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//$Id: WhereParser.java 7825 2005-08-10 20:23:55Z oneovthafew $
package org.hibernate.hql.classic;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;
import org.hibernate.MappingException;
import org.hibernate.QueryException;
import org.hibernate.engine.JoinSequence;
import org.hibernate.hql.QueryTranslator;
import org.hibernate.persister.collection.CollectionPropertyNames;
import org.hibernate.persister.entity.Queryable;
import org.hibernate.sql.InFragment;
import org.hibernate.type.EntityType;
import org.hibernate.type.LiteralType;
import org.hibernate.type.Type;
import org.hibernate.type.TypeFactory;
import org.hibernate.util.ReflectHelper;
import org.hibernate.util.StringHelper;
/**
* Parses the where clause of a hibernate query and translates it to an
* SQL where clause.
*/
// We should reengineer this class so that, rather than the current ad -
// hoc linear approach to processing a stream of tokens, we instead
// build up a tree of expressions.
// We would probably refactor to have LogicParser (builds a tree of simple
// expressions connected by and, or, not), ExpressionParser (translates
// from OO terms like foo, foo.Bar, foo.Bar.Baz to SQL terms like
// FOOS.ID, FOOS.BAR_ID, etc) and PathExpressionParser (which does much
// the same thing it does now)
public class WhereParser implements Parser {
private final PathExpressionParser pathExpressionParser;
{
pathExpressionParser = new PathExpressionParser();
pathExpressionParser.setUseThetaStyleJoin( true ); //Need this, since join condition can appear inside parens!
}
private static final Set EXPRESSION_TERMINATORS = new HashSet(); //tokens that close a sub expression
private static final Set EXPRESSION_OPENERS = new HashSet(); //tokens that open a sub expression
private static final Set BOOLEAN_OPERATORS = new HashSet(); //tokens that would indicate a sub expression is a boolean expression
private static final Map NEGATIONS = new HashMap();
static {
EXPRESSION_TERMINATORS.add( "and" );
EXPRESSION_TERMINATORS.add( "or" );
EXPRESSION_TERMINATORS.add( ")" );
//expressionTerminators.add(","); // deliberately excluded
EXPRESSION_OPENERS.add( "and" );
EXPRESSION_OPENERS.add( "or" );
EXPRESSION_OPENERS.add( "(" );
//expressionOpeners.add(","); // deliberately excluded
BOOLEAN_OPERATORS.add( "<" );
BOOLEAN_OPERATORS.add( "=" );
BOOLEAN_OPERATORS.add( ">" );
BOOLEAN_OPERATORS.add( "#" );
BOOLEAN_OPERATORS.add( "~" );
BOOLEAN_OPERATORS.add( "like" );
BOOLEAN_OPERATORS.add( "ilike" );
BOOLEAN_OPERATORS.add( "regexp" );
BOOLEAN_OPERATORS.add( "rlike" );
BOOLEAN_OPERATORS.add( "is" );
BOOLEAN_OPERATORS.add( "in" );
BOOLEAN_OPERATORS.add( "any" );
BOOLEAN_OPERATORS.add( "some" );
BOOLEAN_OPERATORS.add( "all" );
BOOLEAN_OPERATORS.add( "exists" );
BOOLEAN_OPERATORS.add( "between" );
BOOLEAN_OPERATORS.add( "<=" );
BOOLEAN_OPERATORS.add( ">=" );
BOOLEAN_OPERATORS.add( "=>" );
BOOLEAN_OPERATORS.add( "=<" );
BOOLEAN_OPERATORS.add( "!=" );
BOOLEAN_OPERATORS.add( "<>" );
BOOLEAN_OPERATORS.add( "!#" );
BOOLEAN_OPERATORS.add( "!~" );
BOOLEAN_OPERATORS.add( "!<" );
BOOLEAN_OPERATORS.add( "!>" );
BOOLEAN_OPERATORS.add( "is not" );
BOOLEAN_OPERATORS.add( "not like" );
BOOLEAN_OPERATORS.add( "not ilike" );
BOOLEAN_OPERATORS.add( "not regexp" );
BOOLEAN_OPERATORS.add( "not rlike" );
BOOLEAN_OPERATORS.add( "not in" );
BOOLEAN_OPERATORS.add( "not between" );
BOOLEAN_OPERATORS.add( "not exists" );
NEGATIONS.put( "and", "or" );
NEGATIONS.put( "or", "and" );
NEGATIONS.put( "<", ">=" );
NEGATIONS.put( "=", "<>" );
NEGATIONS.put( ">", "<=" );
NEGATIONS.put( "#", "!#" );
NEGATIONS.put( "~", "!~" );
NEGATIONS.put( "like", "not like" );
NEGATIONS.put( "ilike", "not ilike" );
NEGATIONS.put( "regexp", "not regexp" );
NEGATIONS.put( "rlike", "not rlike" );
NEGATIONS.put( "is", "is not" );
NEGATIONS.put( "in", "not in" );
NEGATIONS.put( "exists", "not exists" );
