org.apache.openjpa.kernel.exps.ValExpression Maven / Gradle / Ivy
/*
* 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.apache.openjpa.kernel.exps;
import java.util.Collection;
import org.apache.openjpa.kernel.StoreContext;
/**
* Boolean value used as an expression.
*
* @author Abe White
*/
class ValExpression
extends Exp {
private static final long serialVersionUID = 1L;
private final Val _val;
/**
* Constructor. Supply value.
*/
public ValExpression(Val val) {
_val = val;
}
@Override
protected boolean eval(Object candidate, Object orig,
StoreContext ctx, Object[] params) {
Object o = _val.eval(candidate, orig, ctx, params);
return o != null && (Boolean) o;
}
@Override
protected boolean eval(Collection candidates, StoreContext ctx,
Object[] params) {
Collection c = _val.eval(candidates, null, ctx, params);
Object o = (c == null || c.isEmpty()) ? null : c.iterator().next();
return o != null && (Boolean) o;
}
@Override
public void acceptVisit(ExpressionVisitor visitor) {
visitor.enter(this);
_val.acceptVisit(visitor);
visitor.exit(this);
}
}