This post explains the Registration applications in Java using Servlet, JSP, and MySQL database servers. This Java registration form follows Model View Controller (MVC) architecture. Let us understand what is MVC and how this should be used while developing any application.
For Login application in java, refer to the post Login application in Java using MVC
The Model View Controller (MVC) architecture can be best explained with the help of the following diagram.
We are making use of Eclipse Integrated development environment(IDE) for this Java Registration Application. To follow the basic coding standards, I have created my folder structure as shown in the following diagram.
Login Applications in Java:
Any Registration or Login application always begins with views. It can be a page in HTML, JSP, PHP, VB, or any other language. Our Java Registration application begins with Register.jsp and from Register.jsp we will call RegisterServlet.java class.
Register.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Register</title>
<script>
function validate()
{
var fullname = document.form.fullname.value;
var email = document.form.email.value;
var username = document.form.username.value;
var password = document.form.password.value;
var conpassword= document.form.conpassword.value;
if (fullname==null || fullname=="")
{
alert("Full Name can't be blank");
return false;
}
else if (email==null || email=="")
{
alert("Email can't be blank");
return false;
}
else if (username==null || username=="")
{
alert("Username can't be blank");
return false;
}
else if(password.length<6)
{
alert("Password must be at least 6 characters long.");
return false;
}
else if (password!=conpassword)
{
alert("Confirm Password should match with the Password");
return false;
}
}
</script>
</head>
<body>
<center><h2>Java Registration application using MVC and MySQL </h2></center>
<form name="form" action="RegisterServlet" method="post" onsubmit="return validate()">
<table align="center">
<tr>
<td>Full Name</td>
<td><input type="text" name="fullname" /></td>
</tr>
<tr>
<td>Email</td>
<td><input type="text" name="email" /></td>
</tr>
<tr>
<td>Username</td>
<td><input type="text" name="username" /></td>
</tr>
<tr>
<td>Password</td>
<td><input type="password" name="password" /></td>
</tr>
<tr>
<td>Confirm Password</td>
<td><input type="password" name="conpassword" /></td>
</tr>
<tr>
<td><%=(request.getAttribute("errMessage") == null) ? ""
: request.getAttribute("errMessage")%></td>
</tr>
<tr>
<td></td>
<td><input type="submit" value="Register"></input><input
type="reset" value="Reset"></input></td>
</tr>
</table>
</form>
</body>
</html>
RegisterServlet.java
package com.mvc.controller;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.mvc.bean.RegisterBean;
import com.mvc.dao.RegisterDao;
public class RegisterServlet extends HttpServlet {
public RegisterServlet() {
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//Copying all the input parameters in to local variables
String fullName = request.getParameter("fullname");
String email = request.getParameter("email");
String userName = request.getParameter("username");
String password = request.getParameter("password");
RegisterBean registerBean = new RegisterBean();
//Using Java Beans - An easiest way to play with group of related data
registerBean.setFullName(fullName);
registerBean.setEmail(email);
registerBean.setUserName(userName);
registerBean.setPassword(password);
RegisterDao registerDao = new RegisterDao();
//The core Logic of the Registration application is present here. We are going to insert user data in to the database.
String userRegistered = registerDao.registerUser(registerBean);
if(userRegistered.equals("SUCCESS")) //On success, you can display a message to user on Home page
{
request.getRequestDispatcher("/Home.jsp").forward(request, response);
}
else //On Failure, display a meaningful message to the User.
{
request.setAttribute("errMessage", userRegistered);
request.getRequestDispatcher("/Register.jsp").forward(request, response);
}
}
}
To summarize RegisterServlet.java flow :
1. Assign all the inputs(user details) to local variables.
2. Call RegisterBean.java to set all the user details using java setters.
3. Next, go to RegisterDao.java where you are just going to insert user details into the database.
4. Once it is successful, you are displaying a successful message.
RegisterDao.java
Data Access Object – It focuses on business logic with database connections and operations.
Here the RegisterDao.java code makes a connection with the Database layer and inserts user details into the database.
package com.mvc.dao;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import com.mvc.bean.RegisterBean;
import com.mvc.util.DBConnection;
public class RegisterDao {
public String registerUser(RegisterBean registerBean)
{
String fullName = registerBean.getFullName();
String email = registerBean.getEmail();
String userName = registerBean.getUserName();
String password = registerBean.getPassword();
Connection con = null;
PreparedStatement preparedStatement = null;
try
{
con = DBConnection.createConnection();
String query = "insert into users(SlNo,fullName,Email,userName,password) values (NULL,?,?,?,?)"; //Insert user details into the table 'USERS'
preparedStatement = con.prepareStatement(query); //Making use of prepared statements here to insert bunch of data
preparedStatement.setString(1, fullName);
preparedStatement.setString(2, email);
preparedStatement.setString(3, userName);
preparedStatement.setString(4, password);
int i= preparedStatement.executeUpdate();
if (i!=0) //Just to ensure data has been inserted into the database
return "SUCCESS";
}
catch(SQLException e)
{
e.printStackTrace();
}
return "Oops.. Something went wrong there..!"; // On failure, send a message from here.
