I'm getting back into the Java world, and I'm trying to configure a new Spring web application with JPA, Hibernate and PostgreSQL.
I have found a lot of older examples with various XML configuration files, and I'm wondering if there is a preferred new way to perform this configuration without relying on XML file authoring.
Some of the things I need to configure are the hibernate sql dialect, driver, etc.
Put the following fragments into a class annotated with @Configuration and @EnableTransactionManagement
Hibernate/JPA (edit the packagesToScan String):
@Bean
public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
em.setDataSource(dataSource());
em.setPackagesToScan(new String[] { "com.XY.model" });
JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
em.setJpaVendorAdapter(vendorAdapter);
em.setJpaProperties(additionalProperties());
return em;
}
Properties additionalProperties() {
Properties properties = new Properties();
properties.setProperty("hibernate.hbm2ddl.auto", "update");
properties.setProperty("hibernate.dialect", "org.hibernate.dialect.PostgreSQL9Dialect");
properties.setProperty("hibernate.show_sql", "true");
return properties;
}
DataSource (edit username, password and host address):
@Bean
public DataSource dataSource() {
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName("org.postgresql.Driver");
dataSource.setUrl("jdbc:postgresql://localhost:port/DB_NAME");
dataSource.setUsername("root");
dataSource.setPassword("");
return dataSource;
}
Transaction Manager:
@Bean
public PlatformTransactionManager transactionManager(EntityManagerFactory emf) {
JpaTransactionManager transactionManager = new JpaTransactionManager();
transactionManager.setEntityManagerFactory(emf);
return transactionManager;
}
If you're gonna use spring, i recommend to use Spring Boot which offers many auto configurations. you can use a application.properties for configuring dialects and stuff:
spring.datasource.url = <jdbcurl>
spring.datasource.username = <username>
spring.datasource.password = <password>
spring.datasource.driver-class-name = org.postgresql.Driver
Spring Boot provides a number of Starter Packages that make easy to add jars to your classpath. These Starter Packages simply provide dependencies that you are likely to need when developing a specific type of application. Since you're developing a possibly web application that requires data access, you should add these to your pom.xml:
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.3.1.RELEASE</version>
</parent>
<properties>
<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.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.postgresql</groupId>
<artifactId>postgresql</artifactId>
</dependency>
</dependencies>
Basically, spring boot tries to guess how you will want to configure your application, based on the jar dependencies that you have added. spring-boot-starter-data-jpa, provides the following key dependencies:
You can explicitly configure JPA settings using spring.jpa.* properties. For example, to create and drop tables you can add the following to your application.properties:
spring.jpa.hibernate.ddl-auto=create-drop
You can read more about spring boot here
application.properties. You can also use YAML files, environment variables and command-line arguments to configure your app.