Hibernate example source code file (FromElement.java)

This example Hibernate source code file (FromElement.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Hibernate tags/keywords

entitypersister, from, from, fromclause, fromelement, fromelement, illegalstateexception, parameterspecification, queryable, queryable, string, string, type, typediscriminatormetadata, util

The Hibernate FromElement.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008, Red Hat Middleware LLC 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 Middleware LLC.
 *
 * 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.hql.internal.ast.tree;

import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;

import org.hibernate.engine.internal.JoinSequence;
import org.hibernate.hql.spi.QueryTranslator;
import org.hibernate.internal.CoreMessageLogger;
import org.hibernate.QueryException;
import org.hibernate.hql.internal.CollectionProperties;
import org.hibernate.hql.internal.antlr.HqlSqlTokenTypes;
import org.hibernate.hql.internal.antlr.SqlTokenTypes;
import org.hibernate.hql.internal.ast.TypeDiscriminatorMetadata;
import org.hibernate.hql.internal.ast.util.ASTUtil;
import org.hibernate.internal.util.StringHelper;
import org.hibernate.param.ParameterSpecification;
import org.hibernate.persister.collection.QueryableCollection;
import org.hibernate.persister.entity.DiscriminatorMetadata;
import org.hibernate.persister.entity.EntityPersister;
import org.hibernate.persister.entity.PropertyMapping;
import org.hibernate.persister.entity.Queryable;
import org.hibernate.type.EntityType;
import org.hibernate.type.Type;
import org.jboss.logging.Logger;

/**
 * Represents a single mapped class mentioned in an HQL FROM clause.  Each
 * class reference will have the following symbols:
 * <ul>
 * <li>A class name - This is the name of the Java class that is mapped by Hibernate.
 * <li>[optional] an HQL alias for the mapped class.
 * <li>A table name - The name of the table that is mapped to the Java class.
 * <li>A table alias - The alias for the table that will be used in the resulting SQL.
 * </ul>
 *
 * @author josh
 */
public class FromElement extends HqlSqlWalkerNode implements DisplayableNode, ParameterContainer {

    private static final CoreMessageLogger LOG = Logger.getMessageLogger(CoreMessageLogger.class, FromElement.class.getName());

	private String className;
	private String classAlias;
	private String tableAlias;
	private String collectionTableAlias;
	private FromClause fromClause;
	private boolean includeSubclasses = true;
	private boolean collectionJoin = false;
	private FromElement origin;
	private String[] columns;
	private String role;
	private boolean fetch;
	private boolean isAllPropertyFetch;
	private boolean filter = false;
	private int sequence = -1;
	private boolean useFromFragment = false;
	private boolean initialized = false;
	private FromElementType elementType;
	private boolean useWhereFragment = true;
	private List destinations = new LinkedList();
	private boolean manyToMany = false;
	private String withClauseFragment = null;
	private String withClauseJoinAlias;
	private boolean dereferencedBySuperclassProperty;
	private boolean dereferencedBySubclassProperty;

	public FromElement() {
	}

	/**
	 * Constructor form used to initialize {@link ComponentJoin}
	 *
	 * @param fromClause The FROM clause to which this element belongs
	 * @param origin The origin (LHS) of this element
	 * @param alias The alias applied to this element
	 */
	protected FromElement(
			FromClause fromClause,
			FromElement origin,
			String alias) {
		this.fromClause = fromClause;
		this.origin = origin;
		this.classAlias = alias;
		this.tableAlias = origin.getTableAlias();
		super.initialize( fromClause.getWalker() );
	}

	protected void initializeComponentJoin(FromElementType elementType) {
		this.elementType = elementType;
		fromClause.registerFromElement( this );
		initialized = true;
	}

	public String getCollectionSuffix() {
		return elementType.getCollectionSuffix();
	}

	public void setCollectionSuffix(String suffix) {
		elementType.setCollectionSuffix(suffix);
	}

	public void initializeCollection(FromClause fromClause, String classAlias, String tableAlias) {
		doInitialize( fromClause, tableAlias, null, classAlias, null, null );
		initialized = true;
	}

	public void initializeEntity(
	        FromClause fromClause,
	        String className,
	        EntityPersister persister,
	        EntityType type,
	        String classAlias,
	        String tableAlias) {
		doInitialize( fromClause, tableAlias, className, classAlias, persister, type );
		this.sequence = fromClause.nextFromElementCounter();
		initialized = true;
	}

