Hibernate example source code file (JoinWalker.java)
The Hibernate JoinWalker.java source code/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2010, Red Hat Inc. or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Inc.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.hibernate.loader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import org.hibernate.FetchMode;
import org.hibernate.LockMode;
import org.hibernate.LockOptions;
import org.hibernate.MappingException;
import org.hibernate.dialect.Dialect;
import org.hibernate.engine.spi.CascadeStyle;
import org.hibernate.engine.internal.JoinHelper;
import org.hibernate.engine.spi.LoadQueryInfluencers;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.internal.util.StringHelper;
import org.hibernate.internal.util.collections.ArrayHelper;
import org.hibernate.mapping.Join;
import org.hibernate.persister.collection.CollectionPersister;
import org.hibernate.persister.collection.QueryableCollection;
import org.hibernate.persister.entity.EntityPersister;
import org.hibernate.persister.entity.Joinable;
import org.hibernate.persister.entity.Loadable;
import org.hibernate.persister.entity.OuterJoinLoadable;
import org.hibernate.sql.ConditionFragment;
import org.hibernate.sql.DisjunctionFragment;
import org.hibernate.sql.InFragment;
import org.hibernate.sql.JoinFragment;
import org.hibernate.sql.JoinType;
import org.hibernate.type.AssociationType;
import org.hibernate.type.CompositeType;
import org.hibernate.type.EntityType;
import org.hibernate.type.ForeignKeyDirection;
import org.hibernate.type.Type;
/**
* Walks the metamodel, searching for joins, and collecting
* together information needed by <tt>OuterJoinLoader.
*
* @see OuterJoinLoader
* @author Gavin King, Jon Lipsky
*/
public class JoinWalker {
private final SessionFactoryImplementor factory;
protected final List associations = new ArrayList();
private final Set visitedAssociationKeys = new HashSet();
private final LoadQueryInfluencers loadQueryInfluencers;
protected String[] suffixes;
protected String[] collectionSuffixes;
protected Loadable[] persisters;
protected int[] owners;
protected EntityType[] ownerAssociationTypes;
protected CollectionPersister[] collectionPersisters;
protected int[] collectionOwners;
protected String[] aliases;
protected LockOptions lockOptions;
protected LockMode[] lockModeArray;
protected String sql;
protected JoinWalker(
SessionFactoryImplementor factory,
LoadQueryInfluencers loadQueryInfluencers) {
this.factory = factory;
this.loadQueryInfluencers = loadQueryInfluencers;
}
public String[] getCollectionSuffixes() {
return collectionSuffixes;
}
public void setCollectionSuffixes(String[] collectionSuffixes) {
this.collectionSuffixes = collectionSuffixes;
}
public LockOptions getLockModeOptions() {
return lockOptions;
}
public LockMode[] getLockModeArray() {
return lockModeArray;
}
public String[] getSuffixes() {
return suffixes;
}
public void setSuffixes(String[] suffixes) {
this.suffixes = suffixes;
}
public String[] getAliases() {
return aliases;
}
public void setAliases(String[] aliases) {
this.aliases = aliases;
}
public int[] getCollectionOwners() {
return collectionOwners;
}
public void setCollectionOwners(int[] collectionOwners) {
this.collectionOwners = collectionOwners;
}
public CollectionPersister[] getCollectionPersisters() {
return collectionPersisters;
}
public void setCollectionPersisters(CollectionPersister[] collectionPersisters) {
this.collectionPersisters = collectionPersisters;
}
public EntityType[] getOwnerAssociationTypes() {
return ownerAssociationTypes;
}
public void setOwnerAssociationTypes(EntityType[] ownerAssociationType) {
this.ownerAssociationTypes = ownerAssociationType;
}
