Spring Boot + Thymeleaf + Spring Data JPA CRUD Example

Hello everyone, In this post we will learn how to develop a  CRUD web application, using Spring Boot, Thymeleaf, Spring Data JPA and H2 Database.



Technologies Used:

  • Java 17
  • Spring Boot 2.7.0
  • Spring Data JPA
  • Thymeleaf template engine
  • Maven 3+
  • Bootstrap 4
  • H2 Database

Project Directory:

Pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 
http://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>
   <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>2.7.0</version>
      <relativePath />
   </parent>
   <artifactId>springboot-thymeleaf-jpa-crud</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <name>springboot-thymeleaf-jpa-crud</name>
   <groupId>springboot-thymeleaf-jpa-crud</groupId>
   <properties>
      <java.version>17</java.version>
   </properties>

   <dependencies>
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-data-jpa</artifactId>
      </dependency>
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-thymeleaf</artifactId>
      </dependency>
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-web</artifactId>
      </dependency>

      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-devtools</artifactId>
         <scope>runtime</scope>
      </dependency>
      <dependency>
         <groupId>com.h2database</groupId>
         <artifactId>h2</artifactId>
         <scope>runtime</scope>
      </dependency>
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-test</artifactId>
         <scope>test</scope>
      </dependency>

      <dependency>
         <groupId>javax.validation</groupId>
         <artifactId>validation-api</artifactId>
      </dependency>
   </dependencies>

   <build>
      <plugins>
         <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
         </plugin>
      </plugins>
   </build>
   <description>Spring Boot + Thymeleaf CRUD</description>
</project>


Create User Entity

package com.knowledgefactory.entity;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "UserTable")
public class User {

   @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY)
   private Long id;

   @Column(name = "firstName")
   private String firstName;

   @Column(name = "lastName")
   private String lastName;

   @Column(name = "email", nullable = false, length = 200)
   private String email;

   public User() {

   }

   public Long getId() {
      return id;
   }

   public void setId(Long id) {
      this.id = id;
   }

   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;
   }

   public String getEmail() {
      return email;
   }

   public void setEmail(String email) {
      this.email = email;
   }

   public User(String firstName, String lastName,
             String email) {
      this.firstName = firstName;
      this.lastName = lastName;
      this.email = email;
   }
}


Create Custom Exception

package com.knowledgefactory.exception;

import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ResponseStatus;

@ResponseStatus(value = HttpStatus.NOT_FOUND)
public class RecordNotFoundException extends Exception {

   private static final long serialVersionUID = 1L;

   public RecordNotFoundException(String message) {
      super(message);
   }

   public RecordNotFoundException
              (String message, Throwable throwable) {
      super(message, throwable);
   }
}


Create User Repository

package com.knowledgefactory.repository;

import java.util.List;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;
import com.knowledgefactory.entity.User;

@Repository
public interface UserRepository 
            extends CrudRepository<User, Long> {

   List<User> findAll();
}


Create UserService

package com.knowledgefactory.service;

import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.knowledgefactory.entity.User;
import com.knowledgefactory.exception.RecordNotFoundException;
import com.knowledgefactory.repository.UserRepository;

@Service
public class UserService {

   @Autowired
   UserRepository repository;

   public List<User> getAllusers() {
      
      List<User> result = repository.findAll();
      if (result.size() > 0) {
         return result;
      } else {
         return new ArrayList<User>();
      }
   }

   public User getUserById(Long id) 
         throws RecordNotFoundException {
      
      Optional<User> user = repository.findById(id);

      if (user.isPresent()) {
         return user.get();
      } else {
         throw new RecordNotFoundException
             ("No user record exist for given id");
      }
   }

   public User createOrUpdateUser(User entity) {
      if (entity.getId() == null) {
         entity = repository.save(entity);

         return entity;
      } else {
         Optional<User> user = repository
                   .findById(entity.getId());

         if (user.isPresent()) {
            User newEntity = user.get();
            newEntity.setEmail(entity.getEmail());
            newEntity.setFirstName
                      (entity.getFirstName());
            newEntity.setLastName
                      (entity.getLastName());

            newEntity = repository.save(newEntity);

            return newEntity;
         } else {
            entity = repository.save(entity);

            return entity;
         }
      }
   }

   public void deleteUserById(Long id) 
          throws RecordNotFoundException {
      
      Optional<User> user = repository.findById(id);

      if (user.isPresent()) {
         repository.deleteById(id);
      } else {
         throw new RecordNotFoundException
              ("No user record exist for given id");
      }
   }
}


Create UserController

package com.knowledgefactory.controller;

import java.util.List;
import java.util.Optional;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import com.knowledgefactory.entity.User;
import com.knowledgefactory.exception.RecordNotFoundException;
import com.knowledgefactory.service.UserService;

@Controller
public class UserController {

   @Autowired
   UserService service;

   @GetMapping({ "/" })
   public String getAllUsers(Model model) {

      List<User> list = service.getAllusers();
      model.addAttribute("users", list);
      return "list-users";
   }

   @GetMapping(path = { "/addOrEdit", "/addOrEdit/{id}" })
   public String editUserById(Model model,
           @PathVariable("id") Optional<Long> id)
                  throws RecordNotFoundException {

      if (id.isPresent()) {
         User entity = service.getUserById(id.get());
         model.addAttribute("user", entity);
      } else {
         model.addAttribute("user", new User());
      }
      return "add-edit-user";
   }

