<dependencies>
...
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>5.3.9</version>
</dependency>
...
</dependencies>
properties
spring.datasource.url=jdbc:mysql://localhost:3306/mydb
spring.datasource.username=username
spring.datasource.password=password
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
<context:component-scan base-package="com.example" />
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="url" value="${spring.datasource.url}" />
<property name="username" value="${spring.datasource.username}" />
<property name="password" value="${spring.datasource.password}" />
<property name="driverClassName" value="${spring.datasource.driver-class-name}" />
</bean>
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="packagesToScan" value="com.example.entity" />
<property name="jpaProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQL8Dialect</prop>
<prop key="hibernate.hbm2ddl.auto">update</prop>
<prop key="hibernate.show_sql">true</prop>
</props>
</property>
</bean>
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>
<tx:annotation-driven />
</beans>
import javax.persistence.*;
@Entity
@Table(name = "users")
public class User {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
private int age;
}
public interface UserDao {
User findById(Long id);
List<User> findAll();
void save(User user);
void update(User user);
void delete(User user);
}
import org.springframework.stereotype.Repository;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import java.util.List;
@Repository
public class UserDaoImpl implements UserDao {
@PersistenceContext
private EntityManager entityManager;
@Override
public User findById(Long id) {
return entityManager.find(User.class, id);
}
@Override
public List<User> findAll() {
String jpql = "SELECT u FROM User u";
return entityManager.createQuery(jpql, User.class).getResultList();
}
@Override
public void save(User user) {
entityManager.persist(user);
}
@Override
public void update(User user) {
entityManager.merge(user);
}
@Override
public void delete(User user) {
entityManager.remove(user);
}
}
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import java.util.List;
@Controller
@RequestMapping("/users")
public class UserController {
@Autowired
private UserDao userDao;
@RequestMapping("/")
@ResponseBody
public String index() {
List<User> users = userDao.findAll();
StringBuilder sb = new StringBuilder();
for (User user : users) {
sb.append(user.getName()).append(", ");
}
return sb.toString();
}
}