public int[] getOwners() {
return owners;
}
public void setOwners(int[] owners) {
this.owners = owners;
}
public Loadable[] getPersisters() {
return persisters;
}
public void setPersisters(Loadable[] persisters) {
this.persisters = persisters;
}
public String getSQLString() {
return sql;
}
public void setSql(String sql) {
this.sql = sql;
}
protected SessionFactoryImplementor getFactory() {
return factory;
}
protected Dialect getDialect() {
return factory.getDialect();
}
public LoadQueryInfluencers getLoadQueryInfluencers() {
return loadQueryInfluencers;
}
/**
* Add on association (one-to-one, many-to-one, or a collection) to a list
* of associations to be fetched by outerjoin (if necessary)
*/
private void addAssociationToJoinTreeIfNecessary(
final AssociationType type,
final String[] aliasedLhsColumns,
final String alias,
final PropertyPath path,
int currentDepth,
final JoinType joinType) throws MappingException {
if ( joinType != JoinType.NONE ) {
addAssociationToJoinTree(
type,
aliasedLhsColumns,
alias,
path,
currentDepth,
joinType
);
}
}
protected boolean hasRestriction(PropertyPath path) {
return false;
}
protected String getWithClause(PropertyPath path) {
return "";
}
/**
* Add on association (one-to-one, many-to-one, or a collection) to a list
* of associations to be fetched by outerjoin
*/
private void addAssociationToJoinTree(
final AssociationType type,
final String[] aliasedLhsColumns,
final String alias,
final PropertyPath path,
final int currentDepth,
final JoinType joinType) throws MappingException {
Joinable joinable = type.getAssociatedJoinable( getFactory() );
// important to generate alias based on size of association collection
// *before* adding this join to that collection
String subalias = generateTableAlias( associations.size() + 1, path, joinable );
// NOTE : it should be fine to continue to pass only filters below
// (instead of LoadQueryInfluencers) since "from that point on" we
// only need to worry about restrictions (and not say adding more
// joins)
OuterJoinableAssociation assoc = new OuterJoinableAssociation(
path,
type,
alias,
aliasedLhsColumns,
subalias,
joinType,
getWithClause(path),
hasRestriction( path ),
getFactory(),
loadQueryInfluencers.getEnabledFilters()
);
assoc.validateJoin( path.getFullPath() );
associations.add( assoc );
int nextDepth = currentDepth + 1;
// path = "";
if ( !joinable.isCollection() ) {
if (joinable instanceof OuterJoinLoadable) {
walkEntityTree(
(OuterJoinLoadable) joinable,
subalias,
path,
nextDepth
);
}
}
else {
if (joinable instanceof QueryableCollection) {
walkCollectionTree(
(QueryableCollection) joinable,
subalias,
path,
nextDepth
);
}
}
}
/**
* Walk the association tree for an entity, adding associations which should
* be join fetched to the {@link #associations} inst var. This form is the
* entry point into the walking for a given entity, starting the recursive
* calls into {@link #walkEntityTree(org.hibernate.persister.entity.OuterJoinLoadable, String, PropertyPath ,int)}.
*
* @param persister The persister representing the entity to be walked.
* @param alias The (root) alias to use for this entity/persister.
* @throws org.hibernate.MappingException ???
*/
protected final void walkEntityTree(
OuterJoinLoadable persister,
String alias) throws MappingException {
walkEntityTree( persister, alias, new PropertyPath(), 0 );
}
/**
* For a collection role, return a list of associations to be fetched by outerjoin
*/
protected final void walkCollectionTree(QueryableCollection persister, String alias) throws MappingException {
walkCollectionTree( persister, alias, new PropertyPath(), 0 );
//TODO: when this is the entry point, we should use an INNER_JOIN for fetching the many-to-many elements!