	private void doInitialize(FromClause fromClause, String tableAlias, String className, String classAlias,
							  EntityPersister persister, EntityType type) {
		if ( initialized ) {
			throw new IllegalStateException( "Already initialized!!" );
		}
		this.fromClause = fromClause;
		this.tableAlias = tableAlias;
		this.className = className;
		this.classAlias = classAlias;
		this.elementType = new FromElementType( this, persister, type );
		// Register the FromElement with the FROM clause, now that we have the names and aliases.
		fromClause.registerFromElement( this );
        LOG.debugf("%s : %s (%s) -> %s", fromClause, className, classAlias == null ? "<no alias>" : classAlias, tableAlias);
	}

	public EntityPersister getEntityPersister() {
		return elementType.getEntityPersister();
	}

	@Override
    public Type getDataType() {
		return elementType.getDataType();
	}

	public Type getSelectType() {
		return elementType.getSelectType();
	}

	public Queryable getQueryable() {
		return elementType.getQueryable();
	}

	public String getClassName() {
		return className;
	}

	public String getClassAlias() {
		return classAlias;
		//return classAlias == null ? className : classAlias;
	}

	private String getTableName() {
		Queryable queryable = getQueryable();
		return ( queryable != null ) ? queryable.getTableName() : "{none}";
	}

	public String getTableAlias() {
		return tableAlias;
	}

	/**
	 * Render the identifier select, but in a 'scalar' context (i.e. generate the column alias).
	 *
	 * @param i the sequence of the returned type
	 * @return the identifier select with the column alias.
	 */
	String renderScalarIdentifierSelect(int i) {
		return elementType.renderScalarIdentifierSelect( i );
	}

	void checkInitialized() {
		if ( !initialized ) {
			throw new IllegalStateException( "FromElement has not been initialized!" );
		}
	}

	/**
	 * Returns the identifier select SQL fragment.
	 *
	 * @param size The total number of returned types.
	 * @param k    The sequence of the current returned type.
	 * @return the identifier select SQL fragment.
	 */
	String renderIdentifierSelect(int size, int k) {
		return elementType.renderIdentifierSelect( size, k );
	}

	/**
	 * Returns the property select SQL fragment.
	 *
	 * @param size The total number of returned types.
	 * @param k    The sequence of the current returned type.
	 * @return the property select SQL fragment.
	 */
	String renderPropertySelect(int size, int k) {
		return elementType.renderPropertySelect( size, k, isAllPropertyFetch );
	}

	String renderCollectionSelectFragment(int size, int k) {
		return elementType.renderCollectionSelectFragment( size, k );
	}

	String renderValueCollectionSelectFragment(int size, int k) {
		return elementType.renderValueCollectionSelectFragment( size, k );
	}

	public FromClause getFromClause() {
		return fromClause;
	}

	/**
	 * Returns true if this FromElement was implied by a path, or false if this FROM element is explicitly declared in
	 * the FROM clause.
	 *
	 * @return true if this FromElement was implied by a path, or false if this FROM element is explicitly declared
	 */
	public boolean isImplied() {
		return false;	// This is an explicit FROM element.
	}

	/**
	 * Returns additional display text for the AST node.
	 *
	 * @return String - The additional display text.
	 */
	public String getDisplayText() {
		StringBuffer buf = new StringBuffer();
		buf.append( "FromElement{" );
		appendDisplayText( buf );
		buf.append( "}" );
		return buf.toString();
	}

	protected void appendDisplayText(StringBuffer buf) {
		buf.append( isImplied() ? (
				isImpliedInFromClause() ? "implied in FROM clause" : "implied" )
				: "explicit" );
		buf.append( "," ).append( isCollectionJoin() ? "collection join" : "not a collection join" );
		buf.append( "," ).append( fetch ? "fetch join" : "not a fetch join" );
		buf.append( "," ).append( isAllPropertyFetch ? "fetch all properties" : "fetch non-lazy properties" );
		buf.append( ",classAlias=" ).append( getClassAlias() );
		buf.append( ",role=" ).append( role );
		buf.append( ",tableName=" ).append( getTableName() );
		buf.append( ",tableAlias=" ).append( getTableAlias() );
		FromElement origin = getRealOrigin();
		buf.append( ",origin=" ).append( origin == null ? "null" : origin.getText() );
		buf.append( ",columns={" );
		if ( columns != null ) {
			for ( int i = 0; i < columns.length; i++ ) {
				buf.append( columns[i] );
				if ( i < columns.length ) {
					buf.append( " " );
				}
			}
		}
		buf.append( ",className=" ).append( className );
		buf.append( "}" );
	}

