/*
* Copyright 2015, The Querydsl Team (http://www.querydsl.com/team)
*
* Licensed 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 com.querydsl.core.types;
import javax.annotation.Nullable;
/**
* {@code ExpressionBase} is the base class for immutable {@link Expression} implementations
*
* @author tiwe
*
* @param <T> expression type
*/
public abstract class ExpressionBase<T> implements Expression<T> {
private static final long serialVersionUID = -8862014178653364345L;
private final Class<? extends T> type;
@Nullable
private transient volatile String toString;
@Nullable
private transient volatile Integer hashCode;
public ExpressionBase(Class<? extends T> type) {
this.type = type;
}
@Override
public final Class<? extends T> getType() {
return type;
}
@Override
public final int hashCode() {
if (hashCode == null) {
hashCode = accept(HashCodeVisitor.DEFAULT, null);
}
return hashCode;
}
@Override
public final String toString() {
if (toString == null) {
toString = accept(ToStringVisitor.DEFAULT, Templates.DEFAULT);
}
return toString;
}
}