querytranslatorimpl.java

一个Java持久层类库

	private Queryable getEntityPersisterForName(String name) throws QueryException {
		String type = getType( name );
		Queryable persister = getEntityPersister( type );
		if ( persister == null ) throw new QueryException( "persistent class not found: " + type );
		return persister;
	}

	Queryable getEntityPersisterUsingImports(String className) {
		final String importedClassName = getFactory().getImportedClassName( className );
		if ( importedClassName == null ) {
			return null;
		}
		try {
			return ( Queryable ) getFactory().getEntityPersister( importedClassName );
		}
		catch ( MappingException me ) {
			return null;
		}
	}

	Queryable getEntityPersister(String entityName) throws QueryException {
		try {
			return ( Queryable ) getFactory().getEntityPersister( entityName );
		}
		catch ( Exception e ) {
			throw new QueryException( "persistent class not found: " + entityName );
		}
	}

	QueryableCollection getCollectionPersister(String role) throws QueryException {
		try {
			return ( QueryableCollection ) getFactory().getCollectionPersister( role );
		}
		catch ( ClassCastException cce ) {
			throw new QueryException( "collection role is not queryable: " + role );
		}
		catch ( Exception e ) {
			throw new QueryException( "collection role not found: " + role );
		}
	}

	void addType(String name, String type) {
		typeMap.put( name, type );
	}

	void addCollection(String name, String role) {
		collections.put( name, role );
	}

	void addFrom(String name, String type, JoinSequence joinSequence)
			throws QueryException {
		addType( name, type );
		addFrom( name, joinSequence );
	}

	void addFromCollection(String name, String collectionRole, JoinSequence joinSequence)
			throws QueryException {
		//register collection role
		addCollection( name, collectionRole );
		addJoin( name, joinSequence );
	}

	void addFrom(String name, JoinSequence joinSequence)
			throws QueryException {
		fromTypes.add( name );
		addJoin( name, joinSequence );
	}

	void addFromClass(String name, Queryable classPersister)
			throws QueryException {
		JoinSequence joinSequence = new JoinSequence( getFactory() )
				.setRoot( classPersister, name );
		//crossJoins.add(name);
		addFrom( name, classPersister.getEntityName(), joinSequence );
	}

	void addSelectClass(String name) {
		returnedTypes.add( name );
	}

	void addSelectScalar(Type type) {
		scalarTypes.add( type );
	}

	void appendWhereToken(String token) {
		whereTokens.add( token );
	}

	void appendHavingToken(String token) {
		havingTokens.add( token );
	}

	void appendOrderByToken(String token) {
		orderByTokens.add( token );
	}

	void appendGroupByToken(String token) {
		groupByTokens.add( token );
	}

	void appendScalarSelectToken(String token) {
		scalarSelectTokens.add( token );
	}

	void appendScalarSelectTokens(String[] tokens) {
		scalarSelectTokens.add( tokens );
	}

	void addFromJoinOnly(String name, JoinSequence joinSequence) throws QueryException {
		addJoin( name, joinSequence.getFromPart() );
	}

	void addJoin(String name, JoinSequence joinSequence) throws QueryException {
		if ( !joins.containsKey( name ) ) joins.put( name, joinSequence );
	}

	void addNamedParameter(String name) {
		if ( superQuery != null ) superQuery.addNamedParameter( name );
		Integer loc = new Integer( parameterCount++ );
		Object o = namedParameters.get( name );
		if ( o == null ) {
			namedParameters.put( name, loc );
		}
		else if ( o instanceof Integer ) {
			ArrayList list = new ArrayList( 4 );
			list.add( o );
			list.add( loc );
			namedParameters.put( name, list );
		}
		else {
			( ( ArrayList ) o ).add( loc );
		}
	}

	public int[] getNamedParameterLocs(String name) throws QueryException {
		Object o = namedParameters.get( name );
		if ( o == null ) {
			QueryException qe = new QueryException( ERROR_NAMED_PARAMETER_DOES_NOT_APPEAR + name );
			qe.setQueryString( queryString );
			throw qe;
		}
		if ( o instanceof Integer ) {
			return new int[]{ ( ( Integer ) o ).intValue() };
		}
		else {
			return ArrayHelper.toIntArray( ( ArrayList ) o );
		}
	}