	@Override
    public int hashCode() {
		return super.hashCode();
	}

	@Override
    public boolean equals(Object obj) {
		return super.equals( obj );
	}


	public void setJoinSequence(JoinSequence joinSequence) {
		elementType.setJoinSequence( joinSequence );
	}

	public JoinSequence getJoinSequence() {
		return elementType.getJoinSequence();
	}

	public void setIncludeSubclasses(boolean includeSubclasses) {
        if (LOG.isTraceEnabled() && isDereferencedBySuperclassOrSubclassProperty() && !includeSubclasses) LOG.trace("Attempt to disable subclass-inclusions : "
                                                                                                                    + new Exception(
                                                                                                                                    "Stack-trace source"));
		this.includeSubclasses = includeSubclasses;
	}

	public boolean isIncludeSubclasses() {
		return includeSubclasses;
	}

	public boolean isDereferencedBySuperclassOrSubclassProperty() {
		return dereferencedBySubclassProperty || dereferencedBySuperclassProperty;
	}

	public String getIdentityColumn() {
		checkInitialized();
		String table = getTableAlias();
		if ( table == null ) {
			throw new IllegalStateException( "No table alias for node " + this );
		}
		String[] cols;
		String propertyName;
		if ( getEntityPersister() != null && getEntityPersister().getEntityMetamodel() != null
				&& getEntityPersister().getEntityMetamodel().hasNonIdentifierPropertyNamedId() ) {
			propertyName = getEntityPersister().getIdentifierPropertyName();
		}
		else {
			propertyName = EntityPersister.ENTITY_ID;
		}
		if ( getWalker().getStatementType() == HqlSqlTokenTypes.SELECT ) {
			cols = getPropertyMapping( propertyName ).toColumns( table, propertyName );
		}
		else {
			cols = getPropertyMapping( propertyName ).toColumns( propertyName );
		}
		String result = StringHelper.join( ", ", cols );
		return  cols.length == 1 ? result : "(" + result + ")";
	}

	public void setCollectionJoin(boolean collectionJoin) {
		this.collectionJoin = collectionJoin;
	}

	public boolean isCollectionJoin() {
		return collectionJoin;
	}

	public void setRole(String role) {
		this.role = role;
	}

	public void setQueryableCollection(QueryableCollection queryableCollection) {
		elementType.setQueryableCollection( queryableCollection );
	}

	public QueryableCollection getQueryableCollection() {
		return elementType.getQueryableCollection();
	}

	public void setColumns(String[] columns) {
		this.columns = columns;
	}

	public void setOrigin(FromElement origin, boolean manyToMany) {
		this.origin = origin;
		this.manyToMany = manyToMany;
		origin.addDestination( this );
		if ( origin.getFromClause() == this.getFromClause() ) {
			// TODO: Figure out a better way to get the FROM elements in a proper tree structure.
			// If this is not the destination of a many-to-many, add it as a child of the origin.
			if ( manyToMany ) {
				ASTUtil.appendSibling( origin, this );
			}
			else {
				if ( !getWalker().isInFrom() && !getWalker().isInSelect() ) {
					getFromClause().addChild( this );
				}
				else {
					origin.addChild( this );
				}
			}
		}
		else if ( !getWalker().isInFrom() ) {
			// HHH-276 : implied joins in a subselect where clause - The destination needs to be added
			// to the destination's from clause.
			getFromClause().addChild( this );	// Not sure if this is will fix everything, but it works.
		}
		else {
			// Otherwise, the destination node was implied by the FROM clause and the FROM clause processor
			// will automatically add it in the right place.
		}
	}

	public boolean isManyToMany() {
		return manyToMany;
	}

	private void addDestination(FromElement fromElement) {
		destinations.add( fromElement );
	}

