/* Copyright 2005-2006 Tim Fennell
*
* 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 net.sourceforge.stripes.util.bean;
import java.lang.reflect.Array;
/**
* Implementation of the {@link PropertyAccessor} interface for interacting with arrays.
* Throws exceptions if the index is not an integer or if the index is out of range
* for the current array.
*
* @author Tim Fennell
* @since Stripes 1.4
*/
public class ArrayPropertyAccessor implements PropertyAccessor<Object>{
/**
* Gets the index specified by the current node from the target array.
* @param evaluation the current NodeEvaluation containing the array index
* @param target the target array
* @return the element stored at that index
*/
public Object getValue(NodeEvaluation evaluation, Object target) {
int index = getKey(evaluation);
return Array.get(target, index);
}
/**
* Sets the value at the index specified by the current node to the supplied value.
* @param evaluation the current NodeEvaluation containing the array index
* @param target the target array
* @param value the value to set, possibly null
*/
public void setValue(NodeEvaluation evaluation, Object target, Object value) {
int index = getKey(evaluation);
Array.set(target, index, value);
}
/**
* Fetches the key and casts/unboxes it to an int. If the key is not an int, it
* will throw an Evaluation Exception.
*/
private int getKey(NodeEvaluation eval) {
Object key = eval.getNode().getTypedValue();
if (key.getClass() != Integer.class) {
throw new EvaluationException
("Attempting to index into an array using a non-integer index: " + key);
}
return (Integer) key;
}
}