How can we access database with servlets?

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DATABASE ACCESS WITH SERVLETS

Database access with servlets is the same as JDBC. Only the difference is that we have a mysql-connector.jar file in the WEB-INF directory inside our root directory.

Example

//login.html file

<html>

<head>

<Title> login page </Title>

</head>

<body>

<br><br>

<font color=blue size=12> <center> User Authentication page

</center></font>

<hr color=red size=3>

<br><br> <br>

<form action="Login" method="post">

<center>

<table>

<tr> <td> User ID </td> <td> <input type=text name=txtid></td></tr>

<tr> <td> Password </td> <td> <input type=password

name=txtpass></td></tr>

<tr> <td colspan=2 align=center>

<input type=submit value=OK>

<input type=reset></td></tr>

</table>

</form>

</body>

</html>

//Login.java File

import java.io.*;

import java.sql.;

import javax.servlet.*;

import javax.servlet.http.*;

public class Login extends HttpServlet

{

Connection con=null;

public void doPost(HttpServletRequest reg, HttpServletResponse resp)

throws IOException, ServletException

{

Printwriter out=resp.getWriter();

resp.setContentType("text/html");

String url="jdbc:mysql://localhost/Test";

try {

String n=req.getParameter("txtid");

String p=req.getParameter("txtpass");

Class.ForName("com.mysql.jdbc.Driver");

con=DriverManager.getConnection(url, "root", "arjun");

Statement stmt=con.createStatement(); String sql="select * from login

where Name='"+n+"' and Password='"+p+""";

ResultSet rs=stmt.executeQuery(sql);

if(!rs.next())

{

out.println("<html><head></Title> Login error </Title> </head><body>");

out.println("<br><br><br><br><b>Unknown User </b> <br><br> :");

out.println("<h3>Access denied </h3></body></html>");

}

else

{

out.println("<html><head></Title> Login success </Title>

</head><body><center>");

out.println("<br><br><br> Welcome");

out.println(n+"</b><br>");

out.println("<h3>You have been Authenticated </h3> </center>

</body></html>");

}

con.close();

}

catch(SQLException se)

{out.println("Error!!!!"+se); }

catch(ClassNotFoundException cne)

{out.println("Error!!!!"+cne); }

}

} 

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