JPA persistence.xml

Question

Is there a way to make the data on the persistence.xml dynamic? I was thinking of adding a database name property on my properties file, then the tables are created, if not existing.

Is this possible?

I'm using EclipseLink(JPA2.0) and MySQL.

@Bozho: soon I guess... I'm using JPA on my JavaSE to quicken things up... — Cyril Horad, Apr 11 '11 at 12:30

score 3 · Accepted Answer · answered Apr 11 '11 at 12:16

3

If you use JPA in standalone environment, you can pass additional properties to Persistence.createEntityManagerFactory().

In application server environments you can use datasource obtained from JNDI.

answered Apr 11 '11 at 12:16

axtavt

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Can you supply more about the Persistence.createEntityManagerFactory(persitence_name, map_name)? – Cyril Horad Apr 11 '11 at 12:21
@Cyril: The point is that properties from the map override properties from the `persistence.xml`. So, you can pass your dynamic properties via that map. – axtavt Apr 11 '11 at 12:23
And the map should contain the the key of the property name of the persistence.xml exactly? – Cyril Horad Apr 11 '11 at 12:30
@axtavt: If I won't include the classes on the map, would it affect the the classes defined on the persistence.xml? – Cyril Horad Apr 11 '11 at 12:37
@Cyril: That map is only for properties, it doesn't affect classes. – axtavt Apr 11 '11 at 12:46

score 0 · Answer 2 · answered Apr 11 '11 at 12:36

If you are using spring, you can use the spring property-placeholder-configurer mechanism to do so. Just extend your EclipseLink vendor adapter:

public class ExtendedJpaVendorAdapter extends XJpaVendorAdapter {

    private Map<String, Object> vendorProperties;

    @Override
    public Map<String, Object> getJpaPropertyMap() {
        Map<String, Object> properties = super.getJpaPropertyMap();
        properties.putAll(vendorProperties);
        return properties;
    }

    public Map<String, Object> getVendorProperties() {
        return vendorProperties;
    }

    public void setVendorProperties(Map<String, Object> vendorProperties) {
        this.vendorProperties = vendorProperties;
    }

}

And then you can configure these in the spring xml file.

JPA persistence.xml

2 Answers2