/
OptionalNullGetter.java
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/
OptionalNullGetter.java
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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.commons.jexl3.jexl342;
import org.apache.commons.jexl3.JexlEngine;
import org.apache.commons.jexl3.JexlException;
import org.apache.commons.jexl3.introspection.JexlPropertyGet;
import org.apache.commons.jexl3.introspection.JexlUberspect;
import java.util.Objects;
/**
* JexlPropertyGet on a reference that pointed null.
* <p>Performs a late discovery of the actual getter.</p>
*/
public class OptionalNullGetter implements JexlPropertyGet {
/** The Uberspect to discover the getter. */
private final JexlUberspect uberspect;
/** The property we are trying to discover. */
private final Object property;
/** The result when we solve it. */
private JexlPropertyGet delegate;
OptionalNullGetter(JexlUberspect jexlUberspect, Object key) {
uberspect = jexlUberspect;
property = key;
}
@Override
public Object invoke(Object obj) throws Exception {
if (obj == null) {
return null;
}
if (delegate == null) {
delegate = uberspect.getPropertyGet(obj, property);
if (delegate == null) {
throw new JexlException.Property(null, Objects.toString(property), false, null);
}
}
return delegate.invoke(obj);
}
@Override
public Object tryInvoke(Object obj, Object key) throws JexlException.TryFailed {
if (obj == null) {
return null;
}
return delegate != null ? delegate.tryInvoke(obj, property) : JexlEngine.TRY_FAILED;
}
@Override
public boolean tryFailed(Object rval) {
return delegate != null ? delegate.tryFailed(rval) : JexlEngine.TRY_FAILED == rval;
}
@Override
public boolean isCacheable() {
return false;
}
}