understand the Mysql and Jdbc database connectivity code

understand the Mysql and Jdbc database connectivity code through example.

View Answers

April 9, 2008 at 8:14 PM

See the Given JSP Example Code
-------------------------------

Servletform.html

<html>
<title>registration form</title>

<head>

<script language="JavaScript">

function isProper(string) {

if (!string) return false;
var iChars = "*|,\":<>[]{}`\';()@&$#%";

for (var i = 0; i < string.length; i++) {
if (iChars.indexOf(string.charAt(i)) != -1)
return false;
}
return true;
}
function validateForm(theForm){

if(theForm.firstname.value==""){
//Please enter accountholder
alert("Enter the First Name.");
theForm.firstname.focus();
return false;
}

if (isProper(theForm.firstname.value) == false) {
alert("Please enter a valid First Name.");
theForm.firstname.focus();
return false;
}

if(theForm.firstname.value.length > 20) {
alert("Maximum 20 characters allowed for 'First Name'.")
theForm.firstname.focus() ;
return false;
}

if(theForm.address.value==""){
//Please enter accountholder
alert("Enter the address.");
theForm.address.focus();
return false;
}

if(theForm.email.value==""){
//Please enter accountholder
alert("Enter the E-mail address.");
theForm.email.focus();
return false;
}

if(theForm.contect.value==""){
//Please enter accountholder
alert("Enter the contect number.");
theForm.contect.focus();
return false;
}
return true;
}

</script>
</head>
<body>
<table border="1" width="50%" cellpadding="0" cellspacing="0">
<tr>
<td width="100%">
<h2>Registration form</h2>
<form method="GET" action="DataInsertServletExam" onsubmit="return validateForm(this);">
<table border="1" width="100%" cellspacing="0" cellpadding="0">
<tr>
<td><b>Name:</b></td>
<td><input type="text" name="firstname" size="30"></td>
</tr>
<tr><td><b>Address:</b></td>
<td><input type="text" name="address" size="50"></td>
</tr>
<tr>
<td><b>E-mail:<b></td>
<td><input type="text" name="email" size="30"></td>
</tr>
<tr><td><b>Contect No:</b></td>
<td><input type="text" name="contect" size="30"></td>
</tr>
<tr>
<td> </td>
<td><input type="submit" value="Submit" name="submit">
<input type="reset" value="Reset" name="reset">
</td>

</tr>
</table>
</form>
<p> </p>
</tr>
</td>
</table>
</body>

</html>

web.xml

<?xml version="1.0" encoding="ISO-8859-1"?>

<web-app xmlns="http://java.sun.com/xml/ns/j2ee";
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd";
version="2.4">
<servlet>
<servlet-name>InsertDataExample</servlet-name>
<servlet-class>DataInsertServletExam</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>InsertDataExample</servlet-name>
<url-pattern>/DataInsertServletExam</url-pattern>
</servlet-mapping>

</web-app>

DataInsertServletExam.java

import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class DataInsertServletExam extends HttpServlet{
public void doGet(HttpServletRequest request, HttpServletResponse response)throws
ServletException, IOException{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
Connection con = null;
String url = "jdbc:mysql://localhost:3306/";;
String db = "register";
String driver = "com.mysql.jdbc.Driver";
try{
Class.forName(driver);
con = DriverManager.getConnection(url+db,"root","root");
try{
Statement st = con.createStatement();
String firstname=request.getParameter("firstname");
String address=request.getParameter("address");
String email=request.getParameter("email");
String contect=request.getParameter("contect");
int val = st.executeUpdate("insert regiform values('"+firstname+"','"+address+"','"+email+"','"+contect+"')");
con.close();
out.println("Successfully insert data in database");
}
catch (SQLException ex){
System.out.println("SQL statement is not executed!");
}
}
catch (Exception e){
e.printStackTrace();
}

}
}

April 9, 2008 at 8:29 PM

According to above-mentioned code, you need to create three different files namely
1. Servletform.html
2. web.xml and
3. DataInsertServletExam.java

Once you done with these three files just run your application to see the output.

This Example is a good mix of various Java Technologies such as Servlet, JavaScript and java. You not only learn how to use these java technologies collectively but also you will understand the Mysql and Jdbc database connectivity code through example.