如何通过在Spring Boot的hibernate配置中仅更改db url来更改运行时的数据库连接？

Question

I am developing a Spring Boot application that uses Spring Data JPA and will need to connect to only url different but other all same database eg jdbc:sqlite:db1.db jdbc:sqlite:db2.db I need to create all datasources in runtime . I read a lot of things about it in stack and spring forums(eg AbstractRoutingDataSource) but all of these tutorials show how to create datasources from .properties configuration or static definition in java bean. It is possible to create many datsources in runtime? How to manage transactions and how to create many sessionFactories? It is possible to use @Transactional annotation? What is the best method to do this? Can someone explain me how to do this 'step by step'?

Answer 1

There are two solutions to this problem but I prefer the first one, the developer uses the second one but this is a violation of spring.

First one: Create Multiple data sources, configure it and use it according to your need here is the best guide to follow: Using multiple data sources with Spring Boot

Second one: Yep you can change database connection at runtime only by changing hibernate.cfg.xml property value at runtime firstly here is a code to write hibernate.cfg.xml file:

<session-factory>
    <!-- Database connection settings -->
    <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
    <property name="connection.url"></property>
    <property name="connection.username"></property>
    <property name="connection.password"></property>
    //other things goes here
</session-factory>

Then you can set property values at runtime like where you want:

Configuration configuration = new Configuration();
configuration.configure();
// <!-- Database connection settings -->
configuration.setProperty("hibernate.connection.url", URL);//Here pass connection url
configuration.setProperty("hibernate.connection.username", USERNAME);//Here your connection username
configuration.setProperty("hibernate.connection.password", PASSWORD);//Here your connection password
SessionFactory sessionFactory = configuration.buildSessionFactory();
//Here your transaction begin