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Hibernate's core ORM functionality
/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* License: GNU Lesser General Public License (LGPL), version 2.1 or later.
* See the lgpl.txt file in the root directory or .
*/
package org.hibernate.hql.internal.classic;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import org.hibernate.QueryException;
import org.hibernate.hql.spi.QueryTranslator;
import org.hibernate.persister.entity.Queryable;
import org.hibernate.sql.JoinType;
/**
* Parses the from clause of a hibernate query, looking for tables and
* aliases for the SQL query.
*/
public class FromParser implements Parser {
private final PathExpressionParser peParser = new FromPathExpressionParser();
private String entityName;
private String alias;
private boolean afterIn;
private boolean afterAs;
private boolean afterClass;
private boolean expectingJoin;
private boolean expectingIn;
private boolean expectingAs;
private boolean afterJoinType;
private JoinType joinType = JoinType.INNER_JOIN;
private boolean afterFetch;
//support collection member declarations
//e.g. "from Customer c, in(c.orders) as o"
private boolean memberDeclarations;
private boolean expectingPathExpression;
private boolean afterMemberDeclarations;
private String collectionName;
private static final Map JOIN_TYPES = new HashMap();
static {
JOIN_TYPES.put( "left", JoinType.LEFT_OUTER_JOIN );
JOIN_TYPES.put( "right", JoinType.RIGHT_OUTER_JOIN );
JOIN_TYPES.put( "full", JoinType.FULL_JOIN );
JOIN_TYPES.put( "inner", JoinType.INNER_JOIN );
}
public void token(String token, QueryTranslatorImpl q) throws QueryException {
// start by looking for HQL keywords...
String lcToken = token.toLowerCase( Locale.ROOT );
if ( lcToken.equals( "," ) ) {
if ( !( expectingJoin | expectingAs ) ) {
throw new QueryException( "unexpected token: ," );
}
expectingJoin = false;
expectingAs = false;
}
else if ( lcToken.equals( "join" ) ) {
if ( !afterJoinType ) {
if ( !( expectingJoin | expectingAs ) ) {
throw new QueryException( "unexpected token: join" );
}
// inner joins can be abbreviated to 'join'
joinType = JoinType.INNER_JOIN;
expectingJoin = false;
expectingAs = false;
}
else {
afterJoinType = false;
}
}
else if ( lcToken.equals( "fetch" ) ) {
if ( q.isShallowQuery() ) {
throw new QueryException( QueryTranslator.ERROR_CANNOT_FETCH_WITH_ITERATE );
}
if ( joinType == JoinType.NONE ) {
throw new QueryException( "unexpected token: fetch" );
}
if ( joinType == JoinType.FULL_JOIN || joinType == JoinType.RIGHT_OUTER_JOIN ) {
throw new QueryException( "fetch may only be used with inner join or left outer join" );
}
afterFetch = true;
}
else if ( lcToken.equals( "outer" ) ) {
// 'outer' is optional and is ignored
if ( !afterJoinType ||
( joinType != JoinType.LEFT_OUTER_JOIN && joinType != JoinType.RIGHT_OUTER_JOIN )
) {
throw new QueryException( "unexpected token: outer" );
}
}
else if ( JOIN_TYPES.containsKey( lcToken ) ) {
if ( !( expectingJoin | expectingAs ) ) {
throw new QueryException( "unexpected token: " + token );
}
joinType = JOIN_TYPES.get( lcToken );
afterJoinType = true;
expectingJoin = false;
expectingAs = false;
}
else if ( lcToken.equals( "class" ) ) {
if ( !afterIn ) {
throw new QueryException( "unexpected token: class" );
}
if ( joinType != JoinType.NONE ) {
throw new QueryException( "outer or full join must be followed by path expression" );
}
afterClass = true;
}
else if ( lcToken.equals( "in" ) ) {
if ( alias == null ) {
memberDeclarations = true;
afterMemberDeclarations = false;
}
else if ( !expectingIn ) {
throw new QueryException( "unexpected token: in" );
}
else {
afterIn = true;
expectingIn = false;
}
}
else if ( lcToken.equals( "as" ) ) {
if ( !expectingAs ) {
throw new QueryException( "unexpected token: as" );
}
afterAs = true;
expectingAs = false;
}
else if ( "(".equals( token ) ) {
if ( !memberDeclarations ) {
throw new QueryException( "unexpected token: (" );
}
//TODO alias should be null here
expectingPathExpression = true;
}
else if ( ")".equals( token ) ) {
// memberDeclarations = false;
// expectingPathExpression = false;
afterMemberDeclarations = true;
}
else {
if ( afterJoinType ) {
throw new QueryException( "join expected: " + token );
}
if ( expectingJoin ) {
throw new QueryException( "unexpected token: " + token );
}
if ( expectingIn ) {
