Thursday, October 12, 2017

CRUD (Create, Read,Update,Delete) operations with Spring Boot , Mysql, JPA , Hibernate with in built Tomcat server.



This post will explain you. How to work with Spring boot and Mysql CRUD(create,read,update,delete) operations
Step 1: Open eclipse and create a java project.. more details please check my previous post getting started with spring boot.

Step 2: create a new pom.xml file under project and the below code to that file.

       

    4.0.0

    org.springframework
    spring_boot_first
    0.1.0

  
        org.springframework.boot
        spring-boot-starter-parent
        1.5.1.RELEASE

 
    
     
                   org.springframework.boot
                   spring-boot-starter-web
            
     
                   org.springframework.boot
                   spring-boot-starter-tomcat
             
      
                    org.springframework.boot
                    spring-boot-starter-security
       
       
                     org.springframework.boot
                     spring-boot-starter-data-jpa
        
                             
                                     org.apache.tomcat
                                     tomcat-jdbc
                              
                        
  
  
                       mysql
                       mysql-connector-java
                
   
                         commons-dbcp
                         commons-dbcp
  
  
    
      
        1.8
    



   


Step 3:Create new model object called User.
 package springboot.model;

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
public class User {
 @Id
 @Column
 private long id;
 @Column
 private String name;
 @Column
 private String gender;
 @Column
 private String country;
 @Column
 private String password;
 
 
 public long getId() {
  return id;
 }
 public void setId(long id) {
  this.id = id;
 }
 public String getName() {
  return name;
 }
 public void setName(String name) {
  this.name = name;
 }
 public String getGender() {
  return gender;
 }
 public void setGender(String gender) {
  this.gender = gender;
 }
 public String getCountry() {
  return country;
 }
 public void setCountry(String country) {
  this.country = country;
 }
 public String getPassword() {
  return password;
 }
 public void setPassword(String password) {
  this.password = password;
 }


}
Step 4: Create UserService and UserServiceImpl under package springboot.service
  package springboot.service;

import java.util.List;

import springboot.model.User;

public interface UserService {

   public List getUsers();
   public List createOrUpdateUser( User user);
   public List deleteUser( User user);
   
 
}
Step 5: Add below code in UserServiceImpl.

  package springboot.service;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import springboot.dao.UserDAO;
import springboot.model.User;

@Component
public class UserServiceImpl implements UserService{

 @Autowired
 private UserDAO userDAO;
 
 @Override
 public List getUsers() {
  return userDAO.getUsers();
 }
 
 public List createOrUpdateUser( User user){
  return userDAO.createOrUpdateUser(user);
 }
   public List deleteUser( User user){
    return userDAO.deleteUser(user);
   }

 public void setUserDAO(UserDAO userDAO) {
  this.userDAO = userDAO;
 }

}



Step 6: Create UserDAO and UserDAOImpl under package springboot.dao as mentioned below
 package springboot.dao;

import java.util.List;

import javax.transaction.Transactional;

import org.springframework.data.repository.CrudRepository;

import springboot.model.User;

@Transactional
public interface UserDAO {
 public List getUsers();
 public List createOrUpdateUser( User user);
 public List deleteUser( User user);

}

Step 7: Add below code inside UserDAOImpl
 package springboot.dao;

import java.util.List;

import org.hibernate.Criteria;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import springboot.model.User;

@Component
public class UserDAOImpl implements UserDAO{
 
 @Autowired
 private SessionFactory sessionFactory;

 public List getUsers(){
  Criteria criteria = sessionFactory.openSession().createCriteria(User.class);
  return criteria.list();
 }
 
 public List createOrUpdateUser( User user){
  Session session = sessionFactory.openSession();
  User oldUser = session.get(User.class, user.getId() );
  //System.out.println("oldUser id["+ oldUser.getId()+"]");
  if(oldUser == null){
   session.save(user);
   session.flush();
   System.out.println("Created or Update Successful");
    }
  Criteria criteria = sessionFactory.openSession().createCriteria(User.class);
  return criteria.list();
 }
 public List deleteUser( User user){
  Session session = sessionFactory.openSession();
  User oldUser = session.get(User.class, user.getId() );
  if(oldUser != null){
   session.delete(oldUser);
   session.flush();
   System.out.println("Deleted successfully");
  }
  Criteria criteria = sessionFactory.openSession().createCriteria(User.class);
  return criteria.list();
 }

 public void setSessionFactory(SessionFactory sessionFactory) {
  this.sessionFactory = sessionFactory;
 }

}

Step 8: Create BeanConfig class. which will create EntityManagerFactory.
 package springboot;

import javax.persistence.EntityManagerFactory;

import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class BeanConfig {

 @Autowired
 private EntityManagerFactory entityManagerFactory;