   @GetMapping(path = "/delete/{id}")
   public String deleteUserById(Model model,
         @PathVariable("id") Long id)
               throws RecordNotFoundException {

      service.deleteUserById(id);
      return "redirect:/";
   }

   @PostMapping(path = "/createOrUpdateUser")
   public String createOrUpdateUser(User user) {

      service.createOrUpdateUser(user);
      return "redirect:/";
   }
}



Spring Boot Main Driver

package com.knowledgefactory;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {

   public static void main(String[] args) {
      SpringApplication.run(Application.class, args);
   }
}


View

add-edit-user.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">

<head>
<meta charset="utf-8">
<meta http-equiv="x-ua-compatible" content="ie=edge">
<title>Add User</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet"
 href="https://use.fontawesome.com/releases/v5.4.1/css/all.css">
<link rel="stylesheet"
 href="https://cdn.jsdelivr.net/npm/bootstrap@4.6.1/dist/css/bootstrap.min.css">
<script
 src="https://cdn.jsdelivr.net/npm/jquery@3.6.0/dist/jquery.slim.min.js">
    
</script>
<script
 src="https://cdn.jsdelivr.net/npm/bootstrap@4.6.1/dist/js/bootstrap.bundle.min.js">
</script>
</head>

<body>
    <div class="container my-5">
        <h3 th:if="${user.id != null}">Edit User</h3>
        <h3 th:if="${user.id == null}">Add User</h3>
        <div class="card">
            <div class="card-body">
                <div class="col-md-10">
            <form action="#" th:action="@{/createOrUpdateUser}"
                        th:object="${user}" method="post">
                 <div class="row">
       <div class="form-group col-md-8">
             <label for="name" class="col-form-label"> First Name
                                                 </label> 
               <input type="text" th:field="*{firstName}" 
                   class="form-control" id="firstName" 
                               placeholder="First Name" />
       </div>

       <div class="form-group col-md-8">
               <label for="name" class="col-form-label"> Last Name
                                             </label> 
                <input type="text" th:field="*{lastName}" 
                      class="form-control"
                        id="lastName" placeholder="Last Name" />
       </div>

        <div class="form-group col-md-8">
               <label for="email" class="col-form-label"> Email
                                               </label> 
                <input type="text" th:field="*{email}" 
                          class="form-control" id="email"
                                    placeholder="Email Id" />
        </div>

       <div class="col-md-6">
              <input type="submit" class="btn btn-success" 
                           value=" Submit ">
       </div>

             <input type="hidden" id="id" th:field="*{id}">
                        </div>
                    </form>
                </div>
            </div>
        </div>
    </div>
</body>
</html>


list-users.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">

<head>
<meta charset="utf-8">
<meta http-equiv="x-ua-compatible" content="ie=edge">
<title>All Users</title>
<meta name="viewport" content="width=device-width, initial-scale=1">

<link rel="stylesheet"
 href="https://use.fontawesome.com/releases/v5.4.1/css/all.css">
<link rel="stylesheet"
 href="https://cdn.jsdelivr.net/npm/bootstrap@4.6.1/dist/css/bootstrap.min.css">
<script
 src="https://cdn.jsdelivr.net/npm/jquery@3.6.0/dist/jquery.slim.min.js">
    
</script>
<script
 src="https://cdn.jsdelivr.net/npm/bootstrap@4.6.1/dist/js/bootstrap.bundle.min.js">
    
</script>

</head>

<body>
    <div class="container my-2">
        <div class="card">
            <div class="card-body">
                <div th:switch="${users}" class="container my-5">
                    <p class="my-5">
                <a href="/addOrEdit" class="btn btn-success"> 
                   <i class="fas fa-user-plus ml-2"> Add User </i>
                </a>
                    </p>
                    <div class="col-md-10">
                        <h2 th:case="null">No record found !!</h2>
                        <div th:case="*">
           <table class="table table-striped table-responsive-md">
                                <thead>
                                    <tr>
                                        <th>First Name</th>
                                        <th>Last Name</th>
                                        <th>Email</th>
                                        <th>Edit</th>
                                        <th>Delete</th>
                                    </tr>
                                </thead>
                                <tbody>
                            <tr th:each="user : ${users}">
                             <td th:text="${user.firstName}"></td>
                             <td th:text="${user.lastName}"></td>
                             <td th:text="${user.email}"></td>
              <td><a th:href="@{/addOrEdit/{id}(id=${user.id})}"
                          class="btn btn-warning"> 
                       <i class="fas fa-user-edit ml-2"></i>
                                                   </a></td>
              <td><a th:href="@{/delete/{id}(id=${user.id})}"
                          class="btn btn-danger"> 
                       <i class="fas fa-user-times ml-2"></i>
                                                   </a></td>
                                    </tr>
                                </tbody>
                            </table>
                        </div>
                    </div>
                </div>
            </div>
        </div>
    </div>
</body>
</html>


Download the complete source code - click here                                     

Local Setup and Run the application


Step 1: Download or clone the source code from GitHub to a local machine - Click here


Step 2: mvn clean install


Step 3: Run the Spring Boot application - mvn spring-boot:run


From the browser call the endpoint http://localhost:8080/

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