/*
 * @(#)Graph.java       1.7 98/07/17
 *
 * Copyright 1997, 1998, 1999 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */

/**
 * This is a demonstration JDBC applet.
 * It displays some simple standard output from the Coffee database.
 */

import java.applet.Applet;
import java.awt.Graphics;
import java.util.Vector;
import java.sql.*;

public class OutputApplet 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();
	
	}
    }

    public void init() {

    }

    /**
     * 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() {
	// Getting the parameter for jdbcUrl from the calling html file
	// This enables retargeting of the applet 
	String url = getParameter("jdbcUrl");
	// if the JOB jdbc url contains 'appletHost' as the host designation
	// We can map this to the actual host on which the applet is running
	
	// Normally you do not need to use "appletHost" in the
	// JDBC url. Instead, you should replace it with the full hostname,
	// or IP  address of the machine on which you installed the
	// Easysoft JDBC-ODBC Bridge (JOB) server.

        // Use "appletHost" in the JDBC url if you  do not
	// know in advance the name of the machine where JOB server
	// and your applet will be installed.

	// 'appletHost' designation allows you to write code to connect to a
	// JOB server on a host which is specified at run time.

        // If the 'appletHost' host designation is used in the
        // Easysoft JDBC url the Easysoft JDBC-ODBC Bridge driver expects 
	// to find the key value pair
        //
	//     "appletHost", <JOB Server host machine> in the
	// 
        // java.util.Properties passed to the DriverManager.getConnection 
	// method.
        // To set up this mapping do the following:
	// get the hostname for the machine where the applet is served from
	// The JOB Server needs to be running on this box too 
	// as applet restrictions allow TPC/IP connections only to the
	// machine from which the applet has been served.
	
		
	    String hostString = getCodeBase().getHost();
	    // Create Properties object
	    java.util.Properties info = new java.util.Properties();
	    // Add to the properties list the key "appletHost"
	    // with value the host of the JOB server
	    info.put("appletHost",hostString);
	    // Add "user" <db user> key/value pair
	    // info.put("user","db user name");
	    // Add "password" <db password> key/value pair
	    //info.put("password","db user password");
	    // Load the driver
	    try {
	    Class.forName("easysoft.sql.jobDriver").newInstance();
	} catch(Exception ex) {
	    setError("Can't find Database driver class: " + ex);
	    return;
	}
	    try {
	    // Now establish connection with via the Driver manager
	    Connection con = DriverManager.getConnection(url,
							 info);
	    Vector results = new Vector();
	    String query = "select COF_NAME, PRICE from COFFEES";
	    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();
    }
}