001: /*
002: * Copyright 2004-2006 the original author or authors.
003: *
004: * Licensed under the Apache License, Version 2.0 (the "License");
005: * you may not use this file except in compliance with the License.
006: * You may obtain a copy of the License at
007: *
008: * http://www.apache.org/licenses/LICENSE-2.0
009: *
010: * Unless required by applicable law or agreed to in writing, software
011: * distributed under the License is distributed on an "AS IS" BASIS,
012: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013: * See the License for the specific language governing permissions and
014: * limitations under the License.
015: */
016:
017: package org.compass.gps.device.jpa.entities;
018:
019: import java.util.ArrayList;
020: import javax.persistence.Entity;
021: import javax.persistence.EntityManagerFactory;
022: import javax.persistence.Inheritance;
023:
024: import org.apache.commons.logging.Log;
025: import org.apache.commons.logging.LogFactory;
026: import org.compass.core.mapping.ResourceMapping;
027: import org.compass.core.mapping.osem.ClassMapping;
028: import org.compass.core.spi.InternalCompass;
029: import org.compass.core.util.ClassUtils;
030: import org.compass.core.util.StringUtils;
031: import org.compass.gps.device.jpa.JpaGpsDevice;
032: import org.compass.gps.device.jpa.JpaGpsDeviceException;
033: import org.compass.gps.spi.CompassGpsInterfaceDevice;
034:
035: /**
036: * The default {@link JpaEntitiesLocator} implementations. Should work with all different
037: * JPA implementations, with the only caveat that it is based on Annotations only. So, any
038: * applications that uses a combination of both annotations and xml definitions (or any other
039: * type), will probably loose some information during the index process (providing that the
040: * xml definitions are ones that collide with Compass definitions). Please check if a
041: * JPA actual implementation is provided with compass in such cases, and if not, writing
042: * one should be simple (and should probably use the actual JPA implementation APIs).
043: *
044: * @author kimchy
045: */
046: public class DefaultJpaEntitiesLocator implements JpaEntitiesLocator {
047:
048: protected Log log = LogFactory.getLog(getClass());
049:
050: public EntityInformation[] locate(
051: EntityManagerFactory entityManagerFactory,
052: JpaGpsDevice device) throws JpaGpsDeviceException {
053: CompassGpsInterfaceDevice gps = (CompassGpsInterfaceDevice) device
054: .getGps();
055: final ResourceMapping[] resourceMappings = ((InternalCompass) gps
056: .getIndexCompass()).getMapping().getRootMappings();
057:
058: ArrayList<EntityInformation> entitiesList = new ArrayList<EntityInformation>(
059: resourceMappings.length);
060: for (ResourceMapping resourceMapping : resourceMappings) {
061: if (!(resourceMapping instanceof ClassMapping)) {
062: continue;
063: }
064: ClassMapping classMapping = (ClassMapping) resourceMapping;
065: if (!classMapping.isRoot()) {
066: continue;
067: }
068: EntityInformation entityInformation = createEntityInformation(
069: classMapping.getClazz(), resourceMapping);
070: if (entityInformation == null) {
071: continue;
072: }
073: if (shouldFilter(entityInformation, device)) {
074: continue;
075: }
076: entitiesList.add(entityInformation);
077: }
078: return entitiesList.toArray(new EntityInformation[entitiesList
079: .size()]);
080: }
081:
082: /**
083: * Creates the {@link EntityInformation} for a given class. If return <code>null</code>
084: * the class will be filtered out.
085: * <p/>
086: * Implementation filters out classes that do not have the {@link Entity} annotation (i.e.
087: * return <code>null</code> for such a case).
088: *
089: * @param clazz The class to create the {@link EntityInformation} for
090: * @param resourceMapping The Compass resource mapping (used for sub indexes extraction)
091: * @return The entity information, or <code>null</code> to filter it out
092: * @throws JpaGpsDeviceException
093: */
094: protected EntityInformation createEntityInformation(Class<?> clazz,
095: ResourceMapping resourceMapping)
096: throws JpaGpsDeviceException {
097: Entity entity = clazz.getAnnotation(Entity.class);
098: if (entity == null) {
099: return null;
100: }
101: String name;
102: if (StringUtils.hasLength(entity.name())) {
103: name = entity.name();
104: } else {
105: name = ClassUtils.getShortName(clazz);
106: }
107: return new EntityInformation(clazz, name, resourceMapping
108: .getSubIndexHash().getSubIndexes());
109: }
110:
111: /**
112: * Return <code>true</code> if the entity should be filtered out from the index operation.
113: * <p/>
114: * Implementation filters out classes that one of the super classes has the {@link Inheritance}
115: * annotation and the super class has compass mappings.
116: *
117: * @param entityInformation The entity information to check if it should be filtered
118: * @param device The Jpa gps device
119: * @return <code>true</code> if the entity should be filtered from the index process
120: */
121: protected boolean shouldFilter(EntityInformation entityInformation,
122: JpaGpsDevice device) {
123: Class<?> clazz = entityInformation.getEntityClass()
124: .getSuperclass();
125: while (true) {
126: if (clazz == null || clazz.equals(Object.class)) {
127: break;
128: }
129: if (clazz.isAnnotationPresent(Inheritance.class)
130: && ((CompassGpsInterfaceDevice) device.getGps())
131: .hasMappingForEntityForIndex(clazz)) {
132: if (log.isDebugEnabled()) {
133: log
134: .debug("Entity ["
135: + entityInformation.getName()
136: + "] is inherited and super class ["
137: + clazz
138: + "] has compass mapping, filtering it out");
139: }
140: return true;
141: }
142: clazz = clazz.getSuperclass();
143: }
144: return false;
145: }
146: }
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