javax.persistence.criteria
Interface Path<X>

Type Parameters:

X - the type referenced by the path

All Superinterfaces:

Expression<X>, Selection<X>, TupleElement<X>

All Known Subinterfaces:

CollectionJoin<Z,E>, From<Z,X>, Join<Z,X>, ListJoin<Z,E>, MapJoin<Z,K,V>, PluralJoin<Z,C,E>, Root<X>, SetJoin<Z,E>

public interface Path<X>
extends Expression<X>

Represents a simple or compound attribute path from a bound type or collection, and is a "primitive" expression.

Since:

Java Persistence 2.0

getModel

Bindable<X> getModel()

Return the bindable object that corresponds to the path expression.

Returns:

bindable object corresponding to the path

getParentPath

Path<?> getParentPath()

Return the parent "node" in the path or null if no parent.

Returns:

parent

get

<Y> Path<Y> get(SingularAttribute<? super X,Y> attribute)

Create a path corresponding to the referenced single-valued attribute.

Parameters:

attribute - single-valued attribute

Returns:

path corresponding to the referenced attribute

get

<E,C extends java.util.Collection<E>> Expression<C> get(PluralAttribute<X,C,E> collection)

Create a path corresponding to the referenced collection-valued attribute.

Parameters:

collection - collection-valued attribute

Returns:

expression corresponding to the referenced attribute

get

<K,V,M extends java.util.Map<K,V>> Expression<M> get(MapAttribute<X,K,V> map)

Create a path corresponding to the referenced map-valued attribute.

Parameters:

map - map-valued attribute

Returns:

expression corresponding to the referenced attribute

type

Expression<java.lang.Class<? extends X>> type()

Create an expression corresponding to the type of the path.

Returns:

expression corresponding to the type of the path

get

<Y> Path<Y> get(java.lang.String attributeName)

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));
  

Parameters:

attributeName - name of the attribute

Returns:

path corresponding to the referenced attribute

Throws:

IllegalStateException - if invoked on a path that corresponds to a basic type

IllegalArgumentException - if attribute of the given name does not otherwise exist

Generated on 10-February-2011 12:41

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