}
/**
* For a collection role, return a list of associations to be fetched by outerjoin
*/
private void walkCollectionTree(
final QueryableCollection persister,
final String alias,
final PropertyPath path,
final int currentDepth) throws MappingException {
if ( persister.isOneToMany() ) {
walkEntityTree(
(OuterJoinLoadable) persister.getElementPersister(),
alias,
path,
currentDepth
);
}
else {
Type type = persister.getElementType();
if ( type.isAssociationType() ) {
// a many-to-many;
// decrement currentDepth here to allow join across the association table
// without exceeding MAX_FETCH_DEPTH (i.e. the "currentDepth - 1" bit)
AssociationType associationType = (AssociationType) type;
String[] aliasedLhsColumns = persister.getElementColumnNames(alias);
String[] lhsColumns = persister.getElementColumnNames();
// if the current depth is 0, the root thing being loaded is the
// many-to-many collection itself. Here, it is alright to use
// an inner join...
boolean useInnerJoin = currentDepth == 0;
final JoinType joinType = getJoinType(
associationType,
persister.getFetchMode(),
path,
persister.getTableName(),
lhsColumns,
!useInnerJoin,
currentDepth - 1,
null //operations which cascade as far as the collection also cascade to collection elements
);
addAssociationToJoinTreeIfNecessary(
associationType,
aliasedLhsColumns,
alias,
path,
currentDepth - 1,
joinType
);
}
else if ( type.isComponentType() ) {
walkCompositeElementTree(
(CompositeType) type,
persister.getElementColumnNames(),
persister,
alias,
path,
currentDepth
);
}
}
}
/**
* Process a particular association owned by the entity
*
* @param associationType The type representing the association to be
* processed.
* @param persister The owner of the association to be processed.
* @param propertyNumber The property number for the association
* (relative to the persister).
* @param alias The entity alias
* @param path The path to the association
* @param nullable is the association nullable (which I think is supposed
* to indicate inner/outer join semantics).
* @param currentDepth The current join depth
* @throws org.hibernate.MappingException ???
*/
private void walkEntityAssociationTree(
final AssociationType associationType,
final OuterJoinLoadable persister,
final int propertyNumber,
final String alias,
final PropertyPath path,
final boolean nullable,
final int currentDepth) throws MappingException {
String[] aliasedLhsColumns = JoinHelper.getAliasedLHSColumnNames(
associationType, alias, propertyNumber, persister, getFactory()
);
String[] lhsColumns = JoinHelper.getLHSColumnNames(
associationType, propertyNumber, persister, getFactory()
);
String lhsTable = JoinHelper.getLHSTableName(associationType, propertyNumber, persister);
PropertyPath subPath = path.append( persister.getSubclassPropertyName(propertyNumber) );
JoinType joinType = getJoinType(
persister,
subPath,
propertyNumber,
associationType,
persister.getFetchMode( propertyNumber ),
persister.getCascadeStyle( propertyNumber ),
lhsTable,
lhsColumns,
nullable,
currentDepth
);
addAssociationToJoinTreeIfNecessary(
associationType,
aliasedLhsColumns,
alias,
subPath,
currentDepth,
joinType
);
}
/**
* Determine the appropriate type of join (if any) to use to fetch the
* given association.
*
* @param persister The owner of the association.
* @param path The path to the association
* @param propertyNumber The property number representing the association.
* @param associationType The association type.
* @param metadataFetchMode The metadata-defined fetch mode.
* @param metadataCascadeStyle The metadata-defined cascade style.
* @param lhsTable The owner table
* @param lhsColumns The owner join columns
* @param nullable Is the association nullable.
* @param currentDepth Current join depth
* @return type of join to use ({@link org.hibernate.sql.JoinType#INNER_JOIN},
* {@link org.hibernate.sql.JoinType#LEFT_OUTER_JOIN}, or -1 to indicate no joining.
* @throws MappingException ??
*/
protected JoinType getJoinType(
OuterJoinLoadable persister,
final PropertyPath path,
int propertyNumber,
AssociationType associationType,
FetchMode metadataFetchMode,
CascadeStyle metadataCascadeStyle,
String lhsTable,
String[] lhsColumns,
final boolean nullable,
final int currentDepth) throws MappingException {
return getJoinType(
associationType,
metadataFetchMode,
path,
lhsTable,
lhsColumns,
nullable,
currentDepth,
metadataCascadeStyle
);
}
/**
* Determine the appropriate associationType of join (if any) to use to fetch the
* given association.
