Java tutorial
/** * Copyright 2013 Tommi S.E. Laukkanen * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.bubblecloud.ilves.component.field; import com.vaadin.ui.ComboBox; import org.bubblecloud.ilves.model.Company; import org.bubblecloud.ilves.model.User; import org.bubblecloud.ilves.site.AbstractSiteUI; import javax.persistence.EntityManager; import javax.persistence.TypedQuery; import javax.persistence.criteria.CriteriaBuilder; import javax.persistence.criteria.CriteriaQuery; import javax.persistence.criteria.Expression; import javax.persistence.criteria.Root; /** * Field for selecting group. * * @author Tommi S.E. Laukkanen */ public class UserField extends ComboBox { /** Serial version UID. */ private static final long serialVersionUID = 1L; /** * Default constructor which populates the select with existing customers. */ public UserField() { super(); } @Override public final void attach() { super.attach(); final EntityManager entityManager = ((AbstractSiteUI) getUI().getUI()).getSite().getSiteContext() .getObject(EntityManager.class); final Company company = ((AbstractSiteUI) getUI().getUI()).getSite().getSiteContext() .getObject(Company.class); final CriteriaBuilder queryBuilder = entityManager.getCriteriaBuilder(); final CriteriaQuery<User> criteriaQuery = queryBuilder.createQuery(User.class); final Root<User> root = criteriaQuery.from(User.class); final Expression<Comparable> owner = root.get("owner"); criteriaQuery.where(queryBuilder.equal(owner, company)); criteriaQuery.orderBy(queryBuilder.asc(root.get("owner")), queryBuilder.asc(root.get("lastName")), queryBuilder.asc(root.get("firstName"))); final TypedQuery<User> companyQuery = entityManager.createQuery(criteriaQuery); for (final User user : companyQuery.getResultList()) { addItem(user); } } }