从Spring中更改hibernate.connection.url

I am using Hibernate in combination with Spring. As database I am currently using HSQL, which stores its data in a file (like SQLite). The path to the HSQL file is currently hard-coded in the persistence.xml. How can I access and change this value at runtime, so a user can load and save from/to an arbitrary HSQL file?I am using Hibernate in combination with Spring