*
* @param associationType The association associationType.
* @param config The metadata-defined fetch mode.
* @param path The path to the association
* @param lhsTable The owner table
* @param lhsColumns The owner join columns
* @param nullable Is the association nullable.
* @param currentDepth Current join depth
* @param cascadeStyle The metadata-defined cascade style.
* @return type of join to use ({@link org.hibernate.sql.JoinType#INNER_JOIN},
* {@link org.hibernate.sql.JoinType#LEFT_OUTER_JOIN}, or -1 to indicate no joining.
* @throws MappingException ??
*/
protected JoinType getJoinType(
AssociationType associationType,
FetchMode config,
PropertyPath path,
String lhsTable,
String[] lhsColumns,
boolean nullable,
int currentDepth,
CascadeStyle cascadeStyle) throws MappingException {
if ( !isJoinedFetchEnabled( associationType, config, cascadeStyle ) ) {
return JoinType.NONE;
}
if ( isTooDeep(currentDepth) || ( associationType.isCollectionType() && isTooManyCollections() ) ) {
return JoinType.NONE;
}
if ( isDuplicateAssociation( lhsTable, lhsColumns, associationType ) ) {
return JoinType.NONE;
}
return getJoinType( nullable, currentDepth );
}
/**
* Walk the association tree for an entity, adding associations which should
* be join fetched to the {@link #associations} inst var. This form is the
* entry point into the walking for a given entity, starting the recursive
* calls into {@link #walkEntityTree(org.hibernate.persister.entity.OuterJoinLoadable, String, PropertyPath ,int)}.
*
* @param persister The persister representing the entity to be walked.
* @param alias The (root) alias to use for this entity/persister.
* @param path The property path to the entity being walked
* @param currentDepth The current join depth
* @throws org.hibernate.MappingException ???
*/
private void walkEntityTree(
final OuterJoinLoadable persister,
final String alias,
final PropertyPath path,
final int currentDepth) throws MappingException {
int n = persister.countSubclassProperties();
for ( int i = 0; i < n; i++ ) {
Type type = persister.getSubclassPropertyType(i);
if ( type.isAssociationType() ) {
walkEntityAssociationTree(
( AssociationType ) type,
persister,
i,
alias,
path,
persister.isSubclassPropertyNullable(i),
currentDepth
);
}
else if ( type.isComponentType() ) {
walkComponentTree(
( CompositeType ) type,
i,
0,
persister,
alias,
path.append( persister.getSubclassPropertyName(i) ),
currentDepth
);
}
}
}
/**
* For a component, add to a list of associations to be fetched by outerjoin
*
*
* @param componentType The component type to be walked.
* @param propertyNumber The property number for the component property (relative to
* persister).
* @param begin todo unknowm
* @param persister The owner of the component property
* @param alias The root alias
* @param path The property access path
* @param currentDepth The current join depth
* @throws org.hibernate.MappingException ???
