Crusader Pyro's Blog: CRUD Application in Netbeans using EJB and JPA with MySQL

This tutorial demonstrates how to make an EJB application in Netbeans using JPA and the database as MYSQL.

This is an example of using CRUD (create, retrieve, update and delete) operations using JPA and MySQL database that follows the MVC architecture. It includes a login page which allows only registered users to login and a home page which has the CRUD features to add, edit, delete and search students from the database.

Before we start with the application we need the following:

Netbeans IDE. Click here to download
MySQL database

Step 1: Create a database called 'mydatabase' using the MySQL workbench and create two tables called 'login' (which will store the usernames and passwords of users who can log in) and 'student' (which will store the details of students) and insert some data into the tables.

Login table

Student table

Step 2: Create a new Java Web Application project and give any name such as 'MyEJBApplication' and select the server as 'Glassfish' (Mostly everything would be present by default)

Step 3: Create a JDBC Connection Pool (Right click on Project name -> New -> Other -> Glassfish(folder) -> JDBC Connection Pool)

Step 4: Select MySQL from the dropdown box as shown below. ( Note the name of the connection pool) - in this case it is 'connectionPool')

Step 5: Provide the host, port (within the URL parameter), username and password of your mysql database as shown below:

Step 6: Create a JDBC Resource (Right click on Project name -> New -> Other -> Glassfish(folder) -> JDBC Resource).

Step 7: Select the JDBC connection pool name you just in created above (step 4) from the drop down box. Provide a JNDI name as shown:

Step 8: Create a Persistence Unit (Right click on Project name -> New -> Other -> Persistence -> Persistence Unit).

Step 9: Provide a name to the Persistence Unit and select the data source name which you gave while creating the JDBC Resource above (step 7). (Note that the table generation strategy is set to 'None')

Step 10: Create 3 JSP Pages namely home.jsp, login.jsp and error.jsp and insert the following codes respectively

home.jsp

	<%@page pageEncoding="UTF-8"%>
	<%@taglib prefix="s" uri="http://java.sun.com/jsp/jstl/core" %>
	<!DOCTYPE html>
	<html>
	<head>
	<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
	<title>JSP Page</title>
	</head>
	<body>

	<h1>Welcome <%=session.getAttribute("loginName")%> </h1>

	<h1>Student Information</h1>
	<form action="./StudentServlet" method="POST">
	<table>
	<tr>
	<td>Student ID</td>
	<td><input type="text" name="studentId" value="${student.studentId}" /></td>
	</tr>
	<tr>
	<td>First Name</td>
	<td><input type="text" name="firstname" value="${student.firstName}" /></td>
	</tr>
	<tr>
	<td>Last Name</td>
	<td><input type="text" name="lastname" value="${student.lastName}" /></td>
	</tr>

	<tr>
	<td colspan="2">
	<input type="submit" name="action" value="Add" />
	<input type="submit" name="action" value="Edit" />
	<input type="submit" name="action" value="Delete" />
	<input type="submit" name="action" value="Search" />
	</td>
	</tr>
	</table>
	</form>
	<br>
	<table border="1">
	<th>ID</th>
	<th>First Name</th>
	<th>Last Name</th>

	<s:forEach items="${allStudents}" var="stud">
	<tr>
	<td>${stud.studentId}</td>
	<td>${stud.firstName}</td>
	<td>${stud.lastName}</td>
	</tr>
	</s:forEach>
	</table>

	</body>
	</html>

view raw home.jsp hosted with ❤ by GitHub

	<%@page pageEncoding="UTF-8"%>
	<!DOCTYPE html>
	<html>
	<body >
	<form method="POST" action="/EJBApplication/LoginServlet">
	<table border="0">
	<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 colspan="2" align="center">
	<input type="submit" value="Login"></td>
	</tr>
	</table>
	</form>
	</body>
	</html>

view raw login.jsp hosted with ❤ by GitHub

error.jsp

	<%@page contentType="text/html" pageEncoding="UTF-8"%>
	<!DOCTYPE html>
	<html>
	<head>
	<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
	<title>JSP Page</title>
	</head>
	<body>
	<h1>Error - <%=request.getAttribute("error")%> </h1>
	</body>
	</html>

view raw error.jsp hosted with ❤ by GitHub

Step 11: Create 3 packages as follows:

