Help with displaying results from a resultset

Why would you use an applet if you can use a JSP instead ?
You already have the servlet, so the JSP seems to be the next step.
Here's a piece of code out of one of my JSP's :
<DIV id=scroll1 style="BORDER:2px; OVERFLOW: auto; position: absolute; width: 700px; height: 250px; visibility: visible; left: 157px; top: 317px;">

<table width="600" border="0" align="center" id="lijst">

<%
for (Iterator i = filmLijst.iterator(); i.hasNext(); )
{
Film film = (Film) i.next();
%>

<tr>
<td width="80"><input name="detail" type="submit" id="detail" value="<%=film.getFilmnummer()%>"></td>
<td width="274"><%=film.getTitel()%> </td>
<td width="113"><%=film.getJaaruitgave()%></td>
<td width="115"><%=film.getGenre()%></td>
</tr>
<% } %>
</table>

</DIV>

If you want more information about how this works, let me know. I'll get more into detail of working with a JSP seems to you as a good idea

Hi i m Rashmi will u pls tell me how to display records searched from access database into JTable can u pls send me some coding
Thanks
Rashmi Pant

The model is composed of all the javabeans you need. This model corresponds to the business layer in the 3 layer-model.
Every Javabeans is composed of properties and methods. The methods can be divided into 3 different types :
- the constructor : used to create an object of this type of class
- the getter : used to show the value of a certain property
- the setter : used to note the value in a certain property.

The advantage of using getters and setters is that an object of the class is always responsible for its values. With the setter, the class can controll the values it is supposed to write down in its property. And in certain cases, the class
can refuse to write down an illegal value. The same goes for the getters : the class can decide to show the value in a certain format.

One of my javabeans is called film.java. Here's the code.
Some words are written in dutch; this helps me to know whether a
method is included in the java SDK or is one of my own.

package org.gertcuppens.cluif;

/* import java.util */
import java.util.Calendar;
import java.util.ArrayList;

/*import java .sql */
import java.sql.Blob;
import java.sql.Time;
import java.sql.ResultSet;
import java.sql.SQLException;

//import org.w3c.dom.Text;

/**
* @author GC1494
*
* Film verwijst naar een film uitgebracht in de cinema of op TV.
*/

public class Film {

private int filmnummer;
private String titel;
private short jaaruitgave;
private String genre;
private Calendar duurtijd;
private String taal;
private Blob poster;
private String korteInhoud;
private String inhoud;
private ArrayList filmPloeg;
private ArrayList rollenLijst;




public Film ()
{
this.setFilmnummer(0);
this.setTitel("");
this.setGenre("");

}

public Film (ResultSet _rs, String soort)
throws SQLException
{
if (soort.equals("lijst"))
{
this.setFilmnummer(_rs.getInt("filmnummer"));
this.setTitel(_rs.getString("titel"));
this.setJaaruitgave(_rs.getShort("jaarUitgave"));
this.setGenre(_rs.getString("genre"));

} /* soort == lijst */
else {
this.setFilmnummer(_rs.getInt("filmnummer"));
this.setTitel(_rs.getString("titel"));
this.setJaaruitgave(_rs.getShort("jaarUitgave"));
this.setGenre(_rs.getString("genre"));
this.setKorteInhoud(_rs.getString("korteInhoud"));
this.setInhoud(_rs.getString("inhoud"));
this.setDuurtijd(_rs.getTime("duurtijd"));

}

}

public String getFilmnummer() {
Integer filmnummerInt = new Integer(this.filmnummer);
String filmnummerStr = filmnummerInt.toString();
StringBuffer filmnummerBuffer = new StringBuffer();
switch (filmnummerStr.length())
{
case 1 : filmnummerBuffer.append("000");
filmnummerBuffer.append(filmnummerStr);
break;
case 2 : filmnummerBuffer.append("00");
filmnummerBuffer.append(filmnummerStr);
break;
case 3 : filmnummerBuffer.append("0");
filmnummerBuffer.append(filmnummerStr);
break;
default : filmnummerBuffer.append(filmnummerStr);
break;

