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.
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.MySQL5DialectStep 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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