NEGATIONS.put( "between", "not between" );
NEGATIONS.put( "<=", ">" );
NEGATIONS.put( ">=", "<" );
NEGATIONS.put( "=>", "<" );
NEGATIONS.put( "=<", ">" );
NEGATIONS.put( "!=", "=" );
NEGATIONS.put( "<>", "=" );
NEGATIONS.put( "!#", "#" );
NEGATIONS.put( "!~", "~" );
NEGATIONS.put( "!<", "<" );
NEGATIONS.put( "!>", ">" );
NEGATIONS.put( "is not", "is" );
NEGATIONS.put( "not like", "like" );
NEGATIONS.put( "not ilike", "ilike" );
NEGATIONS.put( "not regexp", "regexp" );
NEGATIONS.put( "not rlike", "rlike" );
NEGATIONS.put( "not in", "in" );
NEGATIONS.put( "not between", "between" );
NEGATIONS.put( "not exists", "exists" );
}
// Handles things like:
// a and b or c
// a and ( b or c )
// not a and not b
// not ( a and b )
// x between y and z (overloaded "and")
// x in ( a, b, c ) (overloaded brackets)
// not not a
// a is not null (overloaded "not")
// etc......
// and expressions like
// foo = bar (maps to: foo.id = bar.id)
// foo.Bar = 'foo' (maps to: foo.bar = 'foo')
// foo.Bar.Baz = 1.0 (maps to: foo.bar = bar.id and bar.baz = 1.0)
// 1.0 = foo.Bar.Baz (maps to: bar.baz = 1.0 and foo.Bar = bar.id)
// foo.Bar.Baz = a.B.C (maps to: bar.Baz = b.C and foo.Bar = bar.id and a.B = b.id)
// foo.Bar.Baz + a.B.C (maps to: bar.Baz + b.C and foo.Bar = bar.id and a.B = b.id)
// ( foo.Bar.Baz + 1.0 ) < 2.0 (maps to: ( bar.Baz + 1.0 ) < 2.0 and foo.Bar = bar.id)
private boolean betweenSpecialCase = false; //Inside a BETWEEN ... AND ... expression
private boolean negated = false;
private boolean inSubselect = false;
private int bracketsSinceSelect = 0;
private StringBuffer subselect;
private boolean expectingPathContinuation = false;
private int expectingIndex = 0;
// The following variables are stacks that keep information about each subexpression
// in the list of nested subexpressions we are currently processing.
private LinkedList nots = new LinkedList(); //were an odd or even number of NOTs encountered
private LinkedList joins = new LinkedList(); //the join string built up by compound paths inside this expression
private LinkedList booleanTests = new LinkedList(); //a flag indicating if the subexpression is known to be boolean
private String getElementName(PathExpressionParser.CollectionElement element, QueryTranslatorImpl q) throws QueryException {
String name;
if ( element.isOneToMany ) {
name = element.alias;
}
else {
Type type = element.elementType;
if ( type.isEntityType() ) { //ie. a many-to-many
String entityName = ( ( EntityType ) type ).getAssociatedEntityName();
name = pathExpressionParser.continueFromManyToMany( entityName, element.elementColumns, q );
}
else {
throw new QueryException( "illegally dereferenced collection element" );
}
}
return name;
}
public void token(String token, QueryTranslatorImpl q) throws QueryException {
String lcToken = token.toLowerCase();
//Cope with [,]
if ( token.equals( "[" ) && !expectingPathContinuation ) {
expectingPathContinuation = false;
if ( expectingIndex == 0 ) throw new QueryException( "unexpected [" );
return;
}
else if ( token.equals( "]" ) ) {
expectingIndex--;
expectingPathContinuation = true;
return;
}
//Cope with a continued path expression (ie. ].baz)
if ( expectingPathContinuation ) {
boolean pathExpressionContinuesFurther = continuePathExpression( token, q );
if ( pathExpressionContinuesFurther ) return; //NOTE: early return
}
//Cope with a subselect
if ( !inSubselect && ( lcToken.equals( "select" ) || lcToken.equals( "from" ) ) ) {
inSubselect = true;
subselect = new StringBuffer( 20 );
}
if ( inSubselect && token.equals( ")" ) ) {
bracketsSinceSelect--;
if ( bracketsSinceSelect == -1 ) {
QueryTranslatorImpl subq = new QueryTranslatorImpl(
subselect.toString(),
q.getEnabledFilters(),
q.getFactory()
);
try {
subq.compile( q );
}
catch ( MappingException me ) {
throw new QueryException( "MappingException occurred compiling subquery", me );
}