} /* switch */


return filmnummerBuffer.toString();
}

/**
*
* @uml.property name="titel"
*/
public String getTitel() {
return titel;
}

/**
*
* @uml.property name="jaaruitgave"
*/
public String getJaaruitgave() {
if (this.jaaruitgave == 0)
{
return ("onbekend");
}
else
{
return (String.valueOf(this.jaaruitgave));

}

}

/**
*
* @uml.property name="genre"
*/
public String getGenre() {
if (genre == null)
{
return("onbekend");
}
else
return genre;
}

/**
*
* @uml.property name="duurtijd"
*/
public String getDuurtijd() {
int uur;
int minuten;
String uurStr, minutenStr, deel1;

if (duurtijd != null)
{
uur = duurtijd.get(10); // 10 == HOUR
minuten = duurtijd.get(12); // 12 == MINUTE
uurStr = String.valueOf(uur);
minutenStr = String.valueOf(minuten);
deel1 = uurStr.concat(":");
System.out.println("uur is" + uurStr);
System.out.println("minuten is " + minutenStr);
return (deel1.concat(minutenStr));
}
else
return "00:00" ;
}

/**
*
* @uml.property name="taal"
*/
public String getTaal() {
return taal;
}

/**
*
* @uml.property name="poster"
*/
public Blob getPoster() {
return poster;
}

public String getKorteInhoud() {
if (this.korteInhoud != null)
return korteInhoud;
else
return "";
}

/**
*
* @uml.property name="Inhoud"
*/
public String getInhoud() {
if (this.inhoud != null)
return inhoud;
else
return "";
}

public ArrayList getFilmPloeg ()
{
return this.filmPloeg;
}

public ArrayList getRollenLijst ()
{
return this.rollenLijst;
}


/**
*
* @uml.property name="filmnummer"
*/
public void setFilmnummer(int _filmnummer) {
this.filmnummer = _filmnummer;
}

/**
*
* @uml.property name="titel"
*/
public void setTitel(String _titel) {
this.titel = _titel;
}

/**
*
* @uml.property name="jaaruitgave"
*/
public void setJaaruitgave(short _jaaruitgave) {
this.jaaruitgave = _jaaruitgave;
}

/**
*
* @uml.property name="genre"
*/
public void setGenre(String _genre) {
this.genre = _genre;
}

/**
*
* @uml.property name="duurtijd"
*/
public void setDuurtijd(Time _duurtijd) {
Calendar duurtijdCal = Calendar.getInstance();
if (_duurtijd != null)
duurtijdCal.setTimeInMillis(_duurtijd.getTime());
this.duurtijd = duurtijdCal;
// gevonden op java.sun.com
// Time t = rs.getTime("time");
// Calendar cal = Calendar.getInstance();
// cal.setTimeInMillis(t.getTime());
}

/**
*
* @uml.property name="taal"
*/
public void setTaal(String _taal) {
this.taal = _taal;
}

/**
*
* @uml.property name="poster"
*/
public void setPoster(Blob _poster) {
this.poster = _poster;
}

public void setKorteInhoud(String _korteInhoud) {
this.korteInhoud = _korteInhoud;
}

/**
*
* @uml.property name="korteInhoud"
*/
public void setInhoud(String _inhoud) {
this.inhoud = _inhoud;
}

public void setFilmPloeg (ArrayList _filmPloeg)
{
this.filmPloeg = _filmPloeg;
}

public void setRollenLijst (ArrayList _rollenLijst)
{
this.rollenLijst = _rollenLijst;
}



}

Now that you have the abstract class GeneralDao, you can write any DAO you need.
Each DAO will need to inherit from the GeneralDao like this :
public class FilmDao extends GeneralDao {

