Simple code for Ajax with Hibernate

1. Create one dynamic application in eclipse and add below jar file in class path as well in WEB-INF\lib folder:
antlr-3.1.jar
cglib-nodep-2.1_3.jar
commons-collections-3.2.jar
commons-logging-1.1.jar
dom4j-1.1.jar
hibernate-3.2.5.ga.jar
hibernate-annotations-3.4.0.GA.jar
hibernate-commons-annotations-3.3.0.ga.jar
log4j-1.2.15.jar
mysql-connector-java-3.1.12-bin.jar
persistence-api-1.0.jar
slf4j-api-1.5.10.jar
slf4j-log4j12-1.5.10.jar
transaction-api-1.1.jar

2. Create one servlet Login.java


package com.novell;

import java.io.IOException;
import java.util.List;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.AnnotationConfiguration;



public class Login extends HttpServlet {
private static final long serialVersionUID = 1L;
private SessionFactory sessionFactory = null;
private Session session;
 
    public Login() {
        super();
        sessionFactory  = new AnnotationConfiguration().configure().buildSessionFactory();
       
        System.out.println("IT IS SESSION :"+session);
     }

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("It is get method ..........");
}

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String userName = request.getParameter("userName");
String password = request.getParameter("password");
 HttpSession httpSession = request.getSession();
int userid = checkCredential(userName,password);
if(userid==0){
   httpSession.setAttribute("message", "Your Credential is wrong ........");
 RequestDispatcher rd = request.getRequestDispatcher("login.jsp");
 rd.forward(request, response);
}else{
httpSession.setAttribute("message", "You are welcome ..........");
CalculatorState temp = getCalState(userid);
if(temp == null){
temp = new CalculatorState();
temp.setUserId(userid);
temp.setFirstValue(0);
temp.setSecondValue(0);
}
httpSession.setAttribute("state", temp);
RequestDispatcher rd = request.getRequestDispatcher("ucalc.jsp");
rd.forward(request, response);
}

}

private int checkCredential(String userName, String password){
session =sessionFactory.openSession();
List users = session.createQuery("from User where userName = '"+userName+"' and password= '"+password+"'").list();
session.close();
if(users.size()>0){return users.get(0).getId();}
else{return 0;}
}

private CalculatorState getCalState(int id){
session =sessionFactory.openSession();
List calculatorState = session.createQuery("from CalculatorState where userId = "+id).list();
System.out.println("Size of state POJO :"+calculatorState.size());
session.close();
if(calculatorState.size()==0){return null;}
else {return calculatorState.get(0);}

}

}

3. Other Servlet : Calculator.java

package com.novell;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.logging.Logger;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;



import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.AnnotationConfiguration;



public class Calculator extends HttpServlet {
private static Logger logger = Logger.getLogger(Calculator.class.getName());
private static final long serialVersionUID = 1L;
Map stragetyMap = new HashMap();
    private SessionFactory sessionFactory = null;
  private Session session;


    public Calculator() {
        super();
        sessionFactory  = new AnnotationConfiguration().configure().buildSessionFactory();
        logger.info("Servlet constructor is calling ...........");
        stragetyMap.put("add", new MainStrategy(new AddCalc()));
        stragetyMap.put("sub", new MainStrategy(new SubCalc()));
        stragetyMap.put("multi", new MainStrategy(new MultiCalc()));
        stragetyMap.put("div", new MainStrategy(new DivideCalc()));
       
    }

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
logger.info("Hitting to server ............");
String first = request.getParameter("first");
String second = request.getParameter("second");
String operation = request.getParameter("operation");
String useridUI = request.getParameter("userid");
logger.info("First Number :"+first);
logger.info("Second Number :"+second);
logger.info("User id :"+useridUI);
saveLatestData(useridUI,first,second);
// int result = calculation(Integer.parseInt(first),Integer.parseInt(second),operation);
int result = ((MainStrategy)stragetyMap.get(operation)).cal(Integer.parseInt(first),Integer.parseInt(second));
saveLatestData(useridUI,first,result+"");
response.setContentType("text/html");
response.getWriter().write(result+"");
}
 
/*public int calculation(int first,int second,String operation){
MainStrategy mainStrategy = null;
if(operation.equals("add")){mainStrategy = new MainStrategy(new AddCalc());}
if(operation.equals("sub")){mainStrategy = new MainStrategy(new SubCalc());}
if(operation.equals("multi")){mainStrategy = new MainStrategy(new MultiCalc());}
if(operation.equals("div")){mainStrategy = new MainStrategy(new DivideCalc());}
return mainStrategy.cal(first, second);
}*/

private void saveLatestData(String useridUI,String first,String second){
int firstNumber  = Integer.parseInt(first);
int secondNumber = Integer.parseInt(second);
int id = Integer.parseInt(useridUI);
CalculatorState cs = new CalculatorState();
cs.setUserId(id);
cs.setFirstValue(firstNumber);
cs.setSecondValue(secondNumber);
updateCalState(cs);
}

private void updateCalState(CalculatorState cs){
try{
session =sessionFactory.openSession();
Transaction transaction = session.beginTransaction();
session.saveOrUpdate(cs);
transaction.commit();
session.flush();
   session.close();
}catch(Exception e){
e.printStackTrace();
System.out.println("Some issue while saving new data .......");
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
logger.info("It is Post Method ............");
doGet(request,response);
}

