Application.java

package com.thomasvitale;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

import com.thomasvitale.model.Person;
import com.thomasvitale.repository.PersonRepository;

@SpringBootApplication
public class Application implements CommandLineRunner {
  
  @Autowired
  PersonRepository personRepository;

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

  @Override
  public void run(String... arg0) throws Exception {
    
      // Save three Person documents on PostgreSQL
      personRepository.save(new Person("Sheldon", "Cooper"));
      personRepository.save(new Person("Missy", "Cooper"));
      personRepository.save(new Person("Leonard", "Hofstadter"));
      
      // Get all the people
      System.out.println(">>> All the people in the database:");
      personRepository.findAll().forEach(System.out::println);
      
      // Get all the people with a specific last name
      System.out.println(">>> All people with last name = 'Cooper'");
      personRepository.findByLastName("Cooper").forEach(System.out::println);
      
      // Update an individual person
      Person person = personRepository.findByFirstName("Sheldon");
      person.setFirstName("Shelly");
      personRepository.save(person);
      
      // Delete all 
      personRepository.deleteAll();
    
  }
}

jpa.properties

hibernate.connection.username=db-user
hibernate.connection.password=db-password
hibernate.connection.url=jdbc:postgresql://localhost:5432/app
hibernate.connection.driver_class=org.postgresql.Driver
hibernate.dialect=org.hibernate.dialect.PostgreSQLDialect
hibernate.current_session_context_class=thread
hibernate.hbm2ddl.auto=validate
hibernate.show_sql=false
hibernate.format_sql=false

JpaConfig.java

package com.thomasvitale;

import java.util.Properties;

import javax.persistence.EntityManagerFactory;
import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.Environment;
import org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.Database;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@Configuration
@EnableTransactionManagement 
@EnableJpaRepositories(basePackages = "com.thomasvitale.repository")
@PropertySource("classpath:jpa.properties")
public class JpaConfig {
  
  @Autowired
  private Environment env;

  @Bean
  public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
    
    HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
    vendorAdapter.setDatabase(Database.POSTGRESQL);
    vendorAdapter.setGenerateDdl(true);
    
    LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
    em.setDataSource(dataSource());
    em.setPackagesToScan("com.thomasvitale.model");
    em.setJpaVendorAdapter(vendorAdapter);
    em.setJpaProperties(additionalProperties());
 
    return em;
  }
  
  @Bean
  public DataSource dataSource(){
    DriverManagerDataSource dataSource = new DriverManagerDataSource();
    dataSource.setDriverClassName(env.getProperty("hibernate.connection.driver_class"));
    dataSource.setUrl(env.getProperty("hibernate.connection.url"));
    dataSource.setUsername(env.getProperty("hibernate.connection.username"));
    dataSource.setPassword(env.getProperty("hibernate.connection.password"));
    return dataSource;
  }
  
  @Bean
  public PlatformTransactionManager transactionManager(EntityManagerFactory emf){
    JpaTransactionManager transactionManager = new JpaTransactionManager();
    transactionManager.setEntityManagerFactory(emf);
  
    return transactionManager;
  }
  
  @Bean
  public PersistenceExceptionTranslationPostProcessor exceptionTranslation(){
    return new PersistenceExceptionTranslationPostProcessor();
  }

  Properties additionalProperties() {
    Properties properties = new Properties();
    properties.setProperty("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
    properties.setProperty("hibernate.dialect", env.getProperty("hibernate.dialect"));
    properties.setProperty("hibernate.current_session_context_class", env.getProperty("hibernate.current_session_context_class"));
    return properties;
  }

}

Person.java

package com.thomasvitale.model;

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

@Entity
@Table(name = "persons")
public class Person {

  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private Integer id;
  
  private String firstName;
  private String lastName;

  public Person() {
  }

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

  public Integer getId() {
    return id;
  }

  public void setId(Integer 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;
  }

  @Override
  public String toString() {
    return firstName + " " + lastName;
  }
}

PersonRepository.java

package com.thomasvitale.repository;

import java.util.List;

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

import com.thomasvitale.model.Person;

@Repository
public interface PersonRepository extends JpaRepository<Person, Integer> {
  
  public Person findByFirstName(String firstName);
  public List<Person> findByLastName(String lastName);
  
}

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>

  <groupId>com.thomasvitale</groupId>
  <artifactId>Application</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>Application</name>
  <description>Demo application for Spring Data JPA</description>

  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.3.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
  </parent>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>1.8</java.version>
  </properties>

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

    <dependency>
      <groupId>org.postgresql</groupId>
      <artifactId>postgresql</artifactId>
      <scope>runtime</scope>
    </dependency>
  
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
    </dependency>
    
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
    </plugins>
  </build>

</project>