为什么 Hibernate 每次请求都会创建新的数据库连接？

Question

I have Java - Spring Boot - Hibernate - Postgres application. And hibernate creates database connection every request, why? Is there configurable? For example, for one session to last 10 minutes?

My Hibernate configuration:

@Autowired
private Environment environment;

@Bean
public LocalSessionFactoryBean sessionFactory() {
    LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();
    sessionFactory.setDataSource(dataSource());
    sessionFactory.setPackagesToScan(new String[] { "monitoring" });
    sessionFactory.setHibernateProperties(hibernateProperties());
    return sessionFactory;
}

@Bean
public DataSource dataSource() {
    DriverManagerDataSource dataSource = new DriverManagerDataSource();
    dataSource.setDriverClassName("org.postgresql.Driver");
    dataSource.setUrl(environment.getRequiredProperty("spring.datasource.url"));
    dataSource.setUsername(environment.getRequiredProperty("spring.datasource.username"));
    dataSource.setPassword(environment.getRequiredProperty("spring.datasource.password"));
    return dataSource;
}

private Properties hibernateProperties() {
    Properties properties = new Properties();
    properties.put("hibernate.dialect", environment.getRequiredProperty("spring.jpa.properties.hibernate.dialect"));
    properties.put("hibernate.show_sql", environment.getRequiredProperty("spring.jpa.hibernate.show-sql"));
    properties.put("hibernate.format_sql", "false");
    properties.put("hibernate.jdbc.lob.non_contextual_creation", "true");
    return properties;
}

And every request I'm getting following log:

11:19:13.584 [http-nio-8080-exec-2] DEBUG osjdDriverManagerDataSource - Creating new JDBC DriverManager Connection to [jdbc:postgresql://localhost:5432/monit]

Why? How can I change it?

Answer 1

You need to configure connection pools manually since you define a DataSource. From Spring official documentation :

If you define your own DataSource bean, auto-configuration does not occur.

Starting from spring boot 2, HikariCP is the default Connection Pool embedded with spring boot starter ( spring-boot-starter-jdbc and spring-boot-starter-data-jpa ).

You can configure the maximum pool size with the following configuration with HikariCP

spring.datasource.hikari.maximum-pool-size= 10