/*
* 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.loader.custom.sql;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.hibernate.QueryException;
import org.hibernate.engine.query.ParameterParser;
import org.hibernate.persister.collection.SQLLoadableCollection;
import org.hibernate.persister.entity.SQLLoadable;
/**
* @author Gavin King
* @author Max Andersen
* @author Steve Ebersole
*/
public class SQLQueryParser {
private final String originalQueryString;
private final ParserContext context;
private final Map namedParameters = new HashMap();
private long aliasesFound = 0;
static interface ParserContext {
boolean isEntityAlias(String aliasName);
SQLLoadable getEntityPersisterByAlias(String alias);
String getEntitySuffixByAlias(String alias);
boolean isCollectionAlias(String aliasName);
SQLLoadableCollection getCollectionPersisterByAlias(String alias);
String getCollectionSuffixByAlias(String alias);
Map getPropertyResultsMapByAlias(String alias);
}
public SQLQueryParser(String queryString, ParserContext context) {
this.originalQueryString = queryString;
this.context = context;
}
public Map getNamedParameters() {
return namedParameters;
}
public boolean queryHasAliases() {
return aliasesFound>0;
}
public String process() {
return substituteParams( substituteBrackets( originalQueryString ) );
}
// TODO: should "record" how many properties we have reffered to - and if we
// don't get'em'all we throw an exception! Way better than trial and error ;)
private String substituteBrackets(String sqlQuery) throws QueryException {
StringBuffer result = new StringBuffer( sqlQuery.length() + 20 );
int left, right;
// replace {....} with corresponding column aliases
for ( int curr = 0; curr < sqlQuery.length(); curr = right + 1 ) {
if ( ( left = sqlQuery.indexOf( '{', curr ) ) < 0 ) {
// No additional open braces found in the string, append the
// rest of the string in its entirty and quit this loop
result.append( sqlQuery.substring( curr ) );
break;
}
// apend everything up until the next encountered open brace
result.append( sqlQuery.substring( curr, left ) );
if ( ( right = sqlQuery.indexOf( '}', left + 1 ) ) < 0 ) {
throw new QueryException( "Unmatched braces for alias path", sqlQuery );
}
String aliasPath = sqlQuery.substring( left + 1, right );
int firstDot = aliasPath.indexOf( '.' );
if ( firstDot == -1 ) {
if ( context.isEntityAlias( aliasPath ) ) {
// it is a simple table alias {foo}
result.append( aliasPath );
aliasesFound++;
}
else {
// passing through anything we do not know : to support jdbc escape sequences HB-898
result.append( '{' ).append(aliasPath).append( '}' );
}
}
else {
String aliasName = aliasPath.substring(0, firstDot);
boolean isCollection = context.isCollectionAlias( aliasName );
boolean isEntity = context.isEntityAlias( aliasName );
if ( isCollection ) {
// The current alias is referencing the collection to be eagerly fetched
String propertyName = aliasPath.substring( firstDot + 1 );
result.append( resolveCollectionProperties( aliasName, propertyName ) );
aliasesFound++;
}
else if ( isEntity ) {
// it is a property reference {foo.bar}
String propertyName = aliasPath.substring( firstDot + 1 );
result.append( resolveProperties( aliasName, propertyName ) );
aliasesFound++;
}
else {
// passing through anything we do not know : to support jdbc escape sequences HB-898
result.append( '{' ).append(aliasPath).append( '}' );
}
}
}
// Possibly handle :something parameters for the query ?
return result.toString();
}
private String resolveCollectionProperties(
String aliasName,
String propertyName) {
Map fieldResults = context.getPropertyResultsMapByAlias( aliasName );
SQLLoadableCollection collectionPersister = context.getCollectionPersisterByAlias( aliasName );
String collectionSuffix = context.getCollectionSuffixByAlias( aliasName );
if ( "*".equals( propertyName ) ) {
if( !fieldResults.isEmpty() ) {
throw new QueryException("Using return-propertys together with * syntax is not supported.");
}
String selectFragment = collectionPersister.selectFragment( aliasName, collectionSuffix );
aliasesFound++;
return selectFragment
+ ", "
+ resolveProperties( aliasName, propertyName );
}
else if ( "element.*".equals( propertyName ) ) {
return resolveProperties( aliasName, "*" );
}
else {
String[] columnAliases;
// Let return-propertys override whatever the persister has for aliases.
