【IT168 技术资源】

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

public class test 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 run() ...{
String url = "jdbc:sybase:Tds:202.97.228.248:4100/pubs3";
String query = "select a from test";

try ...{
Class.forName("com.sybase.jdbc.SybDriver");

} catch(Exception ex) ...{
setError("Can't find Database driver class: " + ex);
return;
}

try ...{
Vector results = new Vector();
Connection con = DriverManager.getConnection(url,"sa", "great1");

Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery(query);
while (rs.next())
...{
String s = rs.getString("a");
//float f = rs.getFloat("PRICE"); 
String text = s;// + " " + f; 
results.addElement(text);
}

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

setResults(results);

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



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;
}
}

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

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