Step 11.1: First package com.model and create 2 Entity beans namely 'Login' and 'Student' and insert the following codes respectively.

com.model.Login.java

	/*
	* To change this template, choose Tools \| Templates
	* and open the template in the editor.
	*/
	package com.model;

	import java.io.Serializable;
	import javax.persistence.Column;
	import javax.persistence.Entity;
	import javax.persistence.GeneratedValue;
	import javax.persistence.GenerationType;
	import javax.persistence.Id;
	import javax.persistence.NamedQueries;
	import javax.persistence.NamedQuery;
	import javax.persistence.Table;


	@Entity
	@Table
	@NamedQueries({@NamedQuery(name="Login.getAll",query="SELECT e FROM Login e")})
	public class Login implements Serializable{
	@Id
	@GeneratedValue(strategy=GenerationType.AUTO)
	@Column
	private int userId;
	@Column
	private String userName;
	@Column
	private String password;

	public int getUserId() {
	return userId;
	}

	public void setUserId(int userId) {
	this.userId = userId;
	}

	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;
	}


	}

view raw Login.java hosted with ❤ by GitHub

com.model.Student.java

	/*
	* To change this template, choose Tools \| Templates
	* and open the template in the editor.
	*/
	package com.model;

	import java.io.Serializable;
	import javax.persistence.Column;
	import javax.persistence.Entity;
	import javax.persistence.GeneratedValue;
	import javax.persistence.GenerationType;
	import javax.persistence.Id;
	import javax.persistence.NamedQueries;
	import javax.persistence.NamedQuery;
	import javax.persistence.Table;


	@Entity
	@Table
	@NamedQueries({@NamedQuery(name="Student.getAll",query="SELECT e FROM Student e order by e.studentId")})
	public class Student implements Serializable{
	@Id
	@GeneratedValue(strategy=GenerationType.AUTO)
	@Column
	private int studentId;
	@Column
	private String firstName;
	@Column
	private String lastName;

	public Student(int studentId, String firstName, String lastName) {
	this.studentId = studentId;
	this.firstName = firstName;
	this.lastName = lastName;
	}

	public Student() {
	}

	public int getStudentId() {
	return studentId;
	}

	public void setStudentId(int studentId) {
	this.studentId = studentId;
	}

	public String getFirstName() {
	return firstName;
	}

	public void setFirstName(String firstName) {
	this.firstName = firstName;
	}

	public String getLastName() {
	return lastName;
	}

	public void setLastName(String lastName) {
	this.lastName = lastName;
	}





	}

view raw Student.java hosted with ❤ by GitHub

Step 11.2: Second package com.dao that contains the Session Beans (create by right click on project name -> New -> Session Bean) namely 'LoginDAO' and 'StudentDAO'. ( Both these session beans implement methods from a local interface. Select the 'Local Interface'option while creating the session beans. The LoginDAOLocal and StudentDAOLocal will be automatically created). Add the following respective codes to the session beans and their interfaces appropriately.

com.dao.LoginDAO

	/*
	* To change this license header, choose License Headers in Project Properties.
	* To change this template file, choose Tools \| Templates
	* and open the template in the editor.
	*/

	package com.dao;

	import com.model.Login;
	import java.util.List;
	import javax.ejb.Stateless;
	import javax.persistence.EntityManager;
	import javax.persistence.PersistenceContext;

	/**
	*
	* @author Vedang Rane
	*/
	@Stateless
	public class LoginDAO implements LoginDAOLocal {
	@PersistenceContext
	private EntityManager em;
	@Override
	public boolean checkUser(String userName, String password) {

