javax.persistence.criteria.Path Maven / Gradle / Ivy
// $Id: Path.java 17752 2009-10-15 01:19:21Z [email protected] $
// EJB3 Specification Copyright 2004-2009 Sun Microsystems, Inc.
package javax.persistence.criteria;
import javax.persistence.metamodel.PluralAttribute;
import javax.persistence.metamodel.SingularAttribute;
import javax.persistence.metamodel.Bindable;
import javax.persistence.metamodel.MapAttribute;
/**
* Represents a simple or compound attribute path from a
* bound type or collection, and is a "primitive" expression.
*
* @param the type referenced by the path
* @since Java Persistence 2.0
*/
public interface Path extends Expression {
/**
* Return the bindable object that corresponds to the
* path expression.
*
* @return bindable object corresponding to the path
*/
Bindable getModel();
/**
* Return the parent "node" in the path or null if no parent.
*
* @return parent
*/
Path getParentPath();
/**
* Create a path corresponding to the referenced
* single-valued attribute.
*
* @param attribute single-valued attribute
*
* @return path corresponding to the referenced attribute
*/
Path get(SingularAttribute attribute);
/**
* Create a path corresponding to the referenced
* collection-valued attribute.
*
* @param collection collection-valued attribute
*
* @return expression corresponding to the referenced attribute
*/
> Expression get(PluralAttribute collection);
/**
* Create a path corresponding to the referenced
* map-valued attribute.
*
* @param map map-valued attribute
*
* @return expression corresponding to the referenced attribute
*/
> Expression get(MapAttribute map);
/**
* Create an expression corresponding to the type of the path.
*
* @return expression corresponding to the type of the path
*/
Expression> type();
//String-based:
/**
* Create a path corresponding to the referenced attribute.
*
* Note: Applications using the string-based API may need to
* specify the type resulting from the get operation in order
* to avoid the use of Path variables.
*
*
* For example:
*
* CriteriaQuery<Person> q = cb.createQuery(Person.class);
* Root<Person> p = q.from(Person.class);
* q.select(p)
* .where(cb.isMember("joe",
* p.<Set<String>>get("nicknames")));
*
* rather than:
*
* CriteriaQuery<Person> q = cb.createQuery(Person.class);
* Root<Person> p = q.from(Person.class);
* Path<Set<String>> nicknames = p.get("nicknames");
* q.select(p)
* .where(cb.isMember("joe", nicknames));
*
*
* @param attributeName name of the attribute
*
* @return path corresponding to the referenced attribute
*
* @throws IllegalStateException if invoked on a path that
* corresponds to a basic type
* @throws IllegalArgumentException if attribute of the given
* name does not otherwise exist
*/
Path get(String attributeName);
}