Below, you will find the code of my FilmDao class
Whenever you see the class Melding in the code, this class is used for catching exceptions.
Melding is dutch for message, but I've got the habit of giving my classes dutch names.
That way, I know right away whether I've written the class or whether it's a class from Java or another provider.

package org.gertcuppens.cluifDao;

/*import java.sql */
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Blob;

import java.util.ArrayList;
// import java.util.Collection;

/* import org.apache.log4j */
import org.apache.log4j.Logger;

/* import org.gertcuppens.* */
import org.gertcuppens.cluif.Film;
import org.gertcuppens.cluif.FilmMedewerker;
import org.gertcuppens.algemeen.Melding;

/**
* @author GC1494
*
* De GeneralDao definieert nmaal de getConnection() methode om connectie met de databank te leggen.
* Alle DAO's erven van deze GeneralDao.
*/

public class FilmDao extends GeneralDao {

public ArrayList zoekFilmOpLetter(String _letter)
throws Melding
{
ArrayList filmLijst = new ArrayList();
Connection con = null;
PreparedStatement ps = null;
ResultSet rs = null;
try {
StringBuffer zoekString = new StringBuffer();
zoekString.append("select * from film ");
zoekString.append("where titel like '" + _letter + "%'");
System.out.println("zoekstring heeft de waarde " + zoekString);
con = getDatabaseConnection();
ps = con.prepareStatement(zoekString.toString());
rs = ps.executeQuery();

if (rs == null)
{
ps.close();
con.close();
System.out.println("geen film gevonden");
}
else
{
while (rs.next() )
{
Film film = new Film (rs, "lijst");
System.out.println("gevonden film is " + film.getTitel());
filmLijst.add(film);

} /* while rs.next() */
rs.close();
ps.close();
con.close();
} /* else : rs != null */

} catch (SQLException sqlEx)
{
Melding melding = new Melding(sqlEx);
throw melding;
}
catch (Melding melding)
{
throw melding;
}

return filmLijst;
}

public ArrayList zoekFilmOpSelectie(boolean[] _selectie, String _titel, String _jaar, String _genre, String _naam)
throws Melding
{
Logger gcoLogger = Logger.getLogger("gco.log");
ArrayList filmLijst = new ArrayList();
/* lokaal heb ik MySQL versie 4.1 die subqueries aankan
* op de server zit ik met versie 4.0 die nog geen subqueries aankan
* Dus moet ik een aantal SQL-statements herschrijven
*/
try {
Connection con = this.getDatabaseConnection();
StringBuffer zoekString = new StringBuffer();
if (_selectie[3] == false)
{
zoekString.append("select * from film where ");
} /* geen selectie op medewerker */

else {
zoekString.append("select * from film, filmrol, persoon "); zoekString.append(" where film.filmnummer = filmrol.filmnummer and ");
zoekString.append(" filmrol.persoonsnummer = persoon.persoonsnummer and ");
} /* wel selectie op medewerker */


if (_selectie[0] == true && _titel != null)
{
zoekString.append(" titel like '%" + _titel + "%'");
if (_selectie[1] == true || _selectie[2] == true
|| _selectie[3] == true)
{
zoekString.append(" and ");
}
} /* selectie op titel */

if (_selectie[1] == true && _jaar != null)
{
System.out.println("FilmDAO - zoeken op jaar" + _jaar);
zoekString.append(" jaarUitgave = " + _jaar + " ");
if (_selectie[2] == true || _selectie[3] == true)
{
zoekString.append(" and ");
}
} /* selectie op jaar */

if (_selectie[2] == true && _genre != null)
{
System.out.println("FilmDAO - zoeken op genre");
zoekString.append(" genre = '" + _genre + "' ");
if ( _selectie[3] == true)
{
zoekString.append(" and ");
}

} /* selectie op genre */
if (_selectie[3] == true && _naam != null)
{
System.out.println("FilmDAO - zoeken op naam");
zoekString.append(" (naam like '%" + _naam + "%' or ");
zoekString.append(" voornaam like '%" + _naam + "%' ) ");