	private void renderSQL() throws QueryException, MappingException {

		final int rtsize;
		if ( returnedTypes.size() == 0 && scalarTypes.size() == 0 ) {
			//ie no select clause in HQL
			returnedTypes = fromTypes;
			rtsize = returnedTypes.size();
		}
		else {
			rtsize = returnedTypes.size();
			Iterator iter = entitiesToFetch.iterator();
			while ( iter.hasNext() ) {
				returnedTypes.add( iter.next() );
			}
		}
		int size = returnedTypes.size();
		persisters = new Queryable[size];
		names = new String[size];
		owners = new int[size];
		ownerAssociationTypes = new EntityType[size];
		suffixes = new String[size];
		includeInSelect = new boolean[size];
		for ( int i = 0; i < size; i++ ) {
			String name = ( String ) returnedTypes.get( i );
			//if ( !isName(name) ) throw new QueryException("unknown type: " + name);
			persisters[i] = getEntityPersisterForName( name );
			// TODO: cannot use generateSuffixes() - it handles the initial suffix differently.
			suffixes[i] = ( size == 1 ) ? "" : Integer.toString( i ) + '_';
			names[i] = name;
			includeInSelect[i] = !entitiesToFetch.contains( name );
			if ( includeInSelect[i] ) selectLength++;
			if ( name.equals( collectionOwnerName ) ) collectionOwnerColumn = i;
			String oneToOneOwner = ( String ) oneToOneOwnerNames.get( name );
			owners[i] = ( oneToOneOwner == null ) ? -1 : returnedTypes.indexOf( oneToOneOwner );
			ownerAssociationTypes[i] = (EntityType) uniqueKeyOwnerReferences.get( name );
		}

		if ( ArrayHelper.isAllNegative( owners ) ) owners = null;

		String scalarSelect = renderScalarSelect(); //Must be done here because of side-effect! yuck...

		int scalarSize = scalarTypes.size();
		hasScalars = scalarTypes.size() != rtsize;

		returnTypes = new Type[scalarSize];
		for ( int i = 0; i < scalarSize; i++ ) {
			returnTypes[i] = ( Type ) scalarTypes.get( i );
		}

		QuerySelect sql = new QuerySelect( getFactory().getDialect() );
		sql.setDistinct( distinct );

		if ( !shallowQuery ) {
			renderIdentifierSelect( sql );
			renderPropertiesSelect( sql );
		}

		if ( collectionPersister != null ) {
			sql.addSelectFragmentString( collectionPersister.selectFragment( fetchName, "__" ) );
		}

		if ( hasScalars || shallowQuery ) sql.addSelectFragmentString( scalarSelect );

		//TODO: for some dialects it would be appropriate to add the renderOrderByPropertiesSelect() to other select strings
		mergeJoins( sql.getJoinFragment() );

		sql.setWhereTokens( whereTokens.iterator() );

		sql.setGroupByTokens( groupByTokens.iterator() );
		sql.setHavingTokens( havingTokens.iterator() );
		sql.setOrderByTokens( orderByTokens.iterator() );

		if ( collectionPersister != null && collectionPersister.hasOrdering() ) {
			sql.addOrderBy( collectionPersister.getSQLOrderByString( fetchName ) );
		}

		scalarColumnNames = NameGenerator.generateColumnNames( returnTypes, getFactory() );

		// initialize the Set of queried identifier spaces (ie. tables)
		Iterator iter = collections.values().iterator();
		while ( iter.hasNext() ) {
			CollectionPersister p = getCollectionPersister( ( String ) iter.next() );
			addQuerySpaces( p.getCollectionSpaces() );
		}
		iter = typeMap.keySet().iterator();
		while ( iter.hasNext() ) {
			Queryable p = getEntityPersisterForName( ( String ) iter.next() );
			addQuerySpaces( p.getQuerySpaces() );
		}

		sqlString = sql.toQueryString();

		if ( holderClass != null ) holderConstructor = ReflectHelper.getConstructor( holderClass, returnTypes );

		if ( hasScalars ) {
			actualReturnTypes = returnTypes;
		}
		else {
			actualReturnTypes = new Type[selectLength];
			int j = 0;
			for ( int i = 0; i < persisters.length; i++ ) {
				if ( includeInSelect[i] ) {
					actualReturnTypes[j++] = TypeFactory.manyToOne( persisters[i].getEntityName(), shallowQuery );
				}
			}
		}

