Introduction In this article, I’m going to explain what is the purpose of the JPA persistence.xml configuration file, and how you can set up a Java Persistence application using the available XML tags or attributes. While Spring applications can bootstrap without needing an XML JPA configuration file, it’s still important to understand the meaning of each configuration option since Spring also offers an alternative way when building a Java Persistence LocalContainerEntityManagerFactoryBean or the Hibernate-specific LocalSessionFactoryBean.