可以尝试下这个:
...
Root<JPAAlbum> albm = cq.from(JPAAlbum.class);
... albm.get(JPAAlbum_.theme) ... ;
由Hibernate自动生成,如下所示
public static volatile SingularAttribute<JPAAlbum, JPATheme> theme;
或者 尝试下:
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<JPAAlbum> cq = cb.createQuery(JPAAlbum.class) ;
Root<JPAAlbum> albm = cq.from(JPAAlbum.class);
cq.where(cb.equal(albm.get(JPAAlbum_.theme).get(JPATheme_.id),
session.getTheme().getId())) ;
堆栈跟踪:
Caused by: java.lang.NullPointerException
at org.hibernate.ejb.criteria.path.AbstractPathImpl.get(AbstractPathImpl.java:138)
at net.wazari.dao.jpa.WebAlbumsDAOBean.getRestrictionToAlbumsAllowed(WebAlbumsDAOBean.java:55)
在JBossEntityManager
for (ManagedType o : em.getMetamodel().getManagedTypes()) {
log.warn("___") ;
for (Object p : o.getAttributes()) {
log.warn(((Attribute)p).getName()) ;
}
}
然而,Hibernate知道我的元模型
log.warn("_+_"+JPAPhoto_.id+"_+_") ;
或者尝试下这个“”
java.lang.NullPointerException
at org.hibernate.ejb.criteria.path.AbstractPathImpl.get(AbstractPathImpl.java:138)
at net.wazari.dao.test.TestMetaModel.foo(TestMetaModel.java:55)
输出
ant compile
or
ant dist
启动JUnit测试net.wazari.dao.test.TestMetaModel
CLASSPATH=`sh runTest.sh` java org.junit.runner.JUnitCore net.wazari.dao.test.TestMetaModel
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