197 words

get(attributeName) - JPA Path's method

Method
javax.persistence.criteria.Path
Path<Y> get(
  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
Since:
JPA 2.0

This documentation page is derived (with some adjustments) from the open source JPA 2 RI (EclipseLink)
and is available under the terms of the Eclipse Public License, v. 1.0 and Eclipse Distribution License, v. 1.0.
Object Relational Mapping (ORM) JPA 2 providers include Hibernate, EclipseLink, TopLink, OpenJPA and DataNucleus.
Object DB is not an ORM JPA implementation but an Object Database for Java with built in JPA 2 support.