# UPDATING data using a Thymeleaf application

Paul Tomoiu

●

Java,

Thymeleaf,

frontend,

web

●

Published 2022-12-03

This tutorial explains to you how we can update data from an Oracle database using a Thymeleaf application.

After that you have to define an interface for creating the session and its implementation:

package com.myproject.hibernate;
 
import org.hibernate.SessionFactory;
 
public interface DbConnection {
     SessionFactory getSessionFactory();
}

package com.myproject.hibernate;
 
import java.util.Properties;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.cfg.Environment;
import org.hibernate.service.ServiceRegistry;
import org.springframework.context.annotation.Profile;
import org.springframework.stereotype.Service;
import com.myproject.models.Emp;
import com.myproject.models.Pozitii;
 
@Service
@Profile("prod")
public class ProdHibernateUtil implements DbConnection{
 
private SessionFactory sessionFactory;
  
@Override
public SessionFactory getSessionFactory() {
     if (sessionFactory == null) {
     try {
         Configuration configuration = new Configuration();
         
         // Hibernate settings equivalent to hibernate.cfg.xml's properties
         Properties settings = new Properties();
         settings.put(Environment.DRIVER, "oracle.jdbc.driver.OracleDriver");
         settings.put(Environment.URL, "jdbc:oracle:thin:@localhost:1521:db11g");
         settings.put(Environment.USER, "proiect");
         settings.put(Environment.PASS, "1");
         settings.put(Environment.DIALECT, "org.hibernate.dialect.Oracle10gDialect");
         settings.put(Environment.SHOW_SQL, "true");
          
         configuration.setProperties(settings);
         configuration.addAnnotatedClass(Pozitii.class);
         configuration.addAnnotatedClass(Emp.class);
         ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
                        .applySettings(configuration.getProperties()).build();
                    sessionFactory = configuration.buildSessionFactory(serviceRegistry);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
            return sessionFactory;
        }
 
}

Info

As you can see, this class creates a session to an Oracle database. Also, you can use profiles or not. In this case I use a profile. If you are not using profiles, the interface is not needed.

Also, you need to create a class for mapping the database table:

package com.myproject.models;
 
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
 
@Entity
@Table(name = "Emp")
public class Emp {
    @Id
    @Column(name = "id")
    private int id;
     
    @Column(name = "name")
    private String name;
     
    @Column(name = "telephone")
    private String telephone;
     
    @Column(name = "salary")
    private String salary;
     
    //id
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
     
    //name
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
     
    //telephone
    public String getTelephone() {
        return telephone;
    }
    public void setTelephone(String telephone) {
        this.telephone = telephone;
    }
     
    //salary
    public String getSalary() {
        return salary;
    }
    public void setSalary(String salary) {
        this.salary = salary;
    }
     
}

Also, you need to create the DAO (Data Access Object) class for that table. In this case you only SELECT & UPDATE data, but in real live you have all the operations (select, insert, update, delete) almost any time.

package com.myproject.dao;

import java.util.List;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;
import com.myproject.hibernate.DbConnection;
import com.myproject.models.Emp;

@Repository
public class EmpDao {
 
    @Autowired
    private DbConnection dbConnection;
     
    public List<emp> getEmp() {
         try (Session session = dbConnection.getSessionFactory().openSession()) {
            return session.createQuery("from Emp", Emp.class).list();
         
        }
    }
 
    public void updateEmp(Emp emp) {
        Transaction transaction = null;
        try (Session session = dbConnection.getSessionFactory().openSession()) {
            // start a transaction
            transaction = session.beginTransaction();
            // save the student object
            session.update(emp);
            // commit transaction
            transaction.commit();
        } catch (Exception e) {
            if (transaction != null) {
                transaction.rollback();
            }
            e.printStackTrace();
        }
    }
}

Here it is the Controller class for my application:

package com.myproject;
 
import java.util.List;
import java.util.Map;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import com.myproject.dao.*;
import com.myproject.models.*;
 
@Controller
public class MainController {
 
   @Autowired
   private EmpDao empDao;
         
