Java tutorial
/** * 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.deephacks.confit.internal.jpa; import com.google.common.base.Objects; import com.google.common.base.Optional; import com.google.common.collect.Multimap; import com.google.common.collect.Sets; import org.deephacks.confit.model.Bean; import org.deephacks.confit.model.BeanId; import org.deephacks.confit.model.ThreadLocalManager; import javax.persistence.EmbeddedId; import javax.persistence.Entity; import javax.persistence.EntityManager; import javax.persistence.NamedQueries; import javax.persistence.NamedQuery; import javax.persistence.NoResultException; import javax.persistence.Query; import javax.persistence.Table; import javax.persistence.Transient; import java.io.Serializable; import java.util.ArrayList; import java.util.HashSet; import java.util.List; import java.util.Set; import static com.google.common.base.Objects.equal; import static com.google.common.base.Objects.toStringHelper; import static org.deephacks.confit.internal.jpa.JpaProperty.deletePropertiesAndMarker; /** * JpaBean is a jpa entity that represent a Bean. * * @author Kristoffer Sjogren */ @Entity @Table(name = "CONFIG_BEAN") @NamedQueries({ @NamedQuery(name = JpaBean.FIND_BEAN_FROM_BEANID_NAME, query = JpaBean.FIND_BEAN_FROM_BEANID), @NamedQuery(name = JpaBean.FIND_BEANS_FROM_SCHEMA_NAME, query = JpaBean.FIND_BEANS_FROM_SCHEMA), @NamedQuery(name = JpaBean.DELETE_BEAN_USING_BEANID_NAME, query = JpaBean.DELETE_BEAN_USING_BEANID) }) public class JpaBean implements Serializable { private static final long serialVersionUID = -4097243985344046349L; @EmbeddedId private JpaBeanPk pk; public static List<Bean> findEager(Set<BeanId> ids) { if (ids.size() == 0) { return new ArrayList<>(); } JpaBeanQueryAssembler query = new JpaBeanQueryAssembler(ids); // collect references recursively collectRefs(ids, query, 10); // fetch properties for list beans at once List<JpaProperty> allProperties = JpaProperty.findProperties(query.getIds()); query.addProperties(allProperties); return query.assembleBeans(); } public static Bean findEager(BeanId id) { List<Bean> beans = findEager(Sets.newHashSet(id)); if (beans == null || beans.size() == 0) { return null; } return beans.get(0); } public static List<Bean> findEager(List<BeanId> ids) { /** * TODO: Need to take care of BeanId that may apear more than once in 'ids'. */ return findEager(Sets.newHashSet(ids)); } private static void collectRefs(Set<BeanId> predecessors, JpaBeanQueryAssembler query, int level) { if (--level < 0) { return; } Multimap<BeanId, JpaRef> successors = JpaRef.findReferences(predecessors); if (successors.size() > 0) { query.addRefs(predecessors); } // only recurse successors we havent already visited to break circular references Set<BeanId> unvisitedSuccessors = new HashSet<>(); for (JpaRef successor : successors.values()) { if (!query.contains(successor.getTarget())) { unvisitedSuccessors.add(successor.getTarget()); } } if (unvisitedSuccessors.size() != 0) { // we have reached the end and found list successors collectRefs(unvisitedSuccessors, query, level); } query.addRefs(successors); } /** * Finds the provided beans and initalize their properties and direct * references (but no further). */ public static List<Bean> findLazy(Set<BeanId> ids) { if (ids.size() == 0) { return new ArrayList<>(); } JpaBeanQueryAssembler query = new JpaBeanQueryAssembler(ids); List<JpaProperty> allProperties = JpaProperty.findProperties(query.getIds()); query.addProperties(allProperties); Multimap<BeanId, JpaRef> refs = JpaRef.findReferences(ids); if (refs.size() > 0) { query.addRefs(refs); } return query.assembleBeans(); } protected static final String FIND_BEANS_FROM_SCHEMA = "SELECT DISTINCT e FROM JpaBean e WHERE e.pk.schemaName= ?1 ORDER BY e.pk.id"; protected static final String FIND_BEANS_FROM_SCHEMA_NAME = "FIND_BEANS_FROM_SCHEMA_NAME"; @SuppressWarnings("unchecked") public static List<Bean> findEager(String schemaName) { Optional<EntityManager> em = getEm(); if (!em.isPresent()) { return new ArrayList<>(); } Query query = em.get().createNamedQuery(FIND_BEANS_FROM_SCHEMA_NAME); query.setParameter(1, schemaName); List<JpaBean> beans = (List<JpaBean>) query.getResultList(); Set<BeanId> ids = new HashSet<>(); for (JpaBean jpaBean : beans) { ids.add(jpaBean.getId()); } return findEager(ids); } /** * Will return the target bean and its direct predecessors for validation */ public static Set<Bean> getBeanToValidate(Set<BeanId> ids) { List<JpaRef> targetPredecessors = JpaRef.getDirectPredecessors(ids); Set<BeanId> beansToValidate = new HashSet<>(); for (JpaRef ref : targetPredecessors) { beansToValidate.add(ref.getSource()); } beansToValidate.addAll(ids); JpaBeanQueryAssembler query = new JpaBeanQueryAssembler(beansToValidate); collectRefs(beansToValidate, query, 2); List<JpaProperty> allProperties = JpaProperty.findProperties(query.getIds()); query.addProperties(allProperties); return new HashSet<>(query.assembleBeans()); } protected static final String FIND_BEAN_FROM_BEANID = "SELECT DISTINCT e FROM JpaBean e WHERE e.pk.id = ?1 AND e.pk.schemaName= ?2"; protected static final String FIND_BEAN_FROM_BEANID_NAME = "FIND_BEAN_FROM_BEANID_NAME"; public static boolean exists(BeanId id) { Query query = getEmOrFail().createNamedQuery(FIND_BEAN_FROM_BEANID_NAME); query.setParameter(1, id.getInstanceId()); query.setParameter(2, id.getSchemaName()); try { query.getSingleResult(); } catch (NoResultException e) { return false; } return true; } /** * Need not consult the JpaBean table since the property marker * in JpaProperties table is an indicator that the JpaBean really * exist, even if it has no properties. */ @SuppressWarnings("unused") private static JpaBean getJpaBeanAndProperties(BeanId id) { List<JpaProperty> props = JpaProperty.findProperties(id); if (props.size() == 0) { // no marker, bean does not exist return null; } JpaBean bean = new JpaBean(new JpaBeanPk(id)); JpaProperty.filterMarkerProperty(props); bean.properties.addAll(props); return bean; } protected static final String DELETE_BEAN_USING_BEANID = "DELETE FROM JpaBean e WHERE e.pk.id = ?1 AND e.pk.schemaName= ?2"; protected static final String DELETE_BEAN_USING_BEANID_NAME = "DELETE_BEAN_USING_BEANID_NAME"; public static Bean deleteJpaBean(BeanId id) { Bean bean = findEager(id); deletePropertiesAndMarker(id); JpaRef.deleteReferences(id); Query query = getEmOrFail().createNamedQuery(DELETE_BEAN_USING_BEANID_NAME); query.setParameter(1, id.getInstanceId()); query.setParameter(2, id.getSchemaName()); query.executeUpdate(); return bean; } private static EntityManager getEmOrFail() { Optional<EntityManager> em = getEm(); if (!em.isPresent()) { throw JpaEvents.JPA202_MISSING_THREAD_EM(); } return em.get(); } private static Optional<EntityManager> getEm() { EntityManager em = ThreadLocalManager.peek(EntityManager.class); if (em == null) { return Optional.absent(); } return Optional.of(em); } @Transient private Set<JpaRef> references = new HashSet<>(); @Transient private Set<JpaProperty> properties = new HashSet<>(); public JpaBean() { } JpaBean(Bean b) { this.pk = new JpaBeanPk(b.getId()); } JpaBean(JpaBeanPk pk) { this.pk = pk; } public JpaBeanPk getPk() { return pk; } public BeanId getId() { return BeanId.create(pk.id, pk.schemaName); } public Set<JpaRef> getReferences() { return references; } public void addReference(JpaRef ref) { references.add(ref); } public Set<JpaProperty> getProperties() { return properties; } public void addProperty(String name, List<String> values) { for (String value : values) { properties.add(new JpaProperty(getId(), name, value)); } } public void addProperty(JpaProperty prop) { properties.add(prop); } @Override public boolean equals(Object obj) { if (!(obj instanceof JpaBean)) { return false; } JpaBean o = (JpaBean) obj; return equal(pk, o.pk); } @Override public int hashCode() { return Objects.hashCode(pk); } @Override public String toString() { return toStringHelper(JpaBean.class).add("pk", pk).toString(); } }