	public List getDestinations() {
		return destinations;
	}

	public FromElement getOrigin() {
		return origin;
	}

	public FromElement getRealOrigin() {
		if ( origin == null ) {
			return null;
		}
		if ( origin.getText() == null || "".equals( origin.getText() ) ) {
			return origin.getRealOrigin();
		}
		return origin;
	}

	public static final String DISCRIMINATOR_PROPERTY_NAME = "class";
	private TypeDiscriminatorMetadata typeDiscriminatorMetadata;

	private static class TypeDiscriminatorMetadataImpl implements TypeDiscriminatorMetadata {
		private final DiscriminatorMetadata persisterDiscriminatorMetadata;
		private final String alias;

		private TypeDiscriminatorMetadataImpl(
				DiscriminatorMetadata persisterDiscriminatorMetadata,
				String alias) {
			this.persisterDiscriminatorMetadata = persisterDiscriminatorMetadata;
			this.alias = alias;
		}

		/**
		 * {@inheritDoc}
		 */
		public String getSqlFragment() {
			return persisterDiscriminatorMetadata.getSqlFragment( alias );
		}

		/**
		 * {@inheritDoc}
		 */
		public Type getResolutionType() {
			return persisterDiscriminatorMetadata.getResolutionType();
		}
	}

	public TypeDiscriminatorMetadata getTypeDiscriminatorMetadata() {
		if ( typeDiscriminatorMetadata == null ) {
			typeDiscriminatorMetadata = buildTypeDiscriminatorMetadata();
		}
		return typeDiscriminatorMetadata;
	}

	private TypeDiscriminatorMetadata buildTypeDiscriminatorMetadata() {
		final String aliasToUse = getTableAlias();
		Queryable queryable = getQueryable();
		if ( queryable == null ) {
			QueryableCollection collection = getQueryableCollection();
			if ( ! collection.getElementType().isEntityType() ) {
				throw new QueryException( "type discrimination cannot be applied to value collection [" + collection.getRole() + "]" );
			}
			queryable = (Queryable) collection.getElementPersister();
		}

		handlePropertyBeingDereferenced( getDataType(), DISCRIMINATOR_PROPERTY_NAME );

		return new TypeDiscriminatorMetadataImpl( queryable.getTypeDiscriminatorMetadata(), aliasToUse );
	}

	public Type getPropertyType(String propertyName, String propertyPath) {
		return elementType.getPropertyType( propertyName, propertyPath );
	}

	public String[] toColumns(String tableAlias, String path, boolean inSelect) {
		return elementType.toColumns( tableAlias, path, inSelect );
	}

	public String[] toColumns(String tableAlias, String path, boolean inSelect, boolean forceAlias) {
		return elementType.toColumns( tableAlias, path, inSelect, forceAlias );
	}

	public PropertyMapping getPropertyMapping(String propertyName) {
		return elementType.getPropertyMapping( propertyName );
	}

	public void setFetch(boolean fetch) {
		this.fetch = fetch;
		// Fetch can't be used with scroll() or iterate().
		if ( fetch && getWalker().isShallowQuery() ) {
			throw new QueryException( QueryTranslator.ERROR_CANNOT_FETCH_WITH_ITERATE );
		}
	}

	public boolean isFetch() {
		return fetch;
	}

	public int getSequence() {
		return sequence;
	}

	public void setFilter(boolean b) {
		filter = b;
	}

	public boolean isFilter() {
		return filter;
	}

	public boolean useFromFragment() {
		checkInitialized();
		// If it's not implied or it is implied and it's a many to many join where the target wasn't found.
		return !isImplied() || this.useFromFragment;
	}

	public void setUseFromFragment(boolean useFromFragment) {
		this.useFromFragment = useFromFragment;
	}

	public boolean useWhereFragment() {
		return useWhereFragment;
	}

	public void setUseWhereFragment(boolean b) {
		useWhereFragment = b;
	}


	public void setCollectionTableAlias(String collectionTableAlias) {
		this.collectionTableAlias = collectionTableAlias;
	}

	public String getCollectionTableAlias() {
		return collectionTableAlias;
	}

	public boolean isCollectionOfValuesOrComponents() {
		return elementType.isCollectionOfValuesOrComponents();
	}

	public boolean isEntity() {
		return elementType.isEntity();
	}

	public void setImpliedInFromClause(boolean flag) {
		throw new UnsupportedOperationException( "Explicit FROM elements can't be implied in the FROM clause!" );
	}

