I'm trying to use the QueryByCriteria API to allow users to build dynamic queries. Basically, I'm presenting them with a drop-down that contains all the tables/column that they're able to search on. Then they're presented a drop-down of expressions (i.e. <, >, =, !=) and finally a text box for the value they want to search for.

I noticed that when querying using Expressions, my "value" must be the same type as the property I'm searching on:

Criteria filter = ses.createCriteria(clazz);

if (expression.equals("=")) {
filter.add(Expression.eq(field, Double.valueOf(value)));
}

List results = filter.list();

If I don't do Double.valueOf() when searching on a Double property, I get a ClassCastException. What's the easiest way to dynamically (at run-time) convert the value to the desired property type?

I'm using Hibernate 2.0.2.

Thanks,

Matt