}

4. login.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>Calculator Login</title>

<script src="jquery.js"></script>

<script src="login.js" type="text/javascript"></script>

</head>

<body>

<h2>Please login to open your calculator</h2>

<%

 String message = (String)session.getAttribute("message");

 if(message!=null){

  out.println(message);

 }

%>

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

<table>

<tr><td>Please Enter User Name :</td><td><input type="text" id="userName" name="userName" /></td></tr>

<tr><td>Please Enter Password  :</td><td><input type="password" id="password" name="password"/></td></tr>

<tr><td><input type="submit" id="loginButtonSubmit" value="Submit"/></td><td><input type="button" value="Clear" id="clear"/></td></tr>

</table>

</form>

</body>

</html>

5. ucalc.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>Simple Calculator</title>

<script type="text/javascript" src="ucal.js"></script>

<jsp:useBean id="state" class="com.novell.CalculatorState" scope="session"/>

</head>

<body>

It is simple Calculator

<br>

<input type="hidden" id="hiddenId" value="${state.userId}"/>

<input type="text" id="firstNumber" value="${state.firstValue}"/>

<input type="button" id="addButton" value="Add" onclick="addAction()"/>

<input type="text" id="secondNumber" readonly="readonly" value="${state.secondValue}"/>

<input type="button" id="clearButton" value="Clear" onclick="clearInput()"/>

</body>

</html>

6. ucal.js

var request;

function getRequest(){

      if(window.ActiveXObject){

        request = new ActiveXObject("Microsoft.XMLHTTP"); 

       }else if(window.XMLHttpRequest){

        request = new XMLHttpRequest(); 

      } 

    }

function addAction(){

 var first = document.getElementById("firstNumber").value;

 if(first==null||first==""){

alert("Please enter first number");

return null;

 }

 var second = document.getElementById("secondNumber").value;

 if(second==null||second==""){

second = 0;

 }

 var id = document.getElementById("hiddenId").value;

 //alert("Id :"+id);

 calculation(first, second, "add",id);

}

function calculation(first, second, operation,userid){

 getRequest();

 var url = "http://localhost:8080/Calculator/Calculator?first="+first+"&second="+second+"&operation="+operation+"&userid="+userid;

 //alert(url);

 request.open("POST",url,false);

 request.onreadystatechange = showResult;

 request.send();

}

function calculation2(first, second, operation){

getRequest();

var url = "http://localhost:8080/Calculator/Calculator";

     request.open("POST",url,false);

request.onreadystatechange = showResult;

request.setRequestHeader("Content-type","application/x-www-form-urlencoded");

request.send("first="+first+"&second="+second+"&operation="+operation); // Why Null

 }

function showResult(){

if(request.readyState == 4){

        var result = request.responseText;

        document.getElementById("secondNumber").value = result;

   }

}

function clearInput(){

document.getElementById("firstNumber").value="";

document.getElementById("secondNumber").value="";

}

7. User.java

package com.novell;

public class User {

private int id;

private String userName;

private String password;

 

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

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;

}

 

 

}

8. CalculatorState.java

package com.novell;

public class CalculatorState {

private int userId;

private int firstValue;

private int secondValue;

public int getUserId() {

return userId;

}

public void setUserId(int userId) {

this.userId = userId;

}

public int getFirstValue() {

return firstValue;

}

public void setFirstValue(int firstValue) {

this.firstValue = firstValue;

}

public int getSecondValue() {

return secondValue;

}

public void setSecondValue(int secondValue) {

this.secondValue = secondValue;

}

}

9. Cal.hbm.xml

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >

<hibernate-mapping>

<class name="com.novell.CalculatorState" table="calculator">

<id name="userId" column="id">

<generator class="assigned" />

</id>

<!-- Both property are optional here as property name and column name are same -->

<property name="firstValue" column="firstValue" />

<property name="secondValue" column="secondValue" />

</class>

</hibernate-mapping>

10. User.hbm.xml

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >

<hibernate-mapping>

<class name="com.novell.User" table="login">

<id name="id" column="id">

<generator class="increment" />

</id>

<!-- Both property are optional here as property name and column name are same -->

<property name="userName" column="userName" />

<property name="password" column="password" />

</class>

</hibernate-mapping>

11. hibernate.cfg.xml

<?xml version='1.0' encoding='UTF-8'?>

<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"          

"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

<session-factory>

<property name="connection.url">jdbc:mysql://localhost/sumandb</property>

<property name="connection.driver_class">com.mysql.jdbc.Driver</property>

<property name="dialect">org.hibernate.dialect.MySQLDialect</property>

<property name="connection.username">root</property>

<property name="connection.password">mysql</property>

<property name="transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</property>

<!-- this will show us all sql statements -->

<property name="hibernate.show_sql">true</property>

<!-- mapping files -->

<mapping resource="Cal.hbm.xml" />

<mapping resource="User.hbm.xml" />

</session-factory>

</hibernate-configuration>