} /* selectie op naam */


System.out.println("zoekstring is " + zoekString );
gcoLogger.debug("zoekstring is " + zoekString );
PreparedStatement ps = con.prepareStatement(zoekString.toString());
ResultSet rs = ps.executeQuery();
if (rs == null)
{
ps.close();
con.close();

} /* rs == null */
else {
while (rs.next())
{
Film film = new Film(rs, "lijst");
filmLijst.add(film);

} /* while rs.next() */
rs.close();
ps.close();
con.close();

} /* rs != null */

} catch (SQLException SQLEx)
{
Melding melding = new Melding(SQLEx);
throw melding;

} /* catch */
catch (Melding melding)
{
throw melding;
}

return filmLijst;
}

public Film zoekFilmOpNummer(String _nummer)
throws Melding
{
System.out.println(" FilmDao : zoeken van filmnummer " + _nummer);
Integer nummerInteger = new Integer(_nummer);
int nummer = nummerInteger.intValue();
StringBuffer zoekFilmString = new StringBuffer();
StringBuffer zoekPosterString = new StringBuffer();
StringBuffer zoekNulPosterString = new StringBuffer();
Film film ;
Connection con = null;
PreparedStatement ps = null;
ResultSet rsFilm = null;
ResultSet rsPoster = null;
/* syntax van de Left Join :
* select * from film left join filmposter on film.filmnummer = filmposter.filmnummer
*/
/* tweede poging van syntax :
* select * from film left join filmposter
* on film.filmnummer = filmposter.filmnummer
* where film.filmnummer = 5
* order by filmposter.volgnummer
*/
//zoekString.append("select * from film left join filmposter");
//zoekString.append(" on film.filmnummer = filmposter.filmnummer");
// zoekString.append(" and filmposter.volgnummer = 1 ");
// zoekString.append(" where film.filmnummer = ?");
zoekFilmString.append("select * from film");
zoekFilmString.append(" where filmnummer = ?");
zoekPosterString.append("select * from filmposter");
zoekPosterString.append(" where filmnummer = ?");
zoekNulPosterString.append("select * from filmposter");
zoekNulPosterString.append(" where filmnummer = 0");

try {
/* zoek filmdetail op basis van nummer */
con = getDatabaseConnection();
ps = con.prepareStatement(zoekFilmString.toString());
ps.setInt(1, nummer);
rsFilm = ps.executeQuery();
if (rsFilm.next())
{
film = new Film(rsFilm, "detail");
/* zoek filmposter */
ps = con.prepareStatement(zoekPosterString.toString());
ps.setInt(1, nummer);
rsPoster = ps.executeQuery();
if (rsPoster.next())
{
Blob poster = rsPoster.getBlob("poster");
film.setPoster(poster);
} /* if rs.next() == filmposter gevonden */
else {
ps = con.prepareStatement(zoekNulPosterString.toString());
rsPoster = ps.executeQuery();
if (rsPoster.next())
{
Blob poster = rsPoster.getBlob("poster");
film.setPoster(poster);
} /* zoek de NUL-poster */

} /* geen filmposter gevonden : zoek die
* van filmposter met nummer 0 */
/* zoek de technische fiche van de film */
film.setFilmPloeg(zoekMedewerkers(film, 1));
film.setRollenLijst(zoekMedewerkers(film, 2));

} /* if rs.next() == film gevonden */
else film = new Film();


} catch (SQLException sqlEx )
{
Melding melding = new Melding(sqlEx);
throw melding;
}

catch (Melding melding)
{
throw melding;
}




return film;
} /* zoekFilmOpNummer () */

private ArrayList zoekMedewerkers (Film _film, int _aard)
throws Melding, SQLException
{
Integer nummerInteger = new Integer(_film.getFilmnummer());
int nummer = nummerInteger.intValue();
Connection con = null;
PreparedStatement ps = null;
StringBuffer zoekString;
ResultSet rsMedewerker = null;
ArrayList mwLijst = new ArrayList();
try {
con = getDatabaseConnection();
zoekString = new StringBuffer();
zoekString.append("select * from filmrol, persoon ");
zoekString.append("where filmrol.persoonsnummer = persoon.persoonsnummer ");
if (_aard == 1)
{
zoekString.append("and filmrol.filmrol <> 'acteur' ");

