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JAva-based Survey Servlet help comes with my code

I have written a short code about a simple survey servlet that submits results. My question or favor is, can someone help me develop some code on how I can allow a user to view the results of the survey without responding to the survey?

Here is my code:

// A Web-based survey that uses JDBC from a servlet.

import java.io.PrintWriter;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.UnavailableException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class SurveyServlet extends HttpServlet
{
private Connection connection;
private Statement statement;

// set up database connection and create SQL statement
public void init( ServletConfig config ) throws ServletException
{
// attempt database connection and create Statement
try
{
Class.forName( config.getInitParameter( "databaseDriver" ) );
connection = DriverManager.getConnection(
config.getInitParameter( "databaseName" ),
config.getInitParameter( "username" ),
config.getInitParameter( "password" ) );

// create Statement to query database
statement = connection.createStatement();
} // end try
// for any exception throw an UnavailableException to
// indicate that the servlet is not currently available
catch ( Exception exception )
{
exception.printStackTrace();
throw new UnavailableException( exception.getMessage() );
} // end catch
} // end method init

// process survey response
protected void doPost( HttpServletRequest request,
HttpServletResponse response )
throws ServletException, IOException
{
// set up response to client
response.setContentType( "text/html" );
PrintWriter out = response.getWriter();

// start XHTML document
out.println( "<?xml version = \"1.0\"?>" );

out.printf( "%s%s%s", "<!DOCTYPE html PUBLIC",
" \"-//W3C//DTD XHTML 1.0 Strict//EN\"",
" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\">\n" );

out.println(
"<html xmlns = \"http://www.w3.org/1999/xhtml\">" );

// head section of document
out.println( "<head>" );

// read current survey response
int value =
Integer.parseInt( request.getParameter( "animal" ) );
String sql;

// attempt to process a vote and display current results
try
{
// update total for current survey response
sql = "UPDATE surveyresults SET votes = votes + 1 " +
"WHERE id = " + value;
statement.executeUpdate( sql );

// get total of all survey responses
sql = "SELECT sum( votes ) FROM surveyresults";
ResultSet totalRS = statement.executeQuery( sql );
totalRS.next(); // position to first record
int total = totalRS.getInt( 1 );

// get results
sql = "SELECT surveyoption, votes, id FROM surveyresults " +
"ORDER BY id";
ResultSet resultsRS = statement.executeQuery( sql );
out.println( "<title>Thank you!</title>" );
out.println( "</head>" );

out.println( "<body>" );
out.println( "Thank you for participating." );
out.println( " Results:<pre>" );

// process results
int votes;

while ( resultsRS.next() )
{
out.print( resultsRS.getString( 1 ) );
out.print( ": " );
votes = resultsRS.getInt( 2 );
out.printf( "%.2f", ( double ) votes / total * 100 );
out.print( "% responses: " );
out.println( votes );
} // end while

resultsRS.close();

out.print( "Total responses: " );
out.print( total );

// end XHTML document
out.println( "</pre></body></html>" );
out.close();
} // end try
// if database exception occurs, return error page
catch ( SQLException sqlException )
{
sqlException.printStackTrace();
out.println( "<title>Error</title>" );
out.println( "</head>" );
out.println( "<body>Database error occurred. " );
out.println( "Try again later.</body></html>" );
out.close();
} // end catch
} // end method doPost

// close SQL statements and database when servlet terminates
public void destroy()
{
// attempt to close statements and database connection
try
{
statement.close();
connection.close();
} // end try
// handle database exceptions by returning error to client
catch( SQLException sqlException )
{
sqlException.printStackTrace();
} // end catch
} // end method destroy
} // end class SurveyServlet

ASKER CERTIFIED SOLUTION

Lucky48390

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