org.apache.openjpa.kernel.exps.Coalesce Maven / Gradle / Ivy
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* 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 org.apache.openjpa.kernel.Filters;
import org.apache.openjpa.kernel.StoreContext;
/**
* An in-memory representation of a coalesce expression
*
* @author Catalina Wei
*/
public class Coalesce
extends Val {
private final Val[] _val;
/**
* Constructor.
*/
Coalesce(Val[] val) {
_val = val;
}
@Override
protected Object eval(Object candidate, Object orig, StoreContext ctx,
Object[] params) {
for (int i = 0; i < _val.length-1; i++) {
Object o1 = _val[i].eval(candidate, orig, ctx, params);
if (o1 != null)
return o1;
else
continue;
}
return _val[_val.length-1].eval(candidate, orig, ctx, params);
}
protected Object eval(Object candidate, StoreContext ctx,
Object[] params) {
for (int i = 0; i < _val.length-1; i++) {
Object o1 = _val[i].eval(candidate, null, ctx, params);
if (o1 != null)
return o1;
else
continue;
}
return _val[_val.length-1].eval(candidate, null, ctx, params);
}
/**
* Compare the two values.
*/
protected boolean compare(Object o1, Object o2) {
return (o1 == null && o2 == null)
|| (o1 != null && o1.equals(o2));
}
public Val[] getVal() {
return _val;
}
public Class getType() {
Class c1 = _val[0].getType();
for (int i = 1; i < _val.length; i++) {
Class c2 = _val[i].getType();
c1 = Filters.promote(c1, c2);
}
return c1;
}
public void setImplicitType(Class type) {
}
public void acceptVisit(ExpressionVisitor visitor) {
visitor.enter(this);
for (int i = 0; i < _val.length; i++)
_val[i].acceptVisit(visitor);
visitor.exit(this);
}
}