*/
private void walkComponentTree(
final CompositeType componentType,
final int propertyNumber,
int begin,
final OuterJoinLoadable persister,
final String alias,
final PropertyPath path,
final int currentDepth) throws MappingException {
Type[] types = componentType.getSubtypes();
String[] propertyNames = componentType.getPropertyNames();
for ( int i = 0; i < types.length; i++ ) {
if ( types[i].isAssociationType() ) {
AssociationType associationType = (AssociationType) types[i];
String[] aliasedLhsColumns = JoinHelper.getAliasedLHSColumnNames(
associationType, alias, propertyNumber, begin, persister, getFactory()
);
String[] lhsColumns = JoinHelper.getLHSColumnNames(
associationType, propertyNumber, begin, persister, getFactory()
);
String lhsTable = JoinHelper.getLHSTableName(associationType, propertyNumber, persister);
final PropertyPath subPath = path.append( propertyNames[i] );
final boolean[] propertyNullability = componentType.getPropertyNullability();
final JoinType joinType = getJoinType(
persister,
subPath,
propertyNumber,
associationType,
componentType.getFetchMode(i),
componentType.getCascadeStyle(i),
lhsTable,
lhsColumns,
propertyNullability==null || propertyNullability[i],
currentDepth
);
addAssociationToJoinTreeIfNecessary(
associationType,
aliasedLhsColumns,
alias,
subPath,
currentDepth,
joinType
);
}
else if ( types[i].isComponentType() ) {
final PropertyPath subPath = path.append( propertyNames[i] );
walkComponentTree(
( CompositeType ) types[i],
propertyNumber,
begin,
persister,
alias,
subPath,
currentDepth
);
}
begin += types[i].getColumnSpan( getFactory() );
}
}
/**
* For a composite element, add to a list of associations to be fetched by outerjoin
*/
private void walkCompositeElementTree(
final CompositeType compositeType,
final String[] cols,
final QueryableCollection persister,
final String alias,
final PropertyPath path,
final int currentDepth) throws MappingException {
Type[] types = compositeType.getSubtypes();
String[] propertyNames = compositeType.getPropertyNames();
int begin = 0;
for ( int i=0; i <types.length; i++ ) {
int length = types[i].getColumnSpan( getFactory() );
String[] lhsColumns = ArrayHelper.slice(cols, begin, length);
if ( types[i].isAssociationType() ) {
AssociationType associationType = (AssociationType) types[i];
// simple, because we can't have a one-to-one or a collection
// (or even a property-ref) in a composite-element:
String[] aliasedLhsColumns = StringHelper.qualify(alias, lhsColumns);
final PropertyPath subPath = path.append( propertyNames[i] );
final boolean[] propertyNullability = compositeType.getPropertyNullability();
final JoinType joinType = getJoinType(
associationType,
compositeType.getFetchMode(i),
subPath,
persister.getTableName(),
lhsColumns,
propertyNullability==null || propertyNullability[i],
currentDepth,
compositeType.getCascadeStyle(i)
);
addAssociationToJoinTreeIfNecessary(
associationType,
aliasedLhsColumns,
alias,
subPath,
currentDepth,
joinType
);
}
else if ( types[i].isComponentType() ) {
final PropertyPath subPath = path.append( propertyNames[i] );
walkCompositeElementTree(
(CompositeType) types[i],
lhsColumns,
persister,
alias,
subPath,
currentDepth
);
}
begin+=length;
}
}
/**
* Use an inner join if it is a non-null association and this
* is the "first" join in a series
*/
protected JoinType getJoinType(boolean nullable, int currentDepth) {
//TODO: this is too conservative; if all preceding joins were
// also inner joins, we could use an inner join here
//
// IMPL NOTE : currentDepth might be less-than zero if this is the
// root of a many-to-many collection initializer
return !nullable && currentDepth <= 0
? JoinType.INNER_JOIN
: JoinType.LEFT_OUTER_JOIN;
}
protected boolean isTooDeep(int currentDepth) {
Integer maxFetchDepth = getFactory().getSettings().getMaximumFetchDepth();
return maxFetchDepth!=null && currentDepth >= maxFetchDepth.intValue();
}
protected boolean isTooManyCollections() {
