JDBC connection to an Oracle Database  

A student emailed me asking me how to connect to Oracle Database from within a Java Program.

The following is a simple complete example


package model;

import java.sql.*;

import oracle.jdbc.OracleDriver;


public class Class1 {

    public Class1() {



        String username = "scott";   // standard usename and password for SCOTT tiger USER

        String password = "tiger";

        String thinConn = "jdbc:oracle:thin:@localhost:1521:ORCL"; 


         //The above line defines the connection string of the target database.

        //  It is important to specify the correct one,, it has the format

        //  jdbc:oracle:thin@server_address:listener_port:Oracle_instance_SID

        //  The first part before @ sign is fixed,, however you  may need to change the other part according to you env.

        //  Server_address  is the IP address or server name of the host computer that is running Oracel

        //                           if you are running Oracle on your machine you can use either localhost or

        //  Listner_Port      : If the TCP/IP port number that the Oracle listener is using  typically    1521

        //  Instance_ID      :  Each Oracle installation creates an Instance and and identifier is given to this instance

        //                            If you installed Oracle and used default setting, it is most probably ORCL

         //                           you can find out this value by logging as SYS or SYSTEM user and run the following query

         //                            SELECT * FROM V$INSTANCE and look for the instance name columm


        DriverManager.registerDriver(new OracleDriver());

        Connection conn = DriverManager.getConnection(thinConn,username,password);


        Statement stmt =       conn.createStatement ();

        ResultSet rset =      stmt.executeQuery ( "select * from EMPLOYEES"); // The SQL statement

        while (rset.next ())

         System.out.println(  rset.getString (2));   //print the second field



    //    return conn;


    catch (

    SQLException x)

    {System.out.println("SQL Error");}



    public static void main(String[] args) {

        Class1 class1 = new Class1();