Question

I’m using Hibernate 3.6.7-Final and Spring 3.0.5.

I have entity like this

@Entity
public class Foo {
    @ManyToOne
    private Bar bar;
}

@Entity
public class Bar {
    @Column
    String group;
}

How can I use @Filter in Foo where I want to get all Foo‘s that have Bar with group = :group? This is supposed to be a security constraint.

Tryied just setting @Filter(name = "groupFilter", condition = "group = :group") at the attribute bar fromFoo but it didn’t work. Does hibernate have support for this or Filter only works at entity/collection level? Will I have to change all my HQLs to add this security constraint?

Answer 1

First, you have to create the @FilterDef somewhere (this defines the available parameters, and the default condition), then define the @Filter on a particular class.

Finally, have to enable the filter on the Session object, and set any parameters it requires. Filters are not enabled in hibernate sessions by default. You have to enable the specific ones you want once the session is opened.

See section 19.1 for an example: http://docs.jboss.org/hibernate/orm/3.6/reference/en-US/html/filters.html

@FilterDef(name="groupFilter", parameters={@ParamDef( name="group", type="string" )})
@Filters(
  { @Filter(name="groupFilter", condition="group = :group") }
)
public class ... {
}

Then somewhere in your dao code:

session.enableFilter("groupFilter").setParameter("group", group);

You should not have to touch any hql. Whenn you enable the filter, all classes which have an actual @Filter defined for it will automatically apply the condition.

There are additional ways to do things for collections, and i suggest you read the documentation referenced above for that. But in general, you can provide the @Filter annotation classes and on collection properties.