throw new QueryException( "in expected: " + token );
}
// now anything that is not a HQL keyword
if ( afterAs || expectingAs ) {
// (AS is always optional, for consistency with SQL/OQL)
// process the "new" HQL style where aliases are assigned
// _after_ the class name or path expression ie. using
// the AS construction
if ( entityName != null ) {
q.setAliasName( token, entityName );
}
else if ( collectionName != null ) {
q.setAliasName( token, collectionName );
}
else {
throw new QueryException( "unexpected: as " + token );
}
afterAs = false;
expectingJoin = true;
expectingAs = false;
entityName = null;
collectionName = null;
memberDeclarations = false;
expectingPathExpression = false;
afterMemberDeclarations = false;
}
else if ( afterIn ) {
// process the "old" HQL style where aliases appear _first_
// ie. using the IN or IN CLASS constructions
if ( alias == null ) {
throw new QueryException( "alias not specified for: " + token );
}
if ( joinType != JoinType.NONE ) {
throw new QueryException( "outer or full join must be followed by path expression" );
}
if ( afterClass ) {
// treat it as a classname
Queryable p = q.getEntityPersisterUsingImports( token );
if ( p == null ) {
throw new QueryException( "persister not found: " + token );
}
q.addFromClass( alias, p );
}
else {
// treat it as a path expression
peParser.setJoinType( JoinType.INNER_JOIN );
peParser.setUseThetaStyleJoin( true );
ParserHelper.parse( peParser, q.unalias( token ), ParserHelper.PATH_SEPARATORS, q );
if ( !peParser.isCollectionValued() ) {
throw new QueryException(
"path expression did not resolve to collection: " + token
);
}
String nm = peParser.addFromCollection( q );
q.setAliasName( alias, nm );
}
alias = null;
afterIn = false;
afterClass = false;
expectingJoin = true;
}
else if ( memberDeclarations && expectingPathExpression ) {
expectingAs = true;
peParser.setJoinType( JoinType.INNER_JOIN );
peParser.setUseThetaStyleJoin( false );
ParserHelper.parse( peParser, q.unalias( token ), ParserHelper.PATH_SEPARATORS, q );
if ( !peParser.isCollectionValued() ) {
throw new QueryException( "path expression did not resolve to collection: " + token );
}
collectionName = peParser.addFromCollection( q );
expectingPathExpression = false;
memberDeclarations = false;
}
else {
// handle a path expression or class name that
// appears at the start, in the "new" HQL
// style or an alias that appears at the start
// in the "old" HQL style
Queryable p = q.getEntityPersisterUsingImports( token );
if ( p != null ) {
// starts with the name of a mapped class (new style)
if ( joinType != JoinType.NONE ) {
throw new QueryException( "outer or full join must be followed by path expression" );
}
entityName = q.createNameFor( p.getEntityName() );
q.addFromClass( entityName, p );
expectingAs = true;
}
else if ( token.indexOf( '.' ) < 0 ) {
// starts with an alias (old style)
// semi-bad thing about this: can't re-alias another alias.....
alias = token;
expectingIn = true;
}
else {
// starts with a path expression (new style)
// force HQL style: from Person p inner join p.cars c
//if (joinType==NONE) throw new QueryException("path expression must be preceded by full, left, right or inner join");
//allow ODMG OQL style: from Person p, p.cars c
if ( joinType != JoinType.NONE ) {
peParser.setJoinType( joinType );
}
else {
peParser.setJoinType( JoinType.INNER_JOIN );
}
peParser.setUseThetaStyleJoin( q.isSubquery() );
ParserHelper.parse( peParser, q.unalias( token ), ParserHelper.PATH_SEPARATORS, q );
entityName = peParser.addFromAssociation( q );
joinType = JoinType.NONE;
peParser.setJoinType( JoinType.INNER_JOIN );
if ( afterFetch ) {
peParser.fetch( q, entityName );
afterFetch = false;
}
expectingAs = true;
}
}
}
}
public void start(QueryTranslatorImpl q) {
entityName = null;
collectionName = null;
alias = null;
afterIn = false;
afterAs = false;
afterClass = false;
expectingJoin = false;
expectingIn = false;
expectingAs = false;
memberDeclarations = false;
expectingPathExpression = false;
afterMemberDeclarations = false;
joinType = JoinType.NONE;
}
public void end(QueryTranslatorImpl q) {
if ( afterMemberDeclarations ) {
//The exception throwned by the AST query translator contains the error token location, respensent by line and colum,
//but it hard to get that info here.
throw new QueryException( "alias not specified for IN" );
}
}
}