Skip site navigation (1) Skip section navigation (2)

still confuse; no suitable driver

From: radifan karami <radif_k(at)yahoo(dot)com>
To: pgsql-interfaces(at)postgresql(dot)org
Subject: still confuse; no suitable driver
Date: 2000-06-28 13:08:13
Message-ID: 20000628130813.11407.qmail@web5302.mail.yahoo.com (view raw or flat)
Thread:
Lists: pgsql-interfaces
I'm sory if may question is covered in mailing-list
archive.
I found many same questions ( and solutions ) in that
archive about driver problem when running jdbc-applet
from browser.

I use Linux, Postgresql 7 and Java 1.2.2.

I'm new commer in Java, and try to make the first
jdbc-applet code following the tutorial in
java.sun.com.

It's working perfectly by appletviewer.

I put my applet code ( .class ) and postgresql.jar
file in the web server ( in my home page ), separate
from my database in may host.
For example my homepage is http://www.xxx.ac.jp/~radif
and my host name is graphium.xxx.ac.jp.

There is an error "Javalang.ClassNotFoudException: No
suitable driver ", when I run applet from browser.

I read many solutions in archive, but still not
understand. Please give a simple and clear solution.

** The html code is :
<HTML>
<HEAD>
<TITLE> Query Output </TITLE>
</HEAD>
<BODY>
Output from query 
select NAME, PRICE from COFFEES 
<APPLET CODE="myapplet" ARCHIVE="postgresql.jar"
width=600 height=300>
</APPLET>
</BODY>
</HTML>


** The applet code is :
import java.applet.Applet;
import java.awt.Graphics;
import java.util.Vector;
import java.sql.*;

public class myapplet extends Applet implements
Runnable {
    private Thread worker;
    private Vector queryResults;
    private String message = "Initializing";

    public synchronized void start() {
	// Every time "start" is called we create a worker
thread to
	// re-evaluate the database query.
	if (worker == null) {	
	    message = "Connecting to database";
            worker = new Thread(this);
	    worker.start();
	}
    }

    /**
     * The "run" method is called from the worker
thread.  Notice that
     * because this method is doing potentially slow
databases accesses
     * we avoid making it a synchronized method.
     */

    public void run() {
	String url =
"jdbc:postgresql://graphium.xxx.ac.jp/coffeebreak";
	String query = "select COF_NAME, PRICE from COFFEES";
	
	try {
	    Class.forName("org.postgresql.Driver");
	} catch(java.lang.ClassNotFoundException ex) {
	    setError("Masalah pada driver: " + ex);
	    return;
	}

	try {
	    Vector results = new Vector();
	    Connection con =
DriverManager.getConnection(url,"my", "");
	    Statement stmt = con.createStatement();
	    ResultSet rs = stmt.executeQuery(query);
	    while (rs.next()) {
		String s = rs.getString("COF_NAME");
		float f = rs.getFloat("PRICE");
		String text = s + "     " + f;
		results.addElement(text);
	    }

	    stmt.close();
	    con.close();

	    setResults(results);

	} catch(SQLException ex) {
	    setError("SQLException: " + ex);
	}
    }

    /**
     * The "paint" method is called by AWT when it
wants us to
     * display our current state on the screen.
     */

    public synchronized void paint(Graphics g) {
	// If there are no results available, display the
current message.
	if (queryResults == null) {
	    g.drawString(message, 5, 50);
	    return;
	}

	// Display the results.
	g.drawString("Prices of coffee per pound:  ", 5, 10);
	int y = 30;
	java.util.Enumeration enum = queryResults.elements();
	while (enum.hasMoreElements()) {
	    String text = (String)enum.nextElement();
	    g.drawString(text, 5, y);
	    y = y + 15;
	}
    }

    /**
     * This private method is used to record an error
message for
     * later display.
     */

    private synchronized void setError(String mess) {
	queryResults = null;	
	message = mess;	
	worker = null;
	// And ask AWT to repaint this applet.
	repaint();
    }

    /**
     * This private method is used to record the
results of a query, for
     * later display.
     */

    private synchronized void setResults(Vector
results) {
	queryResults = results;
	worker = null;
	// And ask AWT to repaint this applet.
	repaint();
    }
}

 
Thank you & regard,

-Radifan-
  

__________________________________________________
Do You Yahoo!?
Get Yahoo! Mail - Free email you can access from anywhere!
http://mail.yahoo.com/

Responses

pgsql-interfaces by date

Next:From: Kardos, Dr. AndreasDate: 2000-06-28 13:38:00
Subject: Re: ODBC question
Previous:From: Carolyn Lu WongDate: 2000-06-28 12:40:44
Subject: ODBC question

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group