 @Bean
 public SessionFactory getSessionFactory() {
     if (entityManagerFactory.unwrap(SessionFactory.class) == null) {
         throw new NullPointerException("factory is not a hibernate factory");
     }
     return entityManagerFactory.unwrap(SessionFactory.class);
 }

 public void setEntityManagerFactory(EntityManagerFactory entityManagerFactory) {
  this.entityManagerFactory = entityManagerFactory;
 }

}

Step 9: Now we need to add code related to database details called application.properties
  # ===============================
# = DATA SOURCE
# ===============================

# Set here configurations for the database connection
spring.datasource.url = jdbc:mysql://localhost:3306/employee?useSSL=false

# Username and password
spring.datasource.username = root
spring.datasource.password = root

spring.jpa.show-sql = true
spring.jpa.hibernate.ddl-auto = update
spring.jpa.hibernate.naming-strategy = org.hibernate.cfg.ImprovedNamingStrategy
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect
Step 10: Create a RestController class. Name it as UserController
package springboot;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;

import springboot.model.User;
import springboot.service.UserService;

@Controller
public class UserController {
 
 @Autowired
 private UserService userService;
 
 @RequestMapping(value = "/list", method = RequestMethod.GET)
 public ResponseEntity userDetails() {
        
  List userDetails = userService.getUsers();
  return new ResponseEntity(userDetails, HttpStatus.OK);
 }
 
 @RequestMapping(value = "/create/{id}/{name}/{password}/{gender}/{country}/", method = RequestMethod.GET)
 public ResponseEntity createOrUpdateUserDetails(@PathVariable("id") long id, @PathVariable("name") String name,
   @PathVariable("password") String password,@PathVariable("gender") String gender,@PathVariable("country") String country) {
        User user = new User();
        user.setId(id);
        user.setName(name);
        user.setCountry(country);
        user.setGender(gender);
        user.setPassword(password);
  List userDetails = userService.createOrUpdateUser(user);
  return new ResponseEntity(userDetails, HttpStatus.OK);
 }
 @RequestMapping(value = "/delete/{id}", method = RequestMethod.GET)
 public ResponseEntity deleteUserDetails(@PathVariable("id") long id) {
        User user = new User();
        user.setId(id);
  List userDetails = userService.deleteUser(user);
  return new ResponseEntity(userDetails, HttpStatus.OK);
 }


 public void setUserService(UserService userService) {
  this.userService = userService;
 }

}

Step 11: Now we need to run this application through spring boot. So we have to write Application class.
  package springboot;

import java.util.Arrays;

import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;

@SpringBootApplication
public class Application {

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

    @Bean
    public CommandLineRunner commandLineRunner(ApplicationContext ctx) {
        return args -> {

            System.out.println("Let's inspect the beans provided by Spring Boot:");

            String[] beanNames = ctx.getBeanDefinitionNames();
            Arrays.sort(beanNames);
            for (String beanName : beanNames) {
                System.out.println(beanName);
            }

        };
    }

}


Step 12: Now we need to build and run this application.
Right click on the pom.xml file and Run As - clean install
Once that is done. Right click on the Application.java and Run As-> Java Application. Below details will be printed in Console
     .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.5.1.RELEASE)

2017-10-12 17:17:15.600  INFO 13036 --- [           main] springboot.Application                   : Starting Application on LAPTOP-2U8NKC7I with PID 13036 (F:\eclipse_workspace\spring_boot_first\target\classes started by Siva in F:\eclipse_workspace\spring_boot_first)
2017-10-12 17:17:15.626  INFO 13036 --- [           main] springboot.Application                   : No active profile set, falling back to default profiles: default
2017-10-12 17:17:16.033  INFO 13036 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@23bb8443: startup date [Thu Oct 12 17:17:15 IST 2017]; root of context hierarchy

   

Step 13: Use http://localhost:8080/list -- it will display all the records which is there inside user table.
If it askes username and password - then username will be - user and password will be check Using default security password: in console. that is your password.


Step 14: Use http://localhost:8080/create/16/sanju/sam/M/India/ - it will insert record inside DB and will display all the records from user table.

Step 15 : http://localhost:8080/delete/16 - it will delete where id is 16 and display all the results from user table.

Step 16 : Now we will learn how to create database and create a table.
Step 17: Install mysql and create database with name- employee. and create a table name called User with columns as mentioned below.
     CREATE TABLE user (
  id int(11) NOT NULL,
  name varchar(45) DEFAULT NULL,
  gender varchar(10) DEFAULT NULL,
  password varchar(45) DEFAULT NULL,
  country varchar(45) DEFAULT NULL,
  PRIMARY KEY (`id`)) 
     

Step 18: If you want to use another database. simply change the application.properties respective DB details and dialect along with respective connecter in pom.xml

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