}
}
RegisterBean.java
JavaBeans are classes that encapsulate many objects into a single object (the bean). A JavaBean property is a named feature that can be accessed by the user of the object. Here the RegisterBean encapsulates registration properties fullName, email, userName, password. To set or access individual properties, set and get functions have been implemented.
package com.mvc.bean;
public class RegisterBean {
private String fullName;
private String email;
private String userName;
private String password;
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public void setFullName(String fullName) {
this.fullName = fullName;
}
public String getFullName() {
return fullName;
}
public void setEmail(String email) {
this.email = email;
}
public String getEmail() {
return email;
}
}
DBConnection.java We are making use of MySQL database server in this application. The URL format and driver name going to be different for different database servers.
package com.mvc.util;
import java.sql.Connection;
import java.sql.DriverManager;
public class DBConnection {
public static Connection createConnection()
{
Connection con = null;
String url = "jdbc:mysql://localhost:3306/customers"; //MySQL URL followed by the database name
String username = "root"; //MySQL username
String password = "root123"; //MySQL password
System.out.println("In DBConnection.java class ");
try
{
try
{
Class.forName("com.mysql.jdbc.Driver"); //loading MySQL drivers. This differs for database servers
}
catch (ClassNotFoundException e)
{
e.printStackTrace();
}
con = DriverManager.getConnection(url, username, password); //attempting to connect to MySQL database
System.out.println("Printing connection object "+con);
}
catch (Exception e)
{
e.printStackTrace();
}
return con;
}
}
web.xml
The web.xml is known as the deployment descriptor. It declares which Servlets exist and which URLs they handle. You need to mention the fully qualified path for Servlet here.
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
<display-name>RegistrationMVC</display-name>
<welcome-file-list>
<welcome-file>Register.jsp</welcome-file>
</welcome-file-list>
<servlet>
<description></description>
<display-name>RegisterServlet</display-name>
<servlet-name>RegisterServlet</servlet-name>
<servlet-class>com.mvc.controller.RegisterServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>RegisterServlet</servlet-name>
<url-pattern>/RegisterServlet</url-pattern>
</servlet-mapping>
</web-app>
Home.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Home Page</title>
</head>
<body>
<center><h2>Home Page</h2></center>
<b>User Registration Successful</b>
<br></br>
<b>Please <a href="https://krazytech.com/programs/a-login-application-in-java-using-model-view-controllermvc-design-pattern">log-in</a> to continue.</b>
</body>
</html>
The code base can be downloaded from here.
Thank you for your great tutorial!
Do you know how can I get multiple inputs in one field?
For example if I have bean Student with private field String classesRegistered , and the student is registered in more classes. When I print Student I get only one class, not all of them.
Any idea how can I do that? Thanks in advance!
Hi,
It is possible to print all the members of the bean class. You can refer to the below link
https://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/builder/ReflectionToStringBuilder.html
Hello Ravi sir,
I am deploying this project on the togglebox.com for web hosting.
But it is showing me following errors can you help me.
30-Jan-2021 21:07:13.290 SEVERE [http-nio-80-exec-5] org.apache.catalina.core.StandardWrapperValve.invoke Servlet.service() for servlet [RegisterServlet] in context with path [] threw exception
java.lang.NullPointerException
at com.mvc.dao.RegisterDao.registerUser(RegisterDao.java:28)
at com.mvc.controller.RegisterServlet.doPost(RegisterServlet.java:47)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:652)
Hi Deepa,
It should work on any platform.
Are you able to connect to the database? You can validate this by going through debug statements/logs.
Please check whether you are using the same database and table details.
Thank you sir for your reply. Yes I checked the log and I found out that the connection issue for database. I was updating connection string from the two files:
1. AdminReport.jsp(this is page I used to display all the table data on jsp page)
2.DBConnection.java
Also here I am using MyPhpAdmin for mysql database.
also created the database here MyPhpAdmin.
I have just added only one jsp page which is displaying all the names of the users registered.
This AdminReport is just is as the linked from Home page as by Href. So we don’t need to have any issue with web,xml file(config file).
So figured it out after checking this in the log:
In DBConnection.java class
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure.
Lastly I have one question that I have to create the URL for my application after hosting it online (I am using togglebox.com) So 1 url for registration page and another url for adminreport page. So I am deploying the whole project and only copying two urls which will be created during togglebox deployment. Hope this is correct and woud work good. Please let me know what is your feedback on it.
Thank you
Hi Deepa,
I’m glad that it started working for you.
You can have 2 links. No issue with that but if you want the adminreport to be displayed only for the logged-in users then you will have to add a login feature as well. Just think about it. Everything depends on your requirements.
Very Helpful! Thank You!
Thanks there :)
Hello Sir, Why I am facing this error? because of this error I am not able to register data in database.Can you please help me.
java.sql.SQLSyntaxErrorException: Unknown column ‘slNo’ in ‘field list’
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:120)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97)
Unknown column ‘slNo’ – This is because the table structure is not matching with your query. Do check RegisterDao.java class
this happens when field name in db does not match with bean class field name