akshaya ramkumar
i hv just started with my lessons in jsp n also doin my final yr project in jsp.i m doin the login page & m stuck with a problem in validating the user.the code i hv written below doesnt redirect to the login page if username & password is invalid but it does redirect only if the username is valid and password invalid.i want know wer i am going wrong in this: import java.io.*; import java.util.*; import java.sql.*; import javax.servlet.*; import javax.servlet.http.*;
public class Login2 extends HttpServlet{
private ServletConfig config;
public void init(ServletConfig config)
throws ServletException{
this.config=config;
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException,IOException{
String userlog = request.getParameter("textfield");
String passlog = request.getParameter("textfield2");
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String connectionURL = "jdbc:postgresql:rohan";
Connection connection=null;
PreparedStatement ps=null;
ResultSet rs=null;
try {
Class.forName("org.postgresql.Driver");
}catch(ClassNotFoundException cnfe){ cnfe.printStackTrace(); }
try{ connection = DriverManager.getConnection(connectionURL, "postgres", "postgres");
String sql = "select * from pass where username = ?";
ps = connection.prepareStatement(sql);
ps.setString(1,userlog);
rs = ps.executeQuery();
String dbuser=null;
String dbpass=null;
while (rs.next()){
dbuser = rs.getString(1);
out.println(dbuser);
dbpass = rs.getString(2);
out.println(dbpass);
}
if(dbuser.equals(userlog) && dbpass.equals(passlog))
{
response.sendRedirect("http://localhost:8080/LoginAuthentication/servlets/xx.jsp");
}else response.sendRedirect("http://localhost:8080/LoginAuthentication/servlets/log2.jsp");
}catch(Exception e){
out.println(e);
out.println("Invalid");
}
finally{
try{
if(rs!=null) rs.close(); if(ps!=null) ps.close(); if(connection!=null) connection.close();
}catch(SQLException se){
se.printStackTrace();
}
}
/* if(userName.equals(request.getParameter("user"))
&& passwrd.equals(request.getParameter("pass"))){
out.println("WELCOME "+userName);
}
else{
out.println("Please enter correct username and password");
out.println("
Login again");
session.setAttribute("UserName", request.getParameter("UserName"));
out.println("Welcome " + session.getAttribute( "UserName" ));
if (session.getAttribute("UserName").equals(""))
{
out.println("<a href="login.jsp"><b>Login </b></a>");
}
else{
out.println("<a href="logout.jsp"><b>Logout</b></a>");
}*/
}
}
January 5, 2011 at 10:53 AM
Hi Friend,
Try the following code:
1)login.jsp:
<html>
<script>
function validate(){
var username=document.form.user.value;
var password=document.form.pass.value;
if(username==""){
alert("Enter Username!");
return false;
}
if(password==""){
alert("Enter Password!");
return false;
}
return true;
}
</script>
<form name="form" method="post" action="../Login1" onsubmit="javascript:return validate();">
<table>
<tr><td>Username:</td><td><input type="text" name="user"></td></tr>
<tr><td>Password:</td><td><input type="password" name="pass"></td></tr>
<tr><td></td><td><input type="submit" value="Submit"></td></tr>
</table>
</form>
</html>
2)Login1.java:
import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class Login1 extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet { static final long serialVersionUID = 1L;
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
try{
response.setContentType("text/html");
PrintWriter out=response.getWriter();
String user=request.getParameter("user");
String pass=request.getParameter("pass") ;
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "root");
Statement st=con.createStatement();
ResultSet rs=st.executeQuery("select * from login where username='"+user+"' and password='"+pass+"'");
int count=0;
while(rs.next())
{
count++;
}
if(count>0)
{
out.println("welcome "+user);
}
else
{
response.sendRedirect("./jsp/login.jsp");
}
}catch (Exception e) {
e.printStackTrace();
}
}
}
Thanks
January 5, 2011 at 10:53 AM
Hi Friend,
Try the following code:
1)login.jsp:
<html>
<script>
function validate(){
var username=document.form.user.value;
var password=document.form.pass.value;
if(username==""){
alert("Enter Username!");
return false;
}
if(password==""){
alert("Enter Password!");
return false;
}
return true;
}
</script>
<form name="form" method="post" action="../Login1" onsubmit="javascript:return validate();">
<table>
<tr><td>Username:</td><td><input type="text" name="user"></td></tr>
<tr><td>Password:</td><td><input type="password" name="pass"></td></tr>
<tr><td></td><td><input type="submit" value="Submit"></td></tr>
</table>
</form>
</html>
2)Login1.java:
import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class Login1 extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet { static final long serialVersionUID = 1L;
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
try{
response.setContentType("text/html");
PrintWriter out=response.getWriter();
String user=request.getParameter("user");
String pass=request.getParameter("pass") ;
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "root");
Statement st=con.createStatement();
ResultSet rs=st.executeQuery("select * from login where username='"+user+"' and password='"+pass+"'");
int count=0;
while(rs.next())
{
count++;
}
if(count>0)
{
out.println("welcome "+user);
}
else
{
response.sendRedirect("./jsp/login.jsp");
}
}catch (Exception e) {
e.printStackTrace();
}
}
}
Thanks
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