Java tutorial
/* Copyright 2010 Abhinav Sarkar <abhinav@abhinavsarkar.net> * * This file is a part of SpelHelper library. * * SpelHelper library is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License (GNU LGPL) as * published by the Free Software Foundation, either version 3 of the License, * or (at your option) any later version. * * SpelHelper library 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 SpelHelper library. If not, see <http://www.gnu.org/licenses/>. */ package net.abhinavsarkar.spelhelper; import java.lang.reflect.Constructor; import java.util.List; import org.springframework.core.convert.TