figure 7 4

Result of the PersistentConnection servlet.

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