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* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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
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package org.apache.cayenne.map;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import org.apache.commons.collections.Transformer;
import org.apache.cayenne.CayenneRuntimeException;
import org.apache.cayenne.ObjectId;
import org.apache.cayenne.exp.Expression;
import org.apache.cayenne.exp.ExpressionException;
import org.apache.cayenne.exp.ExpressionFactory;
import org.apache.cayenne.map.event.AttributeEvent;
import org.apache.cayenne.map.event.DbAttributeListener;
import org.apache.cayenne.map.event.DbEntityListener;
import org.apache.cayenne.map.event.DbRelationshipListener;
import org.apache.cayenne.map.event.EntityEvent;
import org.apache.cayenne.map.event.MapEvent;
import org.apache.cayenne.map.event.RelationshipEvent;
import org.apache.cayenne.util.CayenneMapEntry;
import org.apache.cayenne.util.Util;
import org.apache.cayenne.util.XMLEncoder;
/**
* A DbEntity is a mapping descriptor that defines a structure of a database table.
*
* @author Misha Shengaout
* @author Andrus Adamchik
*/
public class DbEntity extends Entity implements DbEntityListener, DbAttributeListener,
DbRelationshipListener {
protected String catalog;
protected String schema;
protected List primaryKey;
/**
* @since 1.2
*/
protected Collection generatedAttributes;
protected DbKeyGenerator primaryKeyGenerator;
/**
* Creates an unnamed DbEntity.
*/
public DbEntity() {
super();
this.primaryKey = new ArrayList(2);
this.generatedAttributes = new ArrayList(2);
}
/**
* Creates a named DbEntity.
*/
public DbEntity(String name) {
this();
this.setName(name);
}
/**
* Prints itself as XML to the provided XMLEncoder.
*
* @since 1.1
*/
public void encodeAsXML(XMLEncoder encoder) {
encoder.print("<db-entity name=\"");
encoder.print(Util.encodeXmlAttribute(getName()));
encoder.print('\"');
if (getSchema() != null && getSchema().trim().length() > 0) {
encoder.print(" schema=\"");
encoder.print(Util.encodeXmlAttribute(getSchema().trim()));
encoder.print('\"');
}
if (getCatalog() != null && getCatalog().trim().length() > 0) {
encoder.print(" catalog=\"");
encoder.print(Util.encodeXmlAttribute(getCatalog().trim()));
encoder.print('\"');
}
encoder.println('>');
encoder.indent(1);
encoder.print(getAttributeMap());
if (getPrimaryKeyGenerator() != null) {
getPrimaryKeyGenerator().encodeAsXML(encoder);
}
encoder.indent(-1);
encoder.println("</db-entity>");
}
/**
* Returns table name including schema, if present.
*/
public String getFullyQualifiedName() {
return (schema != null) ? schema + '.' + getName() : getName();
}
/**
* Returns database schema of this table.
*
* @return table's schema, null if not set.
*/
public String getSchema() {
return schema;
}
/**
* Sets the database schema name of the table described by this DbEntity.
*/
public void setSchema(String schema) {
this.schema = schema;
}
/**
* Returns the catalog name of the table described by this DbEntity.
*/
public String getCatalog() {
return catalog;
}
/**
* Sets the catalog name of the table described by this DbEntity.
*/
public void setCatalog(String catalog) {
this.catalog = catalog;
}
/**
* Returns an unmodifiable list of DbAttributes representing the primary key of the
* table described by this DbEntity.
*/
// TODO: (Andrus 09/06/2005) Change to Collection ... no reason to keep as list other
// than backwards compatibility
public List getPrimaryKey() {
return Collections.unmodifiableList(primaryKey);
}
/**
* Returns an unmodifiable collection of DbAttributes that are generated by the
* database.
*
* @since 1.2
*/
public Collection getGeneratedAttributes() {
return Collections.unmodifiableCollection(generatedAttributes);
}
/**
* Overrides super to fire an AttributeEvent.
*/
public void addAttribute(Attribute attr) {
super.addAttribute(attr);
this.dbAttributeAdded(new AttributeEvent(this, attr, this, MapEvent.ADD));
}
/**
* Removes attribute from the entity, removes any relationship joins containing this
* attribute.