}
else {
zoekString.append("and filmrol.filmrol = 'acteur' ");
} /* _aard != 1) */
zoekString.append("and filmnummer = ?");
ps = con.prepareStatement(zoekString.toString());
ps.setInt(1, nummer);
rsMedewerker = ps.executeQuery();
while (rsMedewerker.next())
{
FilmMedewerker filmMedewerker = new FilmMedewerker(rsMedewerker);
System.out.println("nieuwe medewerker " + filmMedewerker.getNaam());
mwLijst.add(filmMedewerker);

} /* while rsMedewerker */
if (_aard == 1)
{

}
else {

}

} catch (Melding melding)
{
throw melding;
}
catch (SQLException sqlEx)
{
Melding melding = new Melding(sqlEx);
throw melding;
}
finally {
if (rsMedewerker != null) rsMedewerker.close();
if (ps != null) ps.close();
if (con != null) con.close();
}


return mwLijst;
} /* zoekMedewerkersVanFilm() */


}

So now, we have the model or javabeans, the DAO who create the javabeans, the view or JSP's who display the
information inside the javabeans.
But which class takes control of the whole of the application ? That's the controller, and in a java web application we write the controller as a servlet. For a small web app, one single servlet should do.

With a servlet, you have 2 possibilities to call them : with a GET or a POST.
The difference between the 2 of them is simple : with GET, you always show the variables in the URL.
You've certainly seen URLS containg a question mark like this one :
http://www.amazon.com/exec/obidos/tg/detail/-/0596007736/qid=1114176032/sr=1-1/ref=sr_1_1/103-0402606-0055040?v=glance&s=books

The problem with this kind or URL's is that the user can change the value of the parameter and thus he might see a page which he isn't allowed to see.
Therefor, always write the following code in your servlet :
public void doGet (HttpServletRequest _request, HttpServletResponse _response)
throws ServletException, IOException
{
doPost (_request, _response);
} /* doGet() */

So, with this code, you are always referring to the POST method, no matter what.
A POST method takes care of the parameters without showing the parameters

The viewName to which I referred in my previous email, is merely a hidden variable inside the <FORM> tag of the JSP.
<Input type="hidden" name="viewNaam" value="/cluifAlfabet.jsp">

</form>


Whenever the user clicks on the submit button, each part of the FORM is put inside the request and given to the servlet. Therefor, the hidden field inside the <FORM> tag can be read by the servlet.

The next question is : now that we know who controls the web app (== the servlet), who starts the servlet ? That's Tomcat. And how does he do that ?
Well, If I type in http://localhost:8080 , I call Tomcat and he shows me the index page of Tomcat. If I want him to start my web app, I type in http://localhost:8080/gco/cluif.

With /gco I refer to the folder C:\Program Files\Apache Software Foundation\Tomcat 5.0\webapps\gco
Inside this folder , you have the web.xml inside the WEB-INF folder.
So, by typing http://localhost:8080/gco I ask Tomcat to look for the file WEB-INF\web.xml and read it
By adding cluif ( http://localhost:8080/gco/cluif) , I ask Tomcat to start the servlet which corresponds to the word cluif.
And with the following web.xml, Tomcat knows that by "cluif" I ask him to start the servlet called cluifcontroller.