	}

	private void renderIdentifierSelect(QuerySelect sql) {
		int size = returnedTypes.size();

		for ( int k = 0; k < size; k++ ) {
			String name = ( String ) returnedTypes.get( k );
			String suffix = size == 1 ? "" : Integer.toString( k ) + '_';
			sql.addSelectFragmentString( persisters[k].identifierSelectFragment( name, suffix ) );
		}

	}

	/*private String renderOrderByPropertiesSelect() {
		StringBuffer buf = new StringBuffer(10);

		//add the columns we are ordering by to the select ID select clause
		Iterator iter = orderByTokens.iterator();
		while ( iter.hasNext() ) {
			String token = (String) iter.next();
			if ( token.lastIndexOf(".") > 0 ) {
				//ie. it is of form "foo.bar", not of form "asc" or "desc"
				buf.append(StringHelper.COMMA_SPACE).append(token);
			}
		}

		return buf.toString();
	}*/

	private void renderPropertiesSelect(QuerySelect sql) {
		int size = returnedTypes.size();
		for ( int k = 0; k < size; k++ ) {
			String suffix = size == 1 ? "" : Integer.toString( k ) + '_';
			String name = ( String ) returnedTypes.get( k );
			sql.addSelectFragmentString( persisters[k].propertySelectFragment( name, suffix, false ) );
		}
	}

	/**
	 * WARNING: side-effecty
	 */
	private String renderScalarSelect() {

		boolean isSubselect = superQuery != null;

		StringBuffer buf = new StringBuffer( 20 );

		if ( scalarTypes.size() == 0 ) {
			//ie. no select clause
			int size = returnedTypes.size();
			for ( int k = 0; k < size; k++ ) {

				scalarTypes.add( TypeFactory.manyToOne( persisters[k].getEntityName(), shallowQuery ) );

				String[] idColumnNames = persisters[k].getIdentifierColumnNames();
				for ( int i = 0; i < idColumnNames.length; i++ ) {
					buf.append( returnedTypes.get( k ) ).append( '.' ).append( idColumnNames[i] );
					if ( !isSubselect ) buf.append( " as " ).append( NameGenerator.scalarName( k, i ) );
					if ( i != idColumnNames.length - 1 || k != size - 1 ) buf.append( ", " );
				}

			}

		}
		else {
			//there _was_ a select clause
			Iterator iter = scalarSelectTokens.iterator();
			int c = 0;
			boolean nolast = false; //real hacky...
			int parenCount = 0; // used to count the nesting of parentheses
			while ( iter.hasNext() ) {
				Object next = iter.next();
				if ( next instanceof String ) {
					String token = ( String ) next;

					if ( "(".equals( token ) ) {
						parenCount++;
					}
					else if ( ")".equals( token ) ) {
						parenCount--;
					}

					String lc = token.toLowerCase();
					if ( lc.equals( ", " ) ) {
						if ( nolast ) {
							nolast = false;
						}
						else {
							if ( !isSubselect && parenCount == 0 ) {
								int x = c++;
								buf.append( " as " )
										.append( NameGenerator.scalarName( x, 0 ) );
							}
						}
					}
					buf.append( token );
					if ( lc.equals( "distinct" ) || lc.equals( "all" ) ) {
						buf.append( ' ' );
					}
				}
				else {
					nolast = true;
					String[] tokens = ( String[] ) next;
					for ( int i = 0; i < tokens.length; i++ ) {
						buf.append( tokens[i] );
						if ( !isSubselect ) {
							buf.append( " as " )
									.append( NameGenerator.scalarName( c, i ) );
						}
						if ( i != tokens.length - 1 ) buf.append( ", " );
					}
					c++;
				}
			}
			if ( !isSubselect && !nolast ) {
				int x = c++;
				buf.append( " as " )
						.append( NameGenerator.scalarName( x, 0 ) );
			}

		}

		return buf.toString();
	}

	private void mergeJoins(JoinFragment ojf) throws MappingException, QueryException {

		Iterator iter = joins.entrySet().iterator();
		while ( iter.hasNext() ) {
			Map.Entry me = ( Map.Entry ) iter.next();
			String name = ( String ) me.getKey();