// File: Students.java // Last Updated: 9-Jan-2013 package mypackage; //Import Servlet Libraries import javax.servlet.*; import javax.servlet.http.*; import javax.servlet.annotation.*; //Import Java Libraries import java.io.*; import java.sql.*; @WebServlet("/students") public class Students extends HttpServlet { String driver = "com.mysql.jdbc.Driver"; // Θα χρειαστεί να προσαρμόσετε την βάση δεδομένων στην teddb String dbURL = "jdbc:mysql://localhost/teddb?user=ted&password=ted!"; public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException { String qry = "select id, first_name, last_name, semester, email from students"; String[] columns = new String[] { "id", "first_name", "last_name", "semester", "email" }; String[] columnsVisible = new String [] { "ΑΜ","ΟΝΟΜΑ","ΕΠΩΝΥΜΟ","ΕΞΑΜΗΝΟ","EMAIL" }; Connection dbCon; res.setContentType("text/html"); res.setCharacterEncoding("utf-8"); PrintWriter out = res.getWriter(); try { Class.forName(driver); dbCon = DriverManager.getConnection(dbURL); ResultSet rs; Statement stmt; stmt = dbCon.createStatement(); rs = stmt.executeQuery(qry); out.println(""); printForm(out); printAnyError(out, req); //Printing the table out.println("

"); out.println(""); for (int i = 0; i < columns.length; i++) { out.print(""); } while (rs.next()) { out.println(""); for (int i = 0; i < columns.length; i++) { out.println(""); } out.println("\n"); } out.println("

"); out.print(columnsVisible[i].toUpperCase()); out.print("

"); out.println(rs.getString(columns[i])); out.println("

"); rs.close(); stmt.close(); dbCon.close(); } catch (Exception e) { out.println(e.toString()); } finally { out.close(); } } public void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException { String qry = "insert into students (id, first_name, last_name, semester, email) values (? ,? ,? ,?, ?)"; Connection dbCon; req.setCharacterEncoding("utf-8"); String am = req.getParameter("am"); String onoma = req.getParameter("onoma"); String eponimo = req.getParameter("eponimo"); String examino = req.getParameter("examino"); String email = req.getParameter("email"); try { Class.forName(driver); dbCon = DriverManager.getConnection(dbURL); PreparedStatement stmt; stmt = dbCon.prepareStatement(qry); stmt.setString(1, am); stmt.setString(2, onoma); stmt.setString(3, eponimo); stmt.setString(4, examino); stmt.setString(5, email); int i = stmt.executeUpdate(); System.out.println("Inserted " + i + " row(s)"); res.sendRedirect("students"); } catch (Exception e) { res.sendRedirect("students?errormsg=" + e.getMessage()); } } void printForm(PrintWriter out) { out.println(""); } void printAnyError(PrintWriter out, HttpServletRequest req) { String errorMessage = req.getParameter("errormsg"); if (errorMessage != null) { out.println("
Error: "+ errorMessage + ""); } } }