	public boolean isImpliedInFromClause() {
		return false;	// Since this is an explicit FROM element, it can't be implied in the FROM clause.
	}

	public void setInProjectionList(boolean inProjectionList) {
		// Do nothing, eplicit from elements are *always* in the projection list.
	}

	public boolean inProjectionList() {
		return !isImplied() && isFromOrJoinFragment();
	}

	public boolean isFromOrJoinFragment() {
		return getType() == SqlTokenTypes.FROM_FRAGMENT || getType() == SqlTokenTypes.JOIN_FRAGMENT;
	}

	public boolean isAllPropertyFetch() {
		return isAllPropertyFetch;
	}

	public void setAllPropertyFetch(boolean fetch) {
		isAllPropertyFetch = fetch;
	}

	public String getWithClauseFragment() {
		return withClauseFragment;
	}

	public String getWithClauseJoinAlias() {
		return withClauseJoinAlias;
	}

	public void setWithClauseFragment(String withClauseJoinAlias, String withClauseFragment) {
		this.withClauseJoinAlias = withClauseJoinAlias;
		this.withClauseFragment = withClauseFragment;
	}

	public boolean hasCacheablePersister() {
		if ( getQueryableCollection() != null ) {
			return getQueryableCollection().hasCache();
		}
		else {
			return getQueryable().hasCache();
		}
	}

	public void handlePropertyBeingDereferenced(Type propertySource, String propertyName) {
		if ( getQueryableCollection() != null && CollectionProperties.isCollectionProperty( propertyName ) ) {
			// propertyName refers to something like collection.size...
			return;
		}
		if ( propertySource.isComponentType() ) {
			// property name is a sub-path of a component...
			return;
		}

		Queryable persister = getQueryable();
		if ( persister != null ) {
			try {
				Queryable.Declarer propertyDeclarer = persister.getSubclassPropertyDeclarer( propertyName );
                LOG.trace("Handling property dereference [" + persister.getEntityName() + " (" + getClassAlias() + ") -> "
                          + propertyName + " (" + propertyDeclarer + ")]");
				if ( propertyDeclarer == Queryable.Declarer.SUBCLASS ) {
					dereferencedBySubclassProperty = true;
					includeSubclasses = true;
				}
				else if ( propertyDeclarer == Queryable.Declarer.SUPERCLASS ) {
					dereferencedBySuperclassProperty = true;
				}
			}
			catch( QueryException ignore ) {
				// ignore it; the incoming property could not be found so we
				// cannot be sure what to do here.  At the very least, the
				// safest is to simply not apply any dereference toggling...

			}
		}
	}

	public boolean isDereferencedBySuperclassProperty() {
		return dereferencedBySuperclassProperty;
	}

	public boolean isDereferencedBySubclassProperty() {
		return dereferencedBySubclassProperty;
	}


	// ParameterContainer impl ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	private List embeddedParameters;

	public void addEmbeddedParameter(ParameterSpecification specification) {
		if ( embeddedParameters == null ) {
			embeddedParameters = new ArrayList();
		}
		embeddedParameters.add( specification );
	}

	public boolean hasEmbeddedParameters() {
		return embeddedParameters != null && ! embeddedParameters.isEmpty();
	}

	public ParameterSpecification[] getEmbeddedParameters() {
		return ( ParameterSpecification[] ) embeddedParameters.toArray( new ParameterSpecification[ embeddedParameters.size() ] );
	}

	public ParameterSpecification getIndexCollectionSelectorParamSpec() {
		return elementType.getIndexCollectionSelectorParamSpec();
	}

	public void setIndexCollectionSelectorParamSpec(ParameterSpecification indexCollectionSelectorParamSpec) {
		if ( indexCollectionSelectorParamSpec == null ) {
			if ( elementType.getIndexCollectionSelectorParamSpec() != null ) {
				embeddedParameters.remove( elementType.getIndexCollectionSelectorParamSpec() );
				elementType.setIndexCollectionSelectorParamSpec( null );
			}
		}
		else {
			elementType.setIndexCollectionSelectorParamSpec( indexCollectionSelectorParamSpec );
			addEmbeddedParameter( indexCollectionSelectorParamSpec );
		}
	}
}