return false;
}
/**
* Does the mapping, and Hibernate default semantics, specify that
* this association should be fetched by outer joining
*/
protected boolean isJoinedFetchEnabledInMapping(FetchMode config, AssociationType type)
throws MappingException {
if ( !type.isEntityType() && !type.isCollectionType() ) {
return false;
}
else {
if (config==FetchMode.JOIN) return true;
if (config==FetchMode.SELECT) return false;
if ( type.isEntityType() ) {
//TODO: look at the owning property and check that it
// isn't lazy (by instrumentation)
EntityType entityType =(EntityType) type;
EntityPersister persister = getFactory().getEntityPersister( entityType.getAssociatedEntityName() );
return !persister.hasProxy();
}
else {
return false;
}
}
}
/**
* Override on subclasses to enable or suppress joining
* of certain association types
*/
protected boolean isJoinedFetchEnabled(AssociationType type, FetchMode config, CascadeStyle cascadeStyle) {
return type.isEntityType() && isJoinedFetchEnabledInMapping(config, type) ;
}
protected String generateTableAlias(final int n, final PropertyPath path, final Joinable joinable) {
return StringHelper.generateAlias( joinable.getName(), n );
}
protected String generateRootAlias(final String description) {
return StringHelper.generateAlias(description, 0);
}
/**
* Used to detect circularities in the joined graph, note that
* this method is side-effecty
*/
protected boolean isDuplicateAssociation(final String foreignKeyTable, final String[] foreignKeyColumns) {
AssociationKey associationKey = new AssociationKey(foreignKeyColumns, foreignKeyTable);
return !visitedAssociationKeys.add( associationKey );
}
/**
* Used to detect circularities in the joined graph, note that
* this method is side-effecty
*/
protected boolean isDuplicateAssociation(final String lhsTable, final String[] lhsColumnNames, final AssociationType type) {
final String foreignKeyTable;
final String[] foreignKeyColumns;
if ( type.getForeignKeyDirection()==ForeignKeyDirection.FOREIGN_KEY_FROM_PARENT ) {
foreignKeyTable = lhsTable;
foreignKeyColumns = lhsColumnNames;
}
else {
foreignKeyTable = type.getAssociatedJoinable( getFactory() ).getTableName();
foreignKeyColumns = JoinHelper.getRHSColumnNames( type, getFactory() );
}
return isDuplicateAssociation(foreignKeyTable, foreignKeyColumns);
}
/**
* Uniquely identifier a foreign key, so that we don't
* join it more than once, and create circularities
*/
private static final class AssociationKey {
private String[] columns;
private String table;
private AssociationKey(String[] columns, String table) {
this.columns = columns;
this.table = table;
}
@Override
public boolean equals(Object other) {
AssociationKey that = (AssociationKey) other;
return that.table.equals(table) && Arrays.equals(columns, that.columns);
}
@Override
public int hashCode() {
return table.hashCode(); //TODO: inefficient
}
}
/**
* Should we join this association?
*/
protected boolean isJoinable(
final JoinType joinType,
final Set visitedAssociationKeys,
final String lhsTable,
final String[] lhsColumnNames,
final AssociationType type,
final int depth) {
if ( joinType == JoinType.NONE ) {
return false;
}
if ( joinType == JoinType.INNER_JOIN ) {
return true;
}
Integer maxFetchDepth = getFactory().getSettings().getMaximumFetchDepth();
final boolean tooDeep = maxFetchDepth!=null && depth >= maxFetchDepth.intValue();
return !tooDeep && !isDuplicateAssociation(lhsTable, lhsColumnNames, type);
}
protected String orderBy(final List associations, final String orderBy) {
return mergeOrderings( orderBy( associations ), orderBy );
}
protected static String mergeOrderings(String ordering1, String ordering2) {
if ( ordering1.length() == 0 ) {
return ordering2;
}
else if ( ordering2.length() == 0 ) {
return ordering1;
}
else {
return ordering1 + ", " + ordering2;
}
}
/**
* Generate a sequence of <tt>LEFT OUTER JOIN clauses for the given associations.
