javaa.beans.UtilListPersistenceDelegate 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 javaa.beans;
import javaa.beans.DefaultPersistenceDelegate;
import javaa.beans.Encoder;
import javaa.beans.Expression;
import javaa.beans.PersistenceDelegate;
import javaa.beans.Statement;
import java.util.List;
class UtilListPersistenceDelegate extends DefaultPersistenceDelegate {
@Override
@SuppressWarnings({ "nls", "boxing" })
protected void initialize(Class type, Object oldInstance,
Object newInstance, Encoder enc) {
List list = (List) oldInstance;
int size = list.size();
for (int i = 0; i < size; i++) {
Expression getterExp = new Expression(oldInstance, "get",
new Object[] { i });
try {
// Calculate the old value of the property
Object oldVal = getterExp.getValue();
// Write the getter expression to the encoder
enc.writeExpression(getterExp);
// Get the target value that exists in the new environment
Object targetVal = enc.get(oldVal);
// Get the current property value in the new environment
Object newVal = null;
try {
newVal = new Expression(newInstance, "get",
new Object[] { i }).getValue();
} catch (IndexOutOfBoundsException ex) {
// The newInstance has no elements, so current property
// value remains null
}
/*
* Make the target value and current property value equivalent
* in the new environment
*/
if (null == targetVal) {
if (null != newVal) {
// Set to null
Statement setterStm = new Statement(oldInstance, "add",
new Object[] { null });
enc.writeStatement(setterStm);
}
} else {
PersistenceDelegate pd = enc
.getPersistenceDelegate(targetVal.getClass());
if (!pd.mutatesTo(targetVal, newVal)) {
Statement setterStm = new Statement(oldInstance, "add",
new Object[] { oldVal });
enc.writeStatement(setterStm);
}
}
} catch (Exception ex) {
enc.getExceptionListener().exceptionThrown(ex);
}
}
}
}