appendToken( q, subq.getSQLString() );
inSubselect = false;
bracketsSinceSelect = 0;
}
}
if ( inSubselect ) {
if ( token.equals( "(" ) ) bracketsSinceSelect++;
subselect.append( token ).append( ' ' );
return;
}
//Cope with special cases of AND, NOT, ()
specialCasesBefore( lcToken );
//Close extra brackets we opened
if ( !betweenSpecialCase && EXPRESSION_TERMINATORS.contains( lcToken ) ) {
closeExpression( q, lcToken );
}
//take note when this is a boolean expression
if ( BOOLEAN_OPERATORS.contains( lcToken ) ) {
booleanTests.removeLast();
booleanTests.addLast( Boolean.TRUE );
}
if ( lcToken.equals( "not" ) ) {
nots.addLast( new Boolean( !( ( Boolean ) nots.removeLast() ).booleanValue() ) );
negated = !negated;
return; //NOTE: early return
}
//process a token, mapping OO path expressions to SQL expressions
doToken( token, q );
//Open any extra brackets we might need.
if ( !betweenSpecialCase && EXPRESSION_OPENERS.contains( lcToken ) ) {
openExpression( q, lcToken );
}
//Cope with special cases of AND, NOT, )
specialCasesAfter( lcToken );
}
public void start(QueryTranslatorImpl q) throws QueryException {
token( "(", q );
}
public void end(QueryTranslatorImpl q) throws QueryException {
if ( expectingPathContinuation ) {
expectingPathContinuation = false;
PathExpressionParser.CollectionElement element = pathExpressionParser.lastCollectionElement();
if ( element.elementColumns.length != 1 ) throw new QueryException( "path expression ended in composite collection element" );
appendToken( q, element.elementColumns[0] );
addToCurrentJoin( element );
}
token( ")", q );
}
private void closeExpression(QueryTranslatorImpl q, String lcToken) {
if ( ( ( Boolean ) booleanTests.removeLast() ).booleanValue() ) { //it was a boolean expression
if ( booleanTests.size() > 0 ) {
// the next one up must also be
booleanTests.removeLast();
booleanTests.addLast( Boolean.TRUE );
}
// Add any joins
appendToken( q, ( joins.removeLast() ).toString() );
}
else {
StringBuffer join = ( StringBuffer ) joins.removeLast();
( ( StringBuffer ) joins.getLast() ).append( join.toString() );
}
if ( ( ( Boolean ) nots.removeLast() ).booleanValue() ) negated = !negated;
if ( !")".equals( lcToken ) ) appendToken( q, ")" );
}
private void openExpression(QueryTranslatorImpl q, String lcToken) {
nots.addLast( Boolean.FALSE );
booleanTests.addLast( Boolean.FALSE );
joins.addLast( new StringBuffer() );
if ( !"(".equals( lcToken ) ) appendToken( q, "(" );
}
private void preprocess(String token, QueryTranslatorImpl q) throws QueryException {
// ugly hack for cases like "elements(foo.bar.collection)"
// (multi-part path expression ending in elements or indices)
String[] tokens = StringHelper.split( ".", token, true );
if (
tokens.length > 5 &&
( CollectionPropertyNames.COLLECTION_ELEMENTS.equals( tokens[tokens.length - 1] )
|| CollectionPropertyNames.COLLECTION_INDICES.equals( tokens[tokens.length - 1] ) )
) {
pathExpressionParser.start( q );
for ( int i = 0; i < tokens.length - 3; i++ ) {
pathExpressionParser.token( tokens[i], q );
}
pathExpressionParser.token( null, q );
pathExpressionParser.end( q );
addJoin( pathExpressionParser.getWhereJoin(), q );
pathExpressionParser.ignoreInitialJoin();
}
}
private void doPathExpression(String token, QueryTranslatorImpl q) throws QueryException {
preprocess( token, q );
StringTokenizer tokens = new StringTokenizer( token, ".", true );
pathExpressionParser.start( q );
while ( tokens.hasMoreTokens() ) {
pathExpressionParser.token( tokens.nextToken(), q );
}
pathExpressionParser.end( q );
if ( pathExpressionParser.isCollectionValued() ) {
openExpression( q, "" );
appendToken( q, pathExpressionParser.getCollectionSubquery( q.getEnabledFilters() ) );
closeExpression( q, "" );
// this is ugly here, but needed because its a subquery
q.addQuerySpaces( q.getCollectionPersister( pathExpressionParser.getCollectionRole() ).getCollectionSpaces() );
}
else {