	List<Login> s = (List<Login>)em.createQuery("select e from Login e where e.userName='"+userName+"' and e.password='"+password+"'").getResultList();
	System.out.println("is list empty ?"+s.isEmpty()+" for the"+userName+" and "+password);

	if(!s.isEmpty())
	return true;
	else
	return false;
	}
	// Add business logic below. (Right-click in editor and choose
	// "Insert Code > Add Business Method")
	}

view raw LoginDAO.java hosted with ❤ by GitHub

com.dao.LoginDAOLocal

	/*
	* To change this license header, choose License Headers in Project Properties.
	* To change this template file, choose Tools \| Templates
	* and open the template in the editor.
	*/

	package com.dao;

	import com.model.Login;
	import javax.ejb.Local;

	/**
	*
	* @author Vedang Rane
	*/
	@Local
	public interface LoginDAOLocal {

	public boolean checkUser(String username, String password);

	}

view raw LoginDAOLocal.java hosted with ❤ by GitHub

com.dao.StudentDAO

	/*
	* To change this template, choose Tools \| Templates
	* and open the template in the editor.
	*/
	package com.dao;


	import com.model.Student;

	import java.util.List;
	import javax.ejb.Stateless;
	import javax.persistence.EntityManager;
	import javax.persistence.PersistenceContext;

	/**
	*
	* @author Joseph
	*/
	@Stateless
	public class StudentDAO implements StudentDAOLocal {
	@PersistenceContext
	private EntityManager em;

	@Override
	public void addStudent(Student student) {
	em.merge(student);
	em.flush();
	}

	@Override
	public void editStudent(Student student) {
	em.merge(student);
	em.flush();
	}
	@Override
	public void deleteStudent(int studentId) {

	em.remove(getStudent(studentId));
	em.flush();
	}

	@Override
	public Student getStudent(int studentId) {
	em.flush();
	return em.find(Student.class, studentId);
	}

	@Override
	public List<Student> getAllStudents() {
	em.flush();
	return em.createNamedQuery("Student.getAll").getResultList();
	}

	}

view raw StudentDAO.java hosted with ❤ by GitHub

com.dao.StudentDAOLocal

	/*
	* To change this template, choose Tools \| Templates
	* and open the template in the editor.
	*/
	package com.dao;


	import com.model.Student;
	import java.util.List;
	import javax.ejb.Local;

	/**
	*
	* @author Joseph
	*/
	@Local
	public interface StudentDAOLocal {

	void addStudent(Student student);

	void editStudent(Student student);

	void deleteStudent(int studentId);

	Student getStudent(int studentId);

	List<Student> getAllStudents();

	}

view raw StudentDAOLocal.java hosted with ❤ by GitHub

Step 11.3: Third package com.controller that contains the servlets namely 'LoginServlet' and 'StudentServlet' and add the following codes respectively.

com.controller.LoginServlet


	package com.controller;

	import com.dao.LoginDAOLocal;


	import java.io.IOException;

	import javax.ejb.EJB;
	import javax.servlet.ServletException;
	import javax.servlet.http.HttpServlet;
	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpServletResponse;
	import javax.servlet.http.HttpSession;

	/**
	*
	* @author Vedang Rane
	*/
	public class LoginServlet extends HttpServlet {

	@EJB
	private LoginDAOLocal loginDao;
	Boolean check=false;

	protected void processRequest(HttpServletRequest request, HttpServletResponse response)
	throws ServletException, IOException {
	response.setContentType("text/html;charset=UTF-8");

	String userName = request.getParameter("userName");
	String password = request.getParameter("password");
	HttpSession session = request.getSession();

	check = loginDao.checkUser(userName,password);
	System.out.println("check is"+check+" "+userName);
	if(check)
	{
	session.setAttribute("loginName", userName);
	request.getRequestDispatcher("home.jsp").forward(request, response);
	}
	else
	{
	request.setAttribute("error", "Wrong Username or Password");
	request.getRequestDispatcher("error.jsp").forward(request, response);
	}
	}

	@Override
	protected void doGet(HttpServletRequest request, HttpServletResponse response)
	throws ServletException, IOException {
	processRequest(request, response);
	}


	@Override
	protected void doPost(HttpServletRequest request, HttpServletResponse response)
	throws ServletException, IOException {
	processRequest(request, response);
	}


	@Override
	public String getServletInfo() {
	return "Short description";
	}// </editor-fold>