*/
protected final JoinFragment mergeOuterJoins(List associations)
throws MappingException {
JoinFragment outerjoin = getDialect().createOuterJoinFragment();
Iterator iter = associations.iterator();
OuterJoinableAssociation last = null;
while ( iter.hasNext() ) {
OuterJoinableAssociation oj = (OuterJoinableAssociation) iter.next();
if ( last != null && last.isManyToManyWith( oj ) ) {
oj.addManyToManyJoin( outerjoin, ( QueryableCollection ) last.getJoinable() );
}
else {
oj.addJoins(outerjoin);
}
last = oj;
}
last = null;
return outerjoin;
}
/**
* Count the number of instances of Joinable which are actually
* also instances of Loadable, or are one-to-many associations
*/
protected static final int countEntityPersisters(List associations)
throws MappingException {
int result = 0;
Iterator iter = associations.iterator();
while ( iter.hasNext() ) {
OuterJoinableAssociation oj = (OuterJoinableAssociation) iter.next();
if ( oj.getJoinable().consumesEntityAlias() ) {
result++;
}
}
return result;
}
/**
* Count the number of instances of Joinable which are actually
* also instances of PersistentCollection which are being fetched
* by outer join
*/
protected static final int countCollectionPersisters(List associations)
throws MappingException {
int result = 0;
Iterator iter = associations.iterator();
while ( iter.hasNext() ) {
OuterJoinableAssociation oj = (OuterJoinableAssociation) iter.next();
if ( oj.getJoinType()==JoinType.LEFT_OUTER_JOIN &&
oj.getJoinable().isCollection() &&
! oj.hasRestriction() ) {
result++;
}
}
return result;
}
/**
* Get the order by string required for collection fetching
*/
protected static final String orderBy(List associations)
throws MappingException {
StringBuffer buf = new StringBuffer();
Iterator iter = associations.iterator();
OuterJoinableAssociation last = null;
while ( iter.hasNext() ) {
OuterJoinableAssociation oj = (OuterJoinableAssociation) iter.next();
if ( oj.getJoinType() == JoinType.LEFT_OUTER_JOIN ) { // why does this matter?
if ( oj.getJoinable().isCollection() ) {
final QueryableCollection queryableCollection = (QueryableCollection) oj.getJoinable();
if ( queryableCollection.hasOrdering() ) {
final String orderByString = queryableCollection.getSQLOrderByString( oj.getRHSAlias() );
buf.append( orderByString ).append(", ");
}
}
else {
// it might still need to apply a collection ordering based on a
// many-to-many defined order-by...
if ( last != null && last.getJoinable().isCollection() ) {
final QueryableCollection queryableCollection = (QueryableCollection) last.getJoinable();
if ( queryableCollection.isManyToMany() && last.isManyToManyWith( oj ) ) {
if ( queryableCollection.hasManyToManyOrdering() ) {
final String orderByString = queryableCollection.getManyToManyOrderByString( oj.getRHSAlias() );
buf.append( orderByString ).append(", ");
}
}
}
}
}
last = oj;
}
if ( buf.length()>0 ) buf.setLength( buf.length()-2 );
return buf.toString();
}
/**
* Render the where condition for a (batch) load by identifier / collection key
*/
protected StringBuffer whereString(String alias, String[] columnNames, int batchSize) {
if ( columnNames.length==1 ) {
// if not a composite key, use "foo in (?, ?, ?)" for batching
// if no batch, and not a composite key, use "foo = ?"
InFragment in = new InFragment().setColumn( alias, columnNames[0] );
for ( int i=0; i<batchSize; i++ ) in.addValue("?");
return new StringBuffer( in.toFragmentString() );
}
else {
//a composite key
ConditionFragment byId = new ConditionFragment()
.setTableAlias(alias)
.setCondition( columnNames, "?" );
StringBuffer whereString = new StringBuffer();
if ( batchSize==1 ) {
// if no batch, use "foo = ? and bar = ?"
