I've written a full-length Javalobby spotlight article running through the basics of the ActiveObjects ORM. In this article, I've gone into a bit more depth regarding the decisions which went into the API design, as well as the reasoning behind yet another Java ORM.

As a side note, I've recently pushed out the version 0.5 release of the framework. It now has a full test suite, as well as some marginally useful javadocing. It's still pre-release, so the public API could potentially change, but at this point the focus has shifted more towards stability (hence the test suite) and documenting.

Another significant goal is benchmarking and improving performance. Since ActiveObjects is an implementation of the Active Record pattern, it's inherently less performant than the relational mapping matter implementations (such as Hibernate) for most scenarios. As such, the framework has to be a bit smarter about how it determines caching and what queries are required. At the moment, AO stands at about 50-60% faster than ActiveRecord for the same operations on the first pass. It's likely this margin would increase on the second pass, since AO has better caching support, as well as the use of PreparedStatements for all queries.

Anyway, I hope y'all enjoy the article, even if you're a die-hard Hibernate fan. Happy databasing!

 new EntityManager( myProvider, true); 

 new EntityManager( myProvider, true); 

@Finder(query="from Customer where firstName = :fn and lastName = :ln")
public Customer findByCustomerName(@Named("fn") firstName, @Named("ln") lastName);

public CustomerFilter extends ExpressionFilter {
    String name;
    Boolean activeOrders;
 
    public CustomerFilter() {
        super(Customer.class);
    }
 
    // setters/getters ellided
    public void buildQuery() {
        if (name != null) {
            // addExpr adds an expression to the filter. These are all ANDed together later in the superclass.
            // eb is an Oracle ExpressionBuilder instance defined in the superclass;
            addExpr(eb.get("name").equal(name));
        }
        if (activeOrders != null) {
            // our booleans are 0/1 in the db -- we didn't bother mapping them as booleans.
            int flag = activeOrders ? 1 : 0;
            addExpr(eb.anyOf("orders").get("active").equal(flag));
        }
        // Result list ordered by name.
        addOrderBy(eb.get("name"));
    }
}

DAOSessionBean sb = lookupDAOBean();
CustomerFilter f = new CustomerFilter();
f.setName("Bob");
List<Customer> result = sb.findByFilter(f);