	}

view raw LoginServlet.java hosted with ❤ by GitHub

com.controller.StudentServlet


	package com.controller;

	import com.dao.StudentDAOLocal;
	import com.model.Student;
	import java.io.IOException;
	import javax.ejb.EJB;
	import javax.servlet.ServletException;
	import javax.servlet.annotation.WebServlet;
	import javax.servlet.http.HttpServlet;
	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpServletResponse;

	/**
	*
	* @author Joseph
	*/
	@WebServlet(name = "StudentServlet")
	public class StudentServlet extends HttpServlet {
	@EJB
	private StudentDAOLocal studentDao;

	protected void processRequest(HttpServletRequest request, HttpServletResponse response)
	throws ServletException, IOException {
	String action = request.getParameter("action");
	String studentIdStr = request.getParameter("studentId");
	int studentId=0;
	if(studentIdStr!=null && !studentIdStr.equals("")){
	studentId=Integer.parseInt(studentIdStr);
	}
	String firstname = request.getParameter("firstname");
	String lastname = request.getParameter("lastname");


	Student student = new Student(studentId, firstname, lastname);

	if("Add".equalsIgnoreCase(action)){
	studentDao.addStudent(student);
	}else if("Edit".equalsIgnoreCase(action)){
	studentDao.editStudent(student);
	}else if("Delete".equalsIgnoreCase(action)){
	studentDao.deleteStudent(studentId);
	}else if("Search".equalsIgnoreCase(action)){
	student = studentDao.getStudent(studentId);
	}
	request.setAttribute("student", student);
	request.setAttribute("allStudents", studentDao.getAllStudents());

	request.getRequestDispatcher("home.jsp").forward(request, response);

	}


	@Override
	protected void doGet(HttpServletRequest request, HttpServletResponse response)
	throws ServletException, IOException {
	processRequest(request, response);
	}


	@Override
	protected void doPost(HttpServletRequest request, HttpServletResponse response)
	throws ServletException, IOException {
	processRequest(request, response);
	}


	@Override
	public String getServletInfo() {
	return "Short description";
	}// </editor-fold>
	}

view raw StudentServlet.java hosted with ❤ by GitHub

Step 12: Check your configuration files(web.xml, persistence.xml and glassfish-resources.xml). They should be as follows:

web.xml

	<?xml version="1.0" encoding="UTF-8"?>
	<web-app version="3.1" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd">
	<welcome-file-list>
	<welcome-file>login.jsp</welcome-file>
	</welcome-file-list>
	<servlet>
	<servlet-name>StudentServlet</servlet-name>
	<servlet-class>com.controller.StudentServlet</servlet-class>
	</servlet>
	<servlet>
	<servlet-name>LoginServlet</servlet-name>
	<servlet-class>com.controller.LoginServlet</servlet-class>
	</servlet>
	<servlet-mapping>
	<servlet-name>StudentServlet</servlet-name>
	<url-pattern>/StudentServlet</url-pattern>
	</servlet-mapping>
	<servlet-mapping>
	<servlet-name>LoginServlet</servlet-name>
	<url-pattern>/LoginServlet</url-pattern>
	</servlet-mapping>
	<session-config>
	<session-timeout>
	30
	</session-timeout>
	</session-config>
	</web-app>

view raw web.xml hosted with ❤ by GitHub

persistence.xml

	<?xml version="1.0" encoding="UTF-8"?>
	<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
	<persistence-unit name="EJBApplicationPU" transaction-type="JTA">
	<jta-data-source>jdbc/myEJBApplicationREsource</jta-data-source>
	<exclude-unlisted-classes>false</exclude-unlisted-classes>
	<properties/>
	</persistence-unit>
	</persistence>

