Override JPA persistence unit properties in code with Google Guice

To override properties from persistence.xml through code while using it with Google guice. One can read the properties from different source and add those properties while installing JpaPersistModule. Following is the sample

1:  Properties persistenceUnit = new Properties();  
2:  persistenceUnit.put("javax.persistence.jdbc.url", "jdbc:mysql://192.168.9.102/MyDB");  
3:  persistenceUnit.put("javax.persistence.jdbc.user", "myuser");  
4:  persistenceUnit.put("javax.persistence.jdbc.password", "mypassword");  
5:  Injector injector = Guice.createInjector(new JpaPersistModule("my-persistence-unit").properties(persistenceUnit));  

One can chose to read this configuration from some other file and install JpaPersistModule with those properties. This could be useful to override database url for test and production.