// $Id: AbstractRestrictableStatement.java 7460 2005-07-12 20:27:29Z steveebersole $
package org.hibernate.hql.ast.tree;
import org.hibernate.hql.antlr.HqlSqlTokenTypes;
import org.hibernate.hql.ast.util.ASTUtil;
import antlr.collections.AST;
import org.apache.commons.logging.Log;
/**
* Convenience implementation of RestrictableStatement to centralize common functionality.
*
* @author Steve Ebersole
*/
public abstract class AbstractRestrictableStatement extends AbstractStatement implements RestrictableStatement {
private FromClause fromClause;
private AST whereClause;
protected abstract int getWhereClauseParentTokenType();
protected abstract Log getLog();
/**
* @see org.hibernate.hql.ast.tree.RestrictableStatement#getFromClause
*/
public final FromClause getFromClause() {
if ( fromClause == null ) {
fromClause = ( FromClause ) ASTUtil.findTypeInChildren( this, HqlSqlTokenTypes.FROM );
}
return fromClause;
}
/**
* @see RestrictableStatement#hasWhereClause
*/
public final boolean hasWhereClause() {
AST whereClause = locateWhereClause();
return whereClause != null && whereClause.getNumberOfChildren() > 0;
}
/**
* @see org.hibernate.hql.ast.tree.RestrictableStatement#getWhereClause
*/
public final AST getWhereClause() {
if ( whereClause == null ) {
whereClause = locateWhereClause();
// If there is no WHERE node, make one.
if ( whereClause == null ) {
getLog().debug( "getWhereClause() : Creating a new WHERE clause..." );
whereClause = ASTUtil.create( getWalker().getASTFactory(), HqlSqlTokenTypes.WHERE, "WHERE" );
// inject the WHERE after the parent
AST parent = ASTUtil.findTypeInChildren( this, getWhereClauseParentTokenType() );
whereClause.setNextSibling( parent.getNextSibling() );
parent.setNextSibling( whereClause );
}
}
return whereClause;
}
protected AST locateWhereClause() {
return ASTUtil.findTypeInChildren( this, HqlSqlTokenTypes.WHERE );
}
}
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