<?xml version="1.0" encoding="ISO-8859-1"?>

<!DOCTYPE web-app

PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"

"http://java.sun.com/dtd/web-app_2_3.dtd">

<web-app>

<display-name>CLUIF</display-name>

<description>CLUb op het Internet voor Filmfanaten</description>

<servlet>

<servlet-name>LoggerServlet</servlet-name>

<servlet-class>org.gertcuppens.controller.LoggerServlet</servlet-class>

<init-param>

<param-name>properties</param-name>

<param-value>WEB-INF\classes\log4j.properties</param-value>

</init-param>

<load-on-startup>1</load-on-startup>

</servlet>

<servlet>

<servlet-name>org.gertcuppens.controller.CluifController</servlet-name>

<servlet-class>org.gertcuppens.controller.CluifController</servlet-class>

</servlet>

<servlet>

<servlet-name>org.gertcuppens.controller.ImageServlet</servlet-name>

<servlet-class>org.gertcuppens.controller.ImageServlet</servlet-class>

</servlet>

<servlet-mapping>

<servlet-name>org.gertcuppens.controller.CluifController</servlet-name>

<url-pattern>/cluif</url-pattern>

</servlet-mapping>

<servlet-mapping>

<servlet-name>org.gertcuppens.controller.ImageServlet</servlet-name>

<url-pattern>/cluifimg</url-pattern>

</servlet-mapping>

</web-app>

What happens in this private method ?

We take a look at what information the request contains, so we know what the user wants.
We look at the value of the radiobutton.

private String behandelAlfabet (HttpServletRequest _request)
{
Logger gcoLogger = Logger.getLogger("gco.log");
String radioLetter = _request.getParameter("radioLetter");
System.out.println("gcoController -- radioLetter is " + radioLetter);
gcoLogger.debug("gcoController -- radioLetter is " + radioLetter);

Then, we must know which button was pushed : was it the button "selecteren" (select) or zoeken (search) ?
If the user pushed the select button, the page he wants to see was
the selectionPage :

if (_request.getParameter("selecteren") != null)
{
System.out.println("button is selecteren");
gcoLogger.debug("button is selecteren");
return SELECTIE_PAGINA;
}

If it was the button zoeken or search, we must look for all the movies
beginning with the selected letter contained in the radiobutton.
And for this we need the FilmDao class.

else if (_request.getParameter("zoeken") != null)
{

System.out.println("button is zoeken");
gcoLogger.debug("button is zoeken");
HttpSession sessie = _request.getSession(true);
// if (sessie == null) sessie = _request.getSession(true);
FilmDao filmDao = new FilmDao();
ArrayList filmLijst = new ArrayList();

We give the radioLetter to the filmDao so it know which films
it has to look for

try {
filmLijst = filmDao.zoekFilmOpLetter(radioLetter);
Melding melding = new Melding("selectie op films beginnend met " + radioLetter);
_request.setAttribute("melding",melding);
} catch (Melding melding)
{
// Melding melding = new Melding(exc);
//HttpSession sessie = _request.getSession(false);
/* plaats de melding in request; als je melding
* in sessie plaatst, blijft de foutmelding terugkomen
* ook al is ze niet meer van toepassing
*/
_request.setAttribute("melding", melding);
System.out.println("gcoController -- melding klaargezet in behandelLetter() ");
System.out.println("melding boodschap is " + melding.getBoodschap());
System.out.println("melding SQL is" + melding.getSQLMelding());
}
sessie.setAttribute("filmLijst", filmLijst);
return FILMLIJST_PAGINA;
} /* selecteren geklikt */

This search will have given us the arrayList filmLijst as result.
We put this resultset in the request so the JSP can get it there
when it has to display the values of this arraylist on screen.

Always be prepared for the unexpected : if neither of the buttons
select or search has been pressed on, just go back to the alphabetPage.

else
{
System.out.println("behandelalfabet : onvoorzien geval");
gcoLogger.debug("behandelalfabet : onvoorzien geval ");
return ALFABET_PAGINA;
}
} /* behandelAlfabet () */

In short : you must always use the request to get your information from to know what to do. And put the found information in the request so that other objects may use this information to work on.