question: @ SuppressWarnings ( { "cast" , "unchecked" } ) public List < DeviceInfo > listDeviceInfo ( ) { EntityManager mgr = getEntityManager ( ) ; List < DeviceInfo > result = new ArrayList < DeviceInfo > ( ) ; try { Query query = mgr . createQuery ( "select from DeviceInfo" ) ; for ( Object obj : ( List < Object > ) query . getResultList ( ) ) { result . add ( ( ( DeviceInfo ) obj ) ) ; } } finally { mgr . close ( ) ; } return result ; }
target:  This method lists all the entities inserted in datastore. It uses HTTP GET method.