*
* @see org.apache.cayenne.map.Entity#removeAttribute(String)
*/
public void removeAttribute(String attrName) {
Attribute attr = getAttribute(attrName);
if (attr == null) {
return;
}
DataMap map = getDataMap();
if (map != null) {
Iterator ents = map.getDbEntities().iterator();
while (ents.hasNext()) {
DbEntity ent = (DbEntity) ents.next();
Iterator it = ent.getRelationships().iterator();
while (it.hasNext()) {
DbRelationship rel = (DbRelationship) it.next();
Iterator joins = rel.getJoins().iterator();
while (joins.hasNext()) {
DbJoin join = (DbJoin) joins.next();
if (join.getSource() == attr || join.getTarget() == attr) {
joins.remove();
}
}
}
}
}
super.removeAttribute(attrName);
this.dbAttributeRemoved(new AttributeEvent(this, attr, this, MapEvent.REMOVE));
}
public void clearAttributes() {
super.clearAttributes();
// post dummy event for no specific attribute
this.dbAttributeRemoved(new AttributeEvent(this, null, this, MapEvent.REMOVE));
}
public Iterator resolvePathComponents(Expression pathExp) throws ExpressionException {
if (pathExp.getType() != Expression.DB_PATH) {
throw new ExpressionException("Invalid expression type: '"
+ pathExp.expName()
+ "', DB_PATH is expected.");
}
return new PathIterator((String) pathExp.getOperand(0));
}
public void setPrimaryKeyGenerator(DbKeyGenerator primaryKeyGenerator) {
this.primaryKeyGenerator = primaryKeyGenerator;
if (primaryKeyGenerator != null) {
primaryKeyGenerator.setDbEntity(this);
}
}
public DbKeyGenerator getPrimaryKeyGenerator() {
return primaryKeyGenerator;
}
/**
* DbEntity property changed. May be name, attribute or relationship added or removed,
* etc. Attribute and relationship property changes are handled in respective
* listeners.
*
* @since 1.2
*/
public void dbEntityChanged(EntityEvent e) {
if ((e == null) || (e.getEntity() != this)) {
// not our concern
return;
}
// handle entity name changes
if (e.getId() == EntityEvent.CHANGE && e.isNameChange()) {
String newName = e.getNewName();
DataMap map = getDataMap();
if (map != null) {
// handle all of the relationship target names that need to be changed
Iterator ents = map.getDbEntities().iterator();
while (ents.hasNext()) {
DbEntity dbe = (DbEntity) ents.next();
Iterator rit = dbe.getRelationships().iterator();
while (rit.hasNext()) {
DbRelationship rel = (DbRelationship) rit.next();
if (rel.getTargetEntity() == this) {
rel.setTargetEntityName(newName);
}
}
}
// get all of the related object entities
ents = map.getMappedEntities(this).iterator();
while (ents.hasNext()) {
ObjEntity oe = (ObjEntity) ents.next();
if (oe.getDbEntity() == this) {
oe.setDbEntityName(newName);
}
}
}
}
}
/** New entity has been created/added. */
public void dbEntityAdded(EntityEvent e) {
// does nothing currently
}
/** Entity has been removed. */
public void dbEntityRemoved(EntityEvent e) {
// does nothing currently
}
public void dbAttributeAdded(AttributeEvent e) {
this.handleAttributeUpdate(e);
}
public void dbAttributeChanged(AttributeEvent e) {
this.handleAttributeUpdate(e);
}
public void dbAttributeRemoved(AttributeEvent e) {
this.handleAttributeUpdate(e);
}
private void handleAttributeUpdate(AttributeEvent e) {
if ((e == null) || (e.getEntity() != this)) {
// not our concern
return;
}
// catch clearing (event with null ('any') DbAttribute)
Attribute attr = e.getAttribute();
if ((attr == null) && (this.attributes.isEmpty())) {
this.primaryKey.clear();
this.generatedAttributes.clear();
return;
}
// make sure we handle a DbAttribute
if (!(attr instanceof DbAttribute)) {
return;
}
DbAttribute dbAttr = (DbAttribute) attr;
// handle attribute name changes
if (e.getId() == AttributeEvent.CHANGE && e.isNameChange()) {
String oldName = e.getOldName();
String newName = e.getNewName();
DataMap map = getDataMap();
if (map != null) {
Iterator ents = map.getDbEntities().iterator();
while (ents.hasNext()) {
DbEntity ent = (DbEntity) ents.next();
// handle all of the dependent object entity attribute changes
