I managed to get the jdbc-thin sample applet working shortly
after posting the message.
I made the following two changes to the java source
//output.setText (null);
output.setText ("");
// Class.forName (driver_class);
Class t = Class.forName (driver_class);
Write Once Run Anywhere???
###########################################################
Original Post Follows:
To: alpha-osf-managers_at_ornl.gov
Subject: Having Java Difficulties ...
Date: Wed, 01 Jul 1998 08:35:55 -0400
I must be missing something!
I have downloaded the jdbcthin.tar file for Unix, from Oracles Web Page
(
http://www.oracle.com/nca/java_nca/jdbc/v7/html/download.html). This
tar file contains the classes111.zip (jdbc thin driver) file and some
samples. The JdbcApplet.java and JdbcApplet.htm in the directory
samples/thin reside in the htdocs directory on my Alpha 3700 running
DU 4.0D and JDK 1.1.6. This jdbc-thin test applet works fine when it
is accessed via a browser from a Win-95 system, but not from a browser
or even the appletviewer on the Alpha console.
>From the Win-95 machine, the applet is executed. When I press the
"Hello JDBC" button I get connected to the Oracle database and
get the results I expect.
>From the Alpha Console (Netscape Communicator 4.05 Browser or Appletviewer),
the applet is executed. When I press the "Hello JDBC" button I get the word
"null". No errors are generated in the Java Console Window.
I get the same results using JDK 1.1.4, 1.1.5, and 1.1.6
I have checked all available documentation and have found no resolution.
Can someone please clue me in?
Thank you,
Jack Burton
################################################################################
The Java Source file (JdbcApplet.java) follows:
/*
* This sample applet just selects 'Hello World' and the date from the database
*/
// Import the JDBC classes
import java.sql.*;
// Import the java classes used in applets
import java.awt.*;
import java.io.*;
import java.util.*;
public class JdbcApplet extends java.applet.Applet
{
// The driver to load
static final String driver_class = "oracle.jdbc.driver.OracleDriver";
// The connect string
static final String connect_string =
"jdbc:oracle:thin:mylogin/mypass_at_pgw6:1521:repair";
// The query we will execute
static final String query = "select 'Hello JDBC: ' || sysdate from dual";
// The button to push for executing the query
Button execute_button;
// The place where to dump the query result
TextArea output;
// The connection to the database
Connection conn;
// Create the User Interface
public void init ()
{
this.setLayout (new BorderLayout ());
Panel p = new Panel ();
p.setLayout (new FlowLayout (FlowLayout.LEFT));
execute_button = new Button ("Hello JDBC");
p.add (execute_button);
this.add ("North", p);
output = new TextArea (10, 60);
this.add ("Center", output);
}
// Do the work
public boolean action (Event ev, Object arg)
{
if (ev.target == execute_button)
{
try
{
// Clear the output area
output.setText (null);
// See if we need to open the connection to the database
if (conn == null)
{
// Load the JDBC driver
output.appendText ("Loading JDBC driver " + driver_class + "\n");
Class.forName (driver_class);
// Connect to the databse
output.appendText ("Connecting to " + connect_string + "\n");
conn = DriverManager.getConnection (connect_string);
output.appendText ("Connected\n");
}
// Create a statement
Statement stmt = conn.createStatement ();
// Execute the query
output.appendText ("Executing query " + query + "\n");
ResultSet rset = stmt.executeQuery (query);
// Dump the result
while (rset.next ())
output.appendText (rset.getString (1) + "\n");
// We're done
output.appendText ("done.\n");
}
catch (Exception e)
{
// Oops
output.appendText (e.getMessage () + "\n");
}
return true;
}
else
return false;
}
}
#############################################################################
The Html file (JdbcApplet.htm) follows:
<html>
<head>
<title>JDBC applet</title>
</head>
<body>
<h1>JDBC applet</h1>
This page contains an example of an applet that uses the Thin JDBC
driver to connect to Oracle.<p>
The source code for the applet is in <a
href="JdbcApplet.java">JdbcApplet.java</a>. Please check carefully
the driver class name and the connect string in the code.<p>
The Applet tag in this file contains a CODEBASE entry that must be set
to point to a directory containing the Java classes from the Thin JDBC
distribution *and* the compiled JdbcApplet.class.<p>
As distributed it will *not* work because the classes111.zip are not
in this directory.<p>
<hr>
<applet codebase="." archive="classes111.zip"
code="JdbcApplet" width=500 height=200>
</applet>
<hr>
Received on Thu Jul 02 1998 - 13:36:07 NZST