Access oracle database from different classes in desktop / standalone app.

Question

I am a bit confused as to what way to go. I am building a desktop application that needs to access an oracle database. I have done this in the past using code similar to the following:
        try {             DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());             Connection conn = DriverManager.getConnection(                     "jdbc:oracle:thin:@111.111.111.111:oracledb",                     "username", "password" );             // Create a Statement             Statement stmt = conn.createStatement();             ResultSet rs = stmt.executeQuery(                     "select ... from ...");             while (rs.next()) {                 ReportNumberCombo.addItem(rs.getString(1));             } // end of rs while             conn.close();         } //  end of try         catch( Exception e ) {             e.printStackTrace();         }
The problem I would like to resolve is that I have this code all over the place in my application. I would like to have it in one objects method that i can call from other classes. I can't easily see how to do this, or maybe at this point I'm just too confused.
I want to be able to change this connection info from a properties file which I have already done, not sure if this bit of information would change the answer to my question. I was also looking at the DataSource api, this looks like it is close to what I should use, what are your thoughts?
I would also like to if JNDI is only for web applications or would be appropriate for a desktop app.
Thank you for your help, I realize this is all over the place but I really need these topics cleared up!

Answer 1

I have tried exactly that and am getting an error which let me to believe it couldn't be done that way. Here is my code and error message:
public class readPropsFile {
    String getURL() throws IOException {
        // default values for properties file
        String Family = "Family:jdbc" + ":oracle:" + "thin:@";
        String Server = "Server:111.111.111.111";
        String Port = "Port:1521";
        String Host = "Host:oradb";
        String Username = "Username:username";
        String Password = "Password:password";
        try {          
            new BufferedReader(new FileReader("C:\\data\\Properties.txt"));
        } catch (FileNotFoundException filenotfound) {
            System.out.println("Error: " + filenotfound.getMessage());
            // displays to console if file DOES NOT exist
            System.out.println("The file DOES NOT exist, now creating...");
            FileWriter fileObject = null;
            fileObject = new FileWriter("c:\\data\\Properties.txt");
            BufferedWriter out = new BufferedWriter(fileObject);
            // writes to output as simple text.
            out.write(Family);
            out.newLine();
            out.write(Server);
            out.newLine();
            out.write(Port);
            out.newLine();
            out.write(Host);
            out.newLine();
            out.write(Username);
            out.newLine();
            out.write(Password);
            out.newLine();
            out.close();
        // displays to console if file exists
        System.out.println("The file exists, or was created sucessfully");
//      creates the properties object, assigns text file.
        Properties props = new Properties();
        FileInputStream in = new FileInputStream("c:\\data\\Properties.txt");
        props.load(in);
        Family = props.getProperty("Family");
        Server = props.getProperty("Server");
        Port = props.getProperty("Port");
        Host = props.getProperty("Host");
        Username = props.getProperty("Username");
        Password = props.getProperty("Password");
//      prints properties to a file for troubleshooting
        PrintStream s = new PrintStream("c:\\data\\list.txt");
        props.list(s);
        in.close();
        String URL = "\"" + Family + Server + ":" + Port + ":" + Host + "\"" +
                "," + "\"" + Username + "\"" + "," + "\"" + Password + "\"";
        System.out.println("This is the URL:" + URL);
        return URL;
}And here is where I try to call the method:
public class connWithProps1 {
    public static void main(String[] args) {
        readPropsFile callProps = new readPropsFile();
        try {
            callProps.getURL();
            String url = callProps.getURL(); // not needed
            System.out.println("The URL (in connWithProps1) is: " + csoProps.getURL());
            DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
            Connection conn = DriverManager.getConnection(url);
            // Create a Statement
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery("select .... WHERE ....'");
            while (rs.next()) {
                System.out.println(rs.getString(1));
            } // end of rs while
            conn.close();
        } catch (SQLException sqle) {
            Logger.getLogger(connWithProps1.class.getName()).log(Level.SEVERE, null, sqle);
        } catch (IOException ioe) {
            Logger.getLogger(connWithProps1.class.getName()).log(Level.SEVERE, null, ioe);
}The error I get is:
SEVERE: null
java.sql.SQLException: Listener refused the connection with the following error:
ORA-12505, TNS:listener does not currently know of SID given in connect descriptor
The Connection descriptor used by the client was:
111.111.111.111:1521:oradb","username","password"
        at oracle.jdbc.driver.SQLStateMapping.newSQLException(SQLStateMapping.java:70)
        at oracle.jdbc.driver.DatabaseError.newSQLException(DatabaseError.java:112)
        at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:173)
        at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:460)
        at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:411)
        at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:490)
        at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:202)
        at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:33)
        at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:474)
{code}
Although the URL prints out correctly and when I tried plugging in the URL manually, it works just fine. One other thing I noticed was the line "The file exists, or was created sucessfully" is output 3 times.
I will go back and change my code to properly close the resultset, thanks for catching that. Id rather use what I have instead of JNDI unless it's nesessary.
Edited by: shadow_coder on Jun 19, 2009 2:16 PM