Enterprise JavaBeans, Fourth Edition

The ejbCreate( ) Method

ejbCreate( ) methods are called by the container when a client invokes the corresponding create( ) method on the bean’s home. With bean-managed persistence, the ejbCreate( ) methods are responsible for adding new entities to the database. This means that the BMP version of ejbCreate( ) will be much more complicated than the equivalent methods in container-managed entities; with container-managed beans, ejbCreate( ) doesn’t have to do much more than initialize a few fields. Another difference between bean-managed and container-managed persistence is that the EJB specification states that ejbCreate( ) methods in bean-managed persistence must return the primary key of the newly created entity. By contrast, in container-managed beans ejbCreate( ) is required to return null.

The following code contains the ejbCreate( ) method of the ShipBean. Its return type is the Ship EJB’s primary key, Integer. The method uses the JDBC API to insert a new record into the database based on the information passed as parameters:

public Integer ejbCreate(Integer id, String name, int capacity, double tonnage) throws CreateException { if ((id.intValue( ) < 1) || (name == null)) throw new CreateException("Invalid Parameters"); this.id = id; this.name = name; this.capacity = capacity; this.tonnage = tonnage; Connection con = null; PreparedStatement ps = null; try { con = this.getConnection( ); ps = con.prepareStatement( "insert into Ship (id, name, capacity, tonnage) " + "values (?,?,?,?)"); ...