if ( pathExpressionParser.isExpectingCollectionIndex() ) {
expectingIndex++;
}
else {
addJoin( pathExpressionParser.getWhereJoin(), q );
appendToken( q, pathExpressionParser.getWhereColumn() );
}
}
}
private void addJoin(JoinSequence joinSequence, QueryTranslatorImpl q) throws QueryException {
//JoinFragment fromClause = q.createJoinFragment(true);
//fromClause.addJoins( join.toJoinFragment().toFromFragmentString(), StringHelper.EMPTY_STRING );
q.addFromJoinOnly( pathExpressionParser.getName(), joinSequence );
try {
addToCurrentJoin( joinSequence.toJoinFragment( q.getEnabledFilters(), true ).toWhereFragmentString() );
}
catch ( MappingException me ) {
throw new QueryException( me );
}
}
private void doToken(String token, QueryTranslatorImpl q) throws QueryException {
if ( q.isName( StringHelper.root( token ) ) ) { //path expression
doPathExpression( q.unalias( token ), q );
}
else if ( token.startsWith( ParserHelper.HQL_VARIABLE_PREFIX ) ) { //named query parameter
q.addNamedParameter( token.substring( 1 ) );
appendToken( q, "?" );
}
else {
Queryable persister = q.getEntityPersisterUsingImports( token );
if ( persister != null ) { // the name of a class
final String discrim = persister.getDiscriminatorSQLValue();
if ( InFragment.NULL.equals(discrim) || InFragment.NOT_NULL.equals(discrim) ) {
throw new QueryException( "subclass test not allowed for null or not null discriminator" );
}
else {
appendToken( q, discrim );
}
}
else {
Object constant;
if (
token.indexOf( '.' ) > -1 &&
( constant = ReflectHelper.getConstantValue( token ) ) != null
) {
Type type;
try {
type = TypeFactory.heuristicType( constant.getClass().getName() );
}
catch ( MappingException me ) {
throw new QueryException( me );
}
if ( type == null ) throw new QueryException( QueryTranslator.ERROR_CANNOT_DETERMINE_TYPE + token );
try {
appendToken( q, ( ( LiteralType ) type ).objectToSQLString( constant, q.getFactory().getDialect() ) );
}
catch ( Exception e ) {
throw new QueryException( QueryTranslator.ERROR_CANNOT_FORMAT_LITERAL + token, e );
}
}
else { //anything else
String negatedToken = negated ? ( String ) NEGATIONS.get( token.toLowerCase() ) : null;
if ( negatedToken != null && ( !betweenSpecialCase || !"or".equals( negatedToken ) ) ) {
appendToken( q, negatedToken );
}
else {
appendToken( q, token );
}
}
}
}
}
private void addToCurrentJoin(String sql) {
( ( StringBuffer ) joins.getLast() ).append( sql );
}
private void addToCurrentJoin(PathExpressionParser.CollectionElement ce)
throws QueryException {
try {
addToCurrentJoin( ce.joinSequence.toJoinFragment().toWhereFragmentString() + ce.indexValue.toString() );
}
catch ( MappingException me ) {
throw new QueryException( me );
}
}
private void specialCasesBefore(String lcToken) {
if ( lcToken.equals( "between" ) || lcToken.equals( "not between" ) ) {
betweenSpecialCase = true;
}
}
private void specialCasesAfter(String lcToken) {
if ( betweenSpecialCase && lcToken.equals( "and" ) ) {
betweenSpecialCase = false;
}
}
void appendToken(QueryTranslatorImpl q, String token) {
if ( expectingIndex > 0 ) {
pathExpressionParser.setLastCollectionElementIndexValue( token );
}
else {
q.appendWhereToken( token );
}
}
private boolean continuePathExpression(String token, QueryTranslatorImpl q) throws QueryException {
expectingPathContinuation = false;
PathExpressionParser.CollectionElement element = pathExpressionParser.lastCollectionElement();
if ( token.startsWith( "." ) ) { // the path expression continues after a ]
doPathExpression( getElementName( element, q ) + token, q ); // careful with this!
addToCurrentJoin( element );
return true; //NOTE: EARLY EXIT!
}
else { // the path expression ends at the ]
if ( element.elementColumns.length != 1 ) {
throw new QueryException( "path expression ended in composite collection element" );
}
appendToken( q, element.elementColumns[0] );
addToCurrentJoin( element );
return false;
}
}
}