Iterator it = map.getMappedEntities(ent).iterator();
while (it.hasNext()) {
ObjEntity oe = (ObjEntity) it.next();
Iterator ait = oe.getAttributes().iterator();
while (ait.hasNext()) {
ObjAttribute oa = (ObjAttribute) ait.next();
if (oa.getDbAttribute() == dbAttr) {
oa.setDbAttributeName(newName);
}
}
}
// handle all of the relationships / joins that use the changed
// attribute
it = ent.getRelationships().iterator();
while (it.hasNext()) {
DbRelationship rel = (DbRelationship) it.next();
Iterator joins = rel.getJoins().iterator();
while (joins.hasNext()) {
DbJoin join = (DbJoin) joins.next();
if (join.getSource() == dbAttr) {
join.setSourceName(newName);
}
if (join.getTarget() == dbAttr) {
join.setTargetName(newName);
}
}
}
}
}
// clear the attribute out of the collection
attributes.remove(oldName);
// add the attribute back in with the new name
super.addAttribute(dbAttr);
}
// handle PK refresh
if (primaryKey.contains(dbAttr) || dbAttr.isPrimaryKey()) {
switch (e.getId()) {
case MapEvent.ADD:
this.primaryKey.add(attr);
break;
case MapEvent.REMOVE:
this.primaryKey.remove(attr);
break;
default:
// generic update
this.primaryKey.clear();
Iterator it = this.getAttributes().iterator();
while (it.hasNext()) {
DbAttribute dba = (DbAttribute) it.next();
if (dba.isPrimaryKey()) {
this.primaryKey.add(dba);
}
}
}
}
// handle generated key refresh
if (generatedAttributes.contains(dbAttr) || dbAttr.isGenerated()) {
switch (e.getId()) {
case MapEvent.ADD:
this.generatedAttributes.add(attr);
break;
case MapEvent.REMOVE:
this.generatedAttributes.remove(attr);
break;
default:
// generic update
this.generatedAttributes.clear();
Iterator it = this.getAttributes().iterator();
while (it.hasNext()) {
DbAttribute dba = (DbAttribute) it.next();
if (dba.isGenerated()) {
this.generatedAttributes.add(dba);
}
}
}
}
}
/**
* Relationship property changed.
*/
public void dbRelationshipChanged(RelationshipEvent e) {
if ((e == null) || (e.getEntity() != this)) {
// not our concern
return;
}
Relationship rel = e.getRelationship();
// make sure we handle a DbRelationship
if (!(rel instanceof DbRelationship)) {
return;
}
DbRelationship dbRel = (DbRelationship) rel;
// handle relationship name changes
if (e.getId() == RelationshipEvent.CHANGE && e.isNameChange()) {
String oldName = e.getOldName();
String newName = e.getNewName();
DataMap map = getDataMap();
if (map != null) {
// finds all object entities with a db relationship path to the renamed
// relationship
Iterator ents = map.getObjEntities().iterator();
while (ents.hasNext()) {
ObjEntity oe = (ObjEntity) ents.next();
Iterator rit = oe.getRelationships().iterator();
while (rit.hasNext()) {
ObjRelationship or = (ObjRelationship) rit.next();
// rename the db relationship path with the new name
if (Util.nullSafeEquals(or.getDbRelationshipPath(), oldName)) {
or.setDbRelationshipPath(newName);
}
}
}
}
// clear the relationship out of the collection
relationships.remove(oldName);
// add the relationship back in with the new name
super.addRelationship(dbRel);
}
}
/** Relationship has been created/added. */
public void dbRelationshipAdded(RelationshipEvent e) {
// does nothing currently
}
/** Relationship has been removed. */
public void dbRelationshipRemoved(RelationshipEvent e) {
// does nothing currently
}
/**
* Returns true if there is full replacement id is attached to an ObjectId. "Full"
* means that all PK columns are present and only PK columns are present.
*
* @since 1.2
*/
public boolean isFullReplacementIdAttached(ObjectId id) {
if (!id.isReplacementIdAttached()) {
return false;
}
Map replacement = id.getReplacementIdMap();
Collection pk = getPrimaryKey();
if (pk.size() != replacement.size()) {
return false;
}
Iterator it = pk.iterator();
while (it.hasNext()) {
DbAttribute attribute = (DbAttribute) it.next();
if (!replacement.containsKey(attribute.getName())) {
return false;
}
}
return true;
}
/**
* Transforms Expression rooted in this entity to an analogous expression rooted in
* related entity.