    //EMP
    @RequestMapping("/emp")
    public String emp(Map<string, object=""> model) {
 
       List<emp> emp = empDao.getEmp();
       model.put("emp", emp);
 
       return "emp";    
    }
     
    @RequestMapping("/empUpdate")
    public String empDelete(@ModelAttribute(value="emp") Emp emp, Map<string, object=""> model) {
 
       empDao.updateEmp(emp);   
       List<emp> empL = empDao.getEmp();
       model.put("emp", empL);
 
       return "redirect:emp";   
    }
     
    @RequestMapping(value="/empUpdateToEdit", method = RequestMethod.POST)
    public String empUpdateEdit(@ModelAttribute(value="emp") Emp emp, Map<string, object=""> model) {
        model.put("emp", emp);
        return "empUpdate"; 
    }
}

Here it is the Thymeleaf templates (emp.html & empUpdate.html) used for the View part of the MVC:

<html>
 <head>
   <meta charset="ISO-8859-1">
   <link rel="stylesheet" type="text/css" href="./css/bootstrap.min.css">
   <title>Employees</title>
   
   <style>
      div.mytable {
        margin: auto;
        width: 1020px;
        padding: 10px; 
      }
   </style>
 </head>
 <body>
     <div class="mytable">
       <nav aria-label="breadcrumb">
         <ol class="breadcrumb">
           <li class="breadcrumb-item"><a href="/">Home</a></li>
           <li class="breadcrumb-item active" aria-current="page">Employees</li>
         </ol>
       </nav>
     </div>
    
     <table class="table table-striped table-primary">
    
       <thead class="ttop">
       <tr class="table-info">
         <td width="20px"><b> ID</b></td>
         <td><b>NAME</b> </td>
         <td><b>TELEPHONE</b> </td>
         <td><b>SALARY</b> </td>
         <td><b>Operation</b> </td>
       </tr>
       </thead>
       <tbody>
       <tr th:each="empl, iStat : ${emp}" th:style="${iStat.odd}? 'font-weight: normal;'">
    
         <td width="20px" th:text="${empl.id}">
         </td><td th:text="${empl.name}">
       </td><td th:text="${empl.telephone}">
       </td><td th:text="${empl.salary}">
       </td><td>
         <form th:action="@{/empUpdateToEdit}" th:object="${emp}" method="post">
           <input type="hidden" name="id" th:value="${empl.id}">
           <input type="hidden" name="name" th:value="${empl.name}">
           <input type="hidden" name="telephone" th:value="${empl.telephone}">
           <input type="hidden" name="salary" th:value="${empl.salary}">
           <button type="submit">Update</button>
         </form>
       </td>
       </tr>
       </tbody>
     </table>
 </body>
</html>

<html>
 <head>
   <meta charset="ISO-8859-1">
   <link rel="stylesheet" type="text/css" href="../../css/bootstrap.min.css">
   <title>Emp Update</title>
 </head>
 <body>
     <div>
       <form th:action="@{/empUpdate}" th:object="${emp}" method="post">
         <input type="textro" name="id" th:value="${emp.id}" readonly="">
         <input type="text" name="name" th:value="${emp.name}">
         <input type="text" name="telephone" th:value="${emp.telephone}">
         <input type="text" name="salary" th:value="${emp.salary}">
         <button type="submit">UPDATE</button>
       </form>
     </div>
 </body>
</html>

The profile is set when the application starts:

package com.myproject;
 
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.core.env.AbstractEnvironment;
 
@SpringBootApplication
public class MySpringApplication {
 
    public static void main(String[] args) {
 
        System.setProperty(AbstractEnvironment.ACTIVE_PROFILES_PROPERTY_NAME, "prod");
        SpringApplication.run(MySpringApplication.class, args);
    }
}

And here it is the web page when you run the application:

Click on the "Update" button on the second line, and you will see that the row. Remove the last 2 number from the telephone number:

Click on the UPDATE button, and you will see the row updated:

Info

This application uses Hibernate and for this reason, you have to add the following in pom.xml :