User login
Please enter your Username and Password
Username:
Password:
Servlet: validator.java
public class Validator extends HttpServlet {
public void init(ServletConfig cfg) throws ServletException{
super.init(cfg);
}
/** Processes requests for both HTTP GET and POST methods.
* @param request servlet request
* @param response servlet response
*/
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException{
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
Enumeration paramNames = request.getParameterNames();
HttpSession session = request.getSession();
out.println("");
out.println("");
out.println("Message");
out.println("");
out.println("");
try{
validate(request, session);
if(session.getAttribute("validated").toString().equalsIgnoreCase("true")){
out.println("Successful");
}
else{
session.setAttribute("Username",request.getParameterValues("Username")[0]);
session.setAttribute("Password","");
response.sendRedirect("/OnlineForum/userlogin.jsp");
}
}catch(SQLException ex){
out.println(""+"Servlet could not access database - "+ex.getMessage()+"");
}catch(ClassNotFoundException ex){
out.println(""+"JDBC Driver not found - "+ex.getMessage()+"");
}
out.println("");
out.println("");
out.close();
}
//
/** Handles the HTTP GET method.
* @param request servlet request
* @param response servlet response
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException{
processRequest(request, response);
}
/** Handles the HTTP POST method.
* @param request servlet request
* @param response servlet response
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException{
processRequest(request, response);
}
public void validate(HttpServletRequest request, HttpSession session)throws SQLException, ClassNotFoundException{
boolean validated = false;
ResultSet rs = accessDataTable("SELECT * FROM Users");
try{
if(rs != null){
while(rs.next()){
if(rs.getString("Username").toString().equals(request.getParameterValues("Username")[0]) &&
rs.getString("Password").toString().equals(request.getParameterValues("Password")[0])){
validated = true;
session.setAttribute("Username", request.getParameterValues("Username")[0]);
session.setAttribute("Password", request.getParameterValues("Password")[0]);
}
}
}
}catch(SQLException ex){
throw new SQLException(ex.getMessage());
}
if(validated)session.setAttribute("validated","true");
else session.setAttribute("validated","false");
}
public ResultSet accessDataTable(String sql)throws SQLException, ClassNotFoundException{
/*Connect to DBMS*/
Connection conn = null;
Statement statement = null;
ResultSet rs = null;
try{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
conn = DriverManager.getConnection("jdbc:odbc:DBMS");
statement = conn.createStatement();
rs = statement.executeQuery(sql);
}catch(SQLException ex){
throw new SQLException(ex.getMessage());
}
return rs;
}
/** Returns a short description of the servlet.
*/
public String getServletInfo() {
return "Short description";
}
public void destroy(){
super.destroy();
}
<%=error%>
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