JDBC Applet problem

[Arthur Johnson]

I am trying to run a sample JDBC Applet code I picked from Sun's Java web site. I have a Derby DB sitting on my local PC and thought I would be able to leverage the sample to connect to this local DB and issue a select SQL statement and display the results. But it throws me an error stating:

SQLException: java.sql.SQLException: Not suitable driver found
Any pointers as to why I am getting this error?

My CLASSPATH environment variable is set to:
C:\db-derby-10.3.2.1-bin\lib\derby.jar;.;C:\Program Files\Java\jre1.6.0_03\lib\ext\QTJava.zip

Sample Java Code:

/** 
 * This is a demonstration JDBC applet. 
 * It displays some simple standard output from the AssetDB Derby database. 
 */ 
 
import java.applet.Applet; 
import java.awt.Graphics; 
import java.util.Vector; 
import java.sql.*; 
 
public class DerbyDBAppletApp 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 driver = "org.apache.derby.jdbc.EmbeddedDriver"; 
                String dbName="/DerbyDB/AssetDB"; 
                String connectionURL = "jdbc:derby:" + dbName; 
                Connection conn = null; 
                
                try{ 
                    Class.forName(driver); 
                } catch(java.lang.ClassNotFoundException e) { 
                    e.printStackTrace(); 
                } 
                
                try { 
                        Vector results = new Vector(); 
                    String strResults = new String(); 
                    conn = DriverManager.getConnection(connectionURL); 
                
                    //body of code to go here 
                    Statement st=conn.createStatement(); 
                
                    ResultSet rs=st.executeQuery("SELECT * FROM USERS"); 
                    while (rs.next()){ 
                     String first=rs.getString("FIRST_NAME"); 
                     String last=rs.getString("LAST_NAME"); 
                    strResults = "Name: " + first + " " + last; 
                    results.addElement(strResults); 
 
                    } 
                     rs.close(); 
                         conn.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 enumer1 = queryResults.elements(); 
        while (enumer1.hasMoreElements()) { 
            String text = (String)enumer1.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(); 
    } 
}

Thanks in advance for any help.

Arthur
[ December 19, 2007: Message edited by: Arthur Johnson ]

[Jeanne Boyarsky]

Arthur,
Welcome to JavaRanch!

I'm going to move this to our Applets forum where they know about how classpaths affect applets.

[Ulf Dittmer]

Applets do not use the CLASSPATH variable. You need to include all necessary jar files in the archive attribute of the applet tag. See here for more detail on that.

Also be aware that if Derby needs access to the local file system (and I think it does, although it may have in-memory modes), which applets do not have for security reasons - it would need to be signed. See HowCanAnAppletReadFilesOnTheLocalFileSystem for further information.
[ December 21, 2007: Message edited by: Ulf Dittmer ]