// Copyright (c) 1998-2008 Adrian Kuhn <akuhn(a)students.unibe.ch>
//
// This file is part of ch.akuhn.util.
//
// ch.akuhn.util is free software: you can redistribute it and/or modify it
// under the terms of the GNU Lesser General Public License as published by the
// Free Software Foundation, either version 3 of the License, or (at your
// option) any later version.
//
// ch.akuhn.util is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
// License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with ch.akuhn.util. If not, see <http://www.gnu.org/licenses/>.
//
package ch.akuhn.util;
import java.lang.reflect.Constructor;
/**
* ACME = a factory making everything.
*
* @author akuhn
*
*/
public class Factory<T> {
@SuppressWarnings("unchecked")
private static final <T> Constructor<T> searchConstructor(Constructor<?>[] all, int parameterLength) {
Constructor result = null;
for (Constructor init : all) {
if (init.getParameterTypes().length == parameterLength) {
if (result != null) throw new AssertionError("Ambigous constructor");
result = init;
}
}
return (Constructor<T>) result;
}
private Constructor<T> takeOne;
private Constructor<T> takeThree;
private Constructor<T> takeTwo;
private Class<T> type;
public Factory(Class<T> type) {
this.type = type;
Constructor<?>[] all = type.getDeclaredConstructors();
this.takeOne = searchConstructor(all, 1);
this.takeTwo = searchConstructor(all, 2);
this.takeThree = searchConstructor(all, 3);
}
public T create() {
try {
return type.newInstance();
} catch (Exception ex) {
throw new RuntimeException(ex);
}
}
public T create(Object obj) {
try {
return takeOne.newInstance(obj);
} catch (Exception ex) {
throw Throw.exception(ex);
}
}
public T create(Object obj1, Object obj2) {
try {
return takeTwo.newInstance(obj1, obj2);
} catch (Exception ex) {
throw Throw.exception(ex);
}
}
public T create(Object obj1, Object obj2, Object obj3) {
try {
return takeThree.newInstance(obj1, obj2, obj3);
} catch (Exception ex) {
throw Throw.exception(ex);
}
}
}