whereString.append( byId.toFragmentString() );
}
else {
// if a composite key, use "( (foo = ? and bar = ?) or (foo = ? and bar = ?) )" for batching
whereString.append('('); //TODO: unnecessary for databases with ANSI-style joins
DisjunctionFragment df = new DisjunctionFragment();
for ( int i=0; i<batchSize; i++ ) {
df.addCondition(byId);
}
whereString.append( df.toFragmentString() );
whereString.append(')'); //TODO: unnecessary for databases with ANSI-style joins
}
return whereString;
}
}
protected void initPersisters(final List associations, final LockMode lockMode) throws MappingException {
initPersisters( associations, new LockOptions(lockMode));
}
protected static interface AssociationInitCallback {
public static final AssociationInitCallback NO_CALLBACK = new AssociationInitCallback() {
public void associationProcessed(OuterJoinableAssociation oja, int position) {
}
};
public void associationProcessed(OuterJoinableAssociation oja, int position);
}
protected void initPersisters(final List associations, final LockOptions lockOptions) throws MappingException {
initPersisters( associations, lockOptions, AssociationInitCallback.NO_CALLBACK );
}
protected void initPersisters(
final List associations,
final LockOptions lockOptions,
final AssociationInitCallback callback) throws MappingException {
final int joins = countEntityPersisters(associations);
final int collections = countCollectionPersisters(associations);
collectionOwners = collections==0 ? null : new int[collections];
collectionPersisters = collections==0 ? null : new CollectionPersister[collections];
collectionSuffixes = BasicLoader.generateSuffixes( joins + 1, collections );
this.lockOptions = lockOptions;
persisters = new Loadable[joins];
aliases = new String[joins];
owners = new int[joins];
ownerAssociationTypes = new EntityType[joins];
lockModeArray = ArrayHelper.fillArray( lockOptions.getLockMode(), joins );
int i=0;
int j=0;
Iterator iter = associations.iterator();
while ( iter.hasNext() ) {
final OuterJoinableAssociation oj = (OuterJoinableAssociation) iter.next();
if ( !oj.isCollection() ) {
persisters[i] = (Loadable) oj.getJoinable();
aliases[i] = oj.getRHSAlias();
owners[i] = oj.getOwner(associations);
ownerAssociationTypes[i] = (EntityType) oj.getJoinableType();
callback.associationProcessed( oj, i );
i++;
}
else {
QueryableCollection collPersister = (QueryableCollection) oj.getJoinable();
if ( oj.getJoinType()==JoinType.LEFT_OUTER_JOIN && ! oj.hasRestriction() ) {
//it must be a collection fetch
collectionPersisters[j] = collPersister;
collectionOwners[j] = oj.getOwner(associations);
j++;
}
if ( collPersister.isOneToMany() ) {
persisters[i] = (Loadable) collPersister.getElementPersister();
aliases[i] = oj.getRHSAlias();
callback.associationProcessed( oj, i );
i++;
}
}
}
if ( ArrayHelper.isAllNegative(owners) ) owners = null;
if ( collectionOwners!=null && ArrayHelper.isAllNegative(collectionOwners) ) {
collectionOwners = null;
}
}
/**
* Generate a select list of columns containing all properties of the entity classes
*/
protected final String selectString(List associations)
throws MappingException {
if ( associations.size()==0 ) {
return "";
}
else {
StringBuffer buf = new StringBuffer( associations.size() * 100 );
int entityAliasCount=0;
int collectionAliasCount=0;
for ( int i=0; i<associations.size(); i++ ) {
OuterJoinableAssociation join = (OuterJoinableAssociation) associations.get(i);
OuterJoinableAssociation next = (i == associations.size() - 1)
? null
: ( OuterJoinableAssociation ) associations.get( i + 1 );
final Joinable joinable = join.getJoinable();
final String entitySuffix = ( suffixes == null || entityAliasCount >= suffixes.length )
? null
: suffixes[entityAliasCount];
final String collectionSuffix = ( collectionSuffixes == null || collectionAliasCount >= collectionSuffixes.length )
? null
: collectionSuffixes[collectionAliasCount];
final String selectFragment = joinable.selectFragment(
next == null ? null : next.getJoinable(),
next == null ? null : next.getRHSAlias(),
join.getRHSAlias(),
entitySuffix,
collectionSuffix,
join.getJoinType()==JoinType.LEFT_OUTER_JOIN
);
if (selectFragment.trim().length() > 0) {
buf.append(", ").append(selectFragment);
}
if ( joinable.consumesEntityAlias() ) entityAliasCount++;
if ( joinable.consumesCollectionAlias() && join.getJoinType()==JoinType.LEFT_OUTER_JOIN ) collectionAliasCount++;
}
return buf.toString();
}
}
}
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