D:\work\db\src\Example1.java
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1
2 import java.sql.Connection;
3 import java.sql.DriverManager;
4 import java.sql.SQLException;
5
6 /**
7 * This is a simple example that demostrates how to open a database
8 * connection before we are trying to execute SQL statements, and
9 * close a database connection when we are done. You can build your
10 * code using this example as a skeleton.
11 */
12 public class Example1 {
13 public static void main(String args[]) {
14 Example1 example = new Example1();
15 example.run();
16 }
17
18 /**
19 * This is the skeleton code of database access
20 */
21 public void run() {
22 Connection con = null;
23 try {
24 con = openConnection();
25 } catch (SQLException e) {
26 System.err.println("Errors occurs when communicating with the database server: " + e.getMessage());
27 } catch (ClassNotFoundException e) {
28 System.err.println("Cannot find the database driver");
29 } finally {
30 // Never forget to close database connection
31 closeConnection(con);
32 }
33 }
34
35 /**
36 *
37 * @return a database connection
38 * @throws SQLException when there is an error when trying to connect database
39 * @throws ClassNotFoundException when the database driver is not found.
40 */
41 private Connection openConnection() throws SQLException, ClassNotFoundException {
42 // Load the Oracle database driver
43 DriverManager.registerDriver(new oracle.jdbc.OracleDriver());
44
45 /*
46 Here is the information needed when connecting to a database
47 server. These values are now hard-coded in the program. In
48 general, they should be stored in some configuration file and
49 read at run time.
50 */
51 String host = "shams.usc.edu";
52 String port = "1521";
53 String dbName = "cs585";
54 String userName = "temp";
55 String password = "temp585";
56
57 // Construct the JDBC URL
58 String dbURL = "jdbc:oracle:thin:@" + host + ":" + port + ":" + dbName;
59 return DriverManager.getConnection(dbURL, userName, password);
60 }
61
62 /**
63 * Close the database connection
64 * @param con
65 */
66 private void closeConnection(Connection con) {
67 try {
68 con.close();
69 } catch (SQLException e) {
70 System.err.println("Cannot close connection: " + e.getMessage());
71 }
72 }
73 }