1 /**
2 *
3 */
4 package demo;
5
6 import java.io.IOException;
7 import java.io.PrintWriter;
8 import java.sql.Connection;
9 import java.sql.DriverManager;
10 import java.sql.PreparedStatement;
11 import java.sql.ResultSet;
12 import java.sql.SQLException;
13
14 import javax.servlet.ServletException;
15 import javax.servlet.http.HttpServlet;
16 import javax.servlet.http.HttpServletRequest;
17 import javax.servlet.http.HttpServletResponse;
18
19 /**
20 * Reading DB Config from web.xml
21 */
22 public class DBServlet extends HttpServlet {
23
24 /**
25 *
26 */
27 private static final long serialVersionUID = 1L;
28
29 private String diverClass;
30 private String userName;
31 private String password;
32 private String url;
33
34 @Override
35 public void init() throws ServletException {
36 diverClass = /* getServletConfig(). */getServletContext().getInitParameter("driver");
37 userName = /* getServletConfig(). */getServletContext().getInitParameter("username");
38 password = /* getServletConfig(). */getServletContext().getInitParameter("password");
39 url = /* getServletConfig(). */getServletContext().getInitParameter("url");
40
41 try {
42 Class.forName(diverClass);
43 } catch (Exception e) {
44 e.printStackTrace();
45 }
46
47 }
48
49 @Override
50 protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
51 Connection connection = null;
52 PreparedStatement statement = null;
53
54 try {
55 connection = DriverManager.getConnection(url, userName, password);
56 statement = connection.prepareStatement("select * from customer");
57 ResultSet rs = statement.executeQuery();
58
59 PrintWriter printWriter = resp.getWriter();
60 while (rs.next()) {
61 printWriter.println(rs.getString("id"));
62 printWriter.println(rs.getString("name"));
63 }
64 } catch (SQLException e) {
65 e.printStackTrace();
66 } finally {
67 try {
68 if (statement != null) {
69 statement.close();
70 }
71
72 if (connection != null) {
73 connection.close();
74 }
75 } catch (SQLException e) {
76 e.printStackTrace();
77 }
78 }
79 }
80 }
