001    package groovy.sql;
002    
003    import java.util.ArrayList;
004    import java.util.List;
005    
006    import org.codehaus.groovy.ast.CodeVisitorSupport;
007    import org.codehaus.groovy.ast.expr.BinaryExpression;
008    import org.codehaus.groovy.ast.expr.BooleanExpression;
009    import org.codehaus.groovy.ast.expr.ConstantExpression;
010    import org.codehaus.groovy.ast.expr.Expression;
011    import org.codehaus.groovy.ast.expr.PropertyExpression;
012    import org.codehaus.groovy.ast.stmt.ReturnStatement;
013    import org.codehaus.groovy.syntax.Token;
014    import org.codehaus.groovy.syntax.Types;
015    
016    /**
017     * @author James Strachan
018     * @version $Revision: 1.2 $
019     */
020    public class SqlWhereVisitor extends CodeVisitorSupport {
021    
022        private StringBuffer buffer = new StringBuffer();
023        private List parameters = new ArrayList();
024    
025        public String getWhere() {
026            return buffer.toString();
027        }
028    
029        public void visitReturnStatement(ReturnStatement statement) {
030            statement.getExpression().visit(this);
031        }
032    
033        public void visitBinaryExpression(BinaryExpression expression) {
034            Expression left = expression.getLeftExpression();
035            Expression right = expression.getRightExpression();
036    
037            left.visit(this);
038            buffer.append(" ");
039    
040            Token token = expression.getOperation();
041            buffer.append(tokenAsSql(token));
042    
043            buffer.append(" ");
044            right.visit(this);
045        }
046    
047        public void visitBooleanExpression(BooleanExpression expression) {
048            expression.getExpression().visit(this);
049        }
050    
051        public void visitConstantExpression(ConstantExpression expression) {
052            getParameters().add(expression.getValue());
053            buffer.append("?");
054        }
055    
056        public void visitPropertyExpression(PropertyExpression expression) {
057            buffer.append(expression.getProperty());
058        }
059        
060        public List getParameters() {
061            return parameters;
062        }
063        
064        protected String tokenAsSql(Token token) {
065            switch (token.getType()) {
066                case Types.COMPARE_EQUAL :
067                    return "=";
068                case Types.LOGICAL_AND :
069                    return "and";
070                case Types.LOGICAL_OR :
071                    return "or";
072                default :
073                    return token.getText();
074            }
075        }
076    }