view raw persistence.xml hosted with ❤ by GitHub

glassfish-resources.xml

	<?xml version="1.0" encoding="UTF-8"?>
	<!DOCTYPE resources PUBLIC "-//GlassFish.org//DTD GlassFish Application Server 3.1 Resource Definitions//EN" "http://glassfish.org/dtds/glassfish-resources_1_5.dtd">
	<resources>
	<jdbc-resource enabled="true" jndi-name="jdbc/myEJBApplicationREsource" object-type="user" pool-name="connectionPool">
	<description/>
	</jdbc-resource>
	<jdbc-connection-pool allow-non-component-callers="false" associate-with-thread="false" connection-creation-retry-attempts="0" connection-creation-retry-interval-in-seconds="10" connection-leak-reclaim="false" connection-leak-timeout-in-seconds="0" connection-validation-method="auto-commit" datasource-classname="com.mysql.jdbc.jdbc2.optional.MysqlDataSource" fail-all-connections="false" idle-timeout-in-seconds="300" is-connection-validation-required="false" is-isolation-level-guaranteed="true" lazy-connection-association="false" lazy-connection-enlistment="false" match-connections="false" max-connection-usage-count="0" max-pool-size="32" max-wait-time-in-millis="60000" name="connectionPool" non-transactional-connections="false" ping="false" pool-resize-quantity="2" pooling="true" res-type="javax.sql.DataSource" statement-cache-size="0" statement-leak-reclaim="false" statement-leak-timeout-in-seconds="0" statement-timeout-in-seconds="-1" steady-pool-size="8" validate-atmost-once-period-in-seconds="0" wrap-jdbc-objects="false">
	<property name="URL" value="jdbc:mysql://localhost:3306/mydatabase"/>
	<property name="User" value="root"/>
	<property name="Password" value="vedang123"/>
	</jdbc-connection-pool>
	</resources>

view raw gassfish-resources.xml hosted with ❤ by GitHub

Step 13: The final directory structure of the entire project should look as follows:

Step 14: Run the application by Right click on the project name -> Run

14.a: You should see login.jsp. Provide the username as 'admin' and password as 'admin' (as given in the login table in mydatabase) and click on Login.

14.b: You can now add, edit, delete or search for student records from the student table.

Notes:

The Java Persistence API (JPA) is one possible approach to ORM. JPA is a specification and several implementations are available. Popular implementations are Hibernate, EclipseLink and Apache OpenJPA. (You can check the implementation while creating the persistence.xml configuration file. In this case or by default in netbeans its EclipseLink).
The Entity beans represent the data in the database. Each instance of an entity bean corresponds to a row in the table. Session beans contain the actual business logic methods.

11 comments:

Anonymous30 July 2014 at 09:37
Thanks for this article :)

y tế sức khỏe và đời sống -- Máy đo đường huyết giá rẻ
Unknown26 September 2015 at 06:28
Thanks bro
acamue19 October 2015 at 02:20
hello, i have that problem:
In-place deployment at C:\Users\Camue\Documents\NetBeansProjects\MyEJBApplication\build\web
GlassFish Server 4.1, deploy, null, false
C:\Users\Camue\Documents\NetBeansProjects\MyEJBApplication\nbproject\build-impl.xml:1045: The module has not been deployed.
See the server log for details.
BUILD FAILED (total time: 6 seconds)

please help
Anonymous30 November 2015 at 10:14
Where can download this entire project?
Please could make available for download?
thank you
Unknown3 December 2015 at 04:54
Could you please send a project for me??
fer.elias1@gmail.com
Unknown28 December 2016 at 12:37
hello I need Your help please ! Ihave this error :
Starting GlassFish Server 4.1.1
GlassFish Server 4.1.1 is running.
In-place deployment at C:\Users\user\Desktop\khadidja\AKHER_AMAL\AKHER_AMAL-war\build\web
GlassFish Server 4.1.1, deploy, null, false
C:\Users\user\Desktop\khadidja\AKHER_AMAL\AKHER_AMAL-war\nbproject\build-impl.xml:1076: The module has not been deployed.
See the server log for details.
BUILD FAILED (total time: 1 minute 20 seconds)

Unknown19 January 2020 at 02:37
thanks bro. But after entering username an password to login I get an error which says "The server encountered an internal error that prevented it from fulfilling this request." what do I do?
pcs22 July 2020 at 06:58
Do you have full source code on github ?

Pages

Monday, 3 February 2014

CRUD Application in Netbeans using EJB and JPA with MySQL

11 comments: