/*
* Copyright 2016 Nabarun Mondal
* 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 com.noga.njexl.lang.internal;
import java.lang.reflect.InvocationTargetException;
/**
* Specialized executor to set a property of an object.
* <p>Duck as in duck-typing for an interface like:
* <code>
* interface Set {
* Object set(Object property, Object value);
* }
* </code>
* </p>
* @since 2.0
*/
public final class DuckSetExecutor extends AbstractExecutor.Set {
/** The property. */
private final Object property;
/**
* Creates an instance.
*@param is the introspector
*@param clazz the class to find the set method from
*@param key the key to use as 1st argument to the set method
*@param value the value to use as 2nd argument to the set method
*/
public DuckSetExecutor(Introspector is, Class<?> clazz, Object key, Object value) {
super(clazz, discover(is, clazz, key, value));
property = key;
}
/** {@inheritDoc} */
@Override
public Object getTargetProperty() {
return property;
}
/** {@inheritDoc} */
@Override
public Object execute(Object obj, Object value)
throws IllegalAccessException, InvocationTargetException {
Object[] pargs = {property, value};
if (method != null) {
method.invoke(obj, pargs);
}
return value;
}
/** {@inheritDoc} */
@Override
public Object tryExecute(Object obj, Object key, Object value) {
if (obj != null && method != null
// ensure method name matches the property name
&& property.equals(key)
&& objectClass.equals(obj.getClass())) {
try {
Object[] args = {property, value};
method.invoke(obj, args);
return value;
} catch (InvocationTargetException xinvoke) {
return TRY_FAILED; // fail
} catch (IllegalAccessException xill) {
return TRY_FAILED;// fail
}
}
return TRY_FAILED;
}
/**
* Discovers the method for a {@link DuckSet}.
*@param is the introspector
*@param clazz the class to find the set method from
*@param key the key to use as 1st argument to the set method
*@param value the value to use as 2nd argument to the set method
*@return the method if found, null otherwise
*/
private static java.lang.reflect.Method discover(Introspector is,
Class<?> clazz, Object key, Object value) {
return is.getMethod(clazz, "set", makeArgs(key, value));
}
}