Multiple Persistence Units in persistence.xml

Question

Hi,
in my session bean I want to read data from two ORACLE-database tables, which are located in two ORACLE-schemas (same ORACLE-instance). So I have defined two datasources, one for each schema. Then I defined two persistence-units in my persistence.xml:
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
     <persistence-unit name="DACC/AEMA">
          <jta-data-source>AEMA</jta-data-source>
     </persistence-unit>
     <persistence-unit name="DACC/ALLGEMEIN">
          <jta-data-source>ALLGEMEIN</jta-data-source>
     </persistence-unit>
</persistence>
In NetWeaver Development Studio this result in the following error:
"2 persistence units are found. Only exactly one persistence unti is supported."
What's the solution here? Of course I could define two session beans. But this would result in two development components (DC) as well, because there is only 1 persistence.xml per DC (is this correct?). I don't think this is a good idea. Any other suggestions?
Kind regards,
Christoph

Answer 1

Hi Christoph,
From a Java EE server perspective there are no issues with multiple PUs in a persistence.xml. This is a limitation of NWDS, or WTP (Dali), to be precise. So, you could try to ignore this error and deploy on the server.
HTH!
\-- Vladimir