| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.ofbiz.sql; |
| |
| public abstract class Value extends Atom { |
| public static final class Null extends Value { |
| private Null() { |
| } |
| @Override |
| public void accept(Visitor visitor) { |
| visitor.visit(this); |
| } |
| |
| public StringBuilder appendTo(StringBuilder sb) { |
| return sb.append("NULL"); |
| } |
| } |
| |
| public static final Null NULL = new Null(); |
| |
| public interface Visitor { |
| void visit(AggregateFunction value); |
| void visit(FieldValue value); |
| void visit(FunctionCall value); |
| void visit(MathValue value); |
| void visit(Null value); |
| void visit(NumberValue<?> value); |
| void visit(ParameterValue value); |
| void visit(StringValue value); |
| void visit(CountAllFunction value); |
| } |
| |
| public static class BaseVisitor implements Visitor { |
| public void visit(AggregateFunction value) { |
| } |
| |
| public void visit(FieldValue value) { |
| } |
| |
| public void visit(FunctionCall value) { |
| } |
| |
| public void visit(MathValue value) { |
| } |
| |
| public void visit(Null value) { |
| } |
| |
| public void visit(NumberValue<?> value) { |
| } |
| |
| public void visit(ParameterValue value) { |
| } |
| |
| public void visit(StringValue value) { |
| } |
| |
| public void visit(CountAllFunction value) { |
| } |
| } |
| |
| public abstract void accept(Visitor visitor); |
| } |