问题
I'm developping a program that uses JPA, and I deployed it in a single jar. I wish to modify (or ask to the user, in an menú item) the configuration of the connection data with the database server.
It's possible to modify the data (user, password, ip) of the server "on the fly"?
(I apologize my bad english)
回答1:
The JPA spec doesn't allow for dynamic modification of persistence-units. Some implementations may provide an implementation-specific way of defining a persistence-unit dynamically. With DataNucleus JPA we do it as per the foot of this page
回答2:
how about making a HashMap<String,Object> containing your options and passing it to Persistence.createEntityManagerFactory("unitName",map)?
From the Docs:
public static EntityManagerFactory createEntityManagerFactory(String persistenceUnitName, Map properties)
Create and return an EntityManagerFactory for the named persistence unit using the given properties.
Source
来源：https://stackoverflow.com/questions/9614385/modify-persistence-xml-on-runtime