columnAliases = ( String[] ) fieldResults.get(propertyName);
if ( columnAliases==null ) {
columnAliases = collectionPersister.getCollectionPropertyColumnAliases( propertyName, collectionSuffix );
}
if ( columnAliases == null || columnAliases.length == 0 ) {
throw new QueryException(
"No column name found for property [" + propertyName + "] for alias [" + aliasName + "]",
originalQueryString
);
}
if ( columnAliases.length != 1 ) {
// TODO: better error message since we actually support composites if names are explicitly listed.
throw new QueryException(
"SQL queries only support properties mapped to a single column - property [" +
propertyName + "] is mapped to " + columnAliases.length + " columns.",
originalQueryString
);
}
aliasesFound++;
return columnAliases[0];
}
}
private String resolveProperties(
String aliasName,
String propertyName) {
Map fieldResults = context.getPropertyResultsMapByAlias( aliasName );
SQLLoadable persister = context.getEntityPersisterByAlias( aliasName );
String suffix = context.getEntitySuffixByAlias( aliasName );
if ( "*".equals( propertyName ) ) {
if( !fieldResults.isEmpty() ) {
throw new QueryException("Using return-propertys together with * syntax is not supported.");
}
aliasesFound++;
return persister.selectFragment( aliasName, suffix ) ;
}
else {
String[] columnAliases;
// Let return-propertys override whatever the persister has for aliases.
columnAliases = (String[]) fieldResults.get( propertyName );
if ( columnAliases == null ) {
columnAliases = persister.getSubclassPropertyColumnAliases( propertyName, suffix );
}
if ( columnAliases == null || columnAliases.length == 0 ) {
throw new QueryException(
"No column name found for property [" + propertyName + "] for alias [" + aliasName + "]",
originalQueryString
);
}
if ( columnAliases.length != 1 ) {
// TODO: better error message since we actually support composites if names are explicitly listed.
throw new QueryException(
"SQL queries only support properties mapped to a single column - property [" + propertyName + "] is mapped to " + columnAliases.length + " columns.",
originalQueryString
);
}
aliasesFound++;
return columnAliases[0];
}
}
/**
* Substitues JDBC parameter placeholders (?) for all encountered
* parameter specifications. It also tracks the positions of these
* parameter specifications within the query string. This accounts for
* ordinal-params, named-params, and ejb3-positional-params.
*
* @param sqlString The query string.
* @return The SQL query with parameter substitution complete.
*/
private String substituteParams(String sqlString) {
ParameterSubstitutionRecognizer recognizer = new ParameterSubstitutionRecognizer();
ParameterParser.parse( sqlString, recognizer );
namedParameters.clear();
namedParameters.putAll( recognizer.namedParameterBindPoints );
return recognizer.result.toString();
}
public static class ParameterSubstitutionRecognizer implements ParameterParser.Recognizer {
StringBuffer result = new StringBuffer();
Map namedParameterBindPoints = new HashMap();
int parameterCount = 0;
public void outParameter(int position) {
result.append( '?' );
}
public void ordinalParameter(int position) {
result.append( '?' );
}
public void namedParameter(String name, int position) {
addNamedParameter( name );
result.append( '?' );
}
public void jpaPositionalParameter(String name, int position) {
namedParameter( name, position );
}
public void other(char character) {
result.append( character );
}
private void addNamedParameter(String name) {
Integer loc = new Integer( parameterCount++ );
Object o = namedParameterBindPoints.get( name );
if ( o == null ) {
namedParameterBindPoints.put( name, loc );
}
else if ( o instanceof Integer ) {
ArrayList list = new ArrayList( 4 );
list.add( o );
list.add( loc );
namedParameterBindPoints.put( name, list );
}
else {
( ( List ) o ).add( loc );
}
}
}
}