*
* @since 1.1
*/
public Expression translateToRelatedEntity(
Expression expression,
String relationshipPath) {
if (expression == null) {
return null;
}
if (relationshipPath == null) {
return expression;
}
return expression.transform(new RelationshipPathConverter(relationshipPath));
}
final class RelationshipPathConverter implements Transformer {
String relationshipPath;
RelationshipPathConverter(String relationshipPath) {
this.relationshipPath = relationshipPath;
}
public Object transform(Object input) {
if (!(input instanceof Expression)) {
return input;
}
Expression expression = (Expression) input;
if (expression.getType() != Expression.DB_PATH) {
return input;
}
String path = (String) expression.getOperand(0);
String converted = translatePath(path);
Expression transformed = ExpressionFactory
.expressionOfType(Expression.DB_PATH);
transformed.setOperand(0, converted);
return transformed;
}
String translatePath(String path) {
// algorithm to determine the translated path:
// 1. If relationship path equals to input, travel one step back, and then one
// step forward.
// 2. If input completely includes relationship path, use input's remaining
// tail.
// 3. If relationship path and input have none or some leading components in
// common,
// (a) strip common leading part;
// (b) reverse the remaining relationship part;
// (c) append remaining input to the reversed remaining relationship.
// case (1)
if (path.equals(relationshipPath)) {
LinkedList finalPath = new LinkedList();
Iterator it = resolvePathComponents(path);
// just do one step back and one step forward to create correct joins...
// find last rel...
DbRelationship lastDBR = null;
while (it.hasNext()) {
// relationship path components must be DbRelationships
lastDBR = (DbRelationship) it.next();
}
if (lastDBR != null) {
prependReversedPath(finalPath, lastDBR);
appendPath(finalPath, lastDBR);
}
return convertToPath(finalPath);
}
// case (2)
String relationshipPathWithDot = relationshipPath + Entity.PATH_SEPARATOR;
if (path.startsWith(relationshipPathWithDot)) {
return path.substring(relationshipPathWithDot.length());
}
// case (3)
Iterator pathIt = resolvePathComponents(path);
Iterator relationshipIt = resolvePathComponents(relationshipPath);
// for inserts from the both ends use LinkedList
LinkedList finalPath = new LinkedList();
while (relationshipIt.hasNext() && pathIt.hasNext()) {
// relationship path components must be DbRelationships
DbRelationship nextDBR = (DbRelationship) relationshipIt.next();
// expression components may be attributes or relationships
CayenneMapEntry next = (CayenneMapEntry) pathIt.next();
if (nextDBR != next) {
// found split point
// consume the last iteration components,
// then break out to finish the iterators independenly
prependReversedPath(finalPath, nextDBR);
appendPath(finalPath, next);
break;
}
break;
}
// append remainder of the relationship, reversing it
while (relationshipIt.hasNext()) {
DbRelationship nextDBR = (DbRelationship) relationshipIt.next();
prependReversedPath(finalPath, nextDBR);
}
while (pathIt.hasNext()) {
// components may be attributes or relationships
CayenneMapEntry next = (CayenneMapEntry) pathIt.next();
appendPath(finalPath, next);
}
return convertToPath(finalPath);
}
private String convertToPath(List path) {
StringBuffer converted = new StringBuffer();
int len = path.size();
for (int i = 0; i < len; i++) {
if (i > 0) {
converted.append(Entity.PATH_SEPARATOR);
}
converted.append(path.get(i));
}
return converted.toString();
}
private void prependReversedPath(LinkedList finalPath, DbRelationship relationship) {
DbRelationship revNextDBR = relationship.getReverseRelationship();
if (revNextDBR == null) {
throw new CayenneRuntimeException(
"Unable to find reverse DbRelationship for "
+ relationship.getSourceEntity().getName()
+ Entity.PATH_SEPARATOR
+ relationship.getName()
+ ".");
}
finalPath.addFirst(revNextDBR.getName());
}
private void appendPath(LinkedList finalPath, CayenneMapEntry pathComponent) {
finalPath.addLast(pathComponent.getName());
}
}
}