JWS

New spec of JWS uses JAXB 2.0 for JAVA/XML binding. The binding info can be provided in form of annotations on java classes or in external binding file. If annotations have this info then it will be used during deployment and run time. But if the binding information is in external file then it will be used only during deployment time and not during execution. 

One good feature of this JWS spec is that if some info is not provided on java classes for exposing them as web service then it will assume defaults. 

JPA One to Many query

Assume there is a parent entity and has one to many relationship with a child entity. We want to write a query where in a record of parent entity is comapred against each row of its children, we can IN operator.For example 

SELECT e.name, d.name from Department d, IN(d.employees) e where e.salary > 100000

Size in JPA

JPA has a very nice feature wherein we can get the size of rows in a child table.  The EJB QL will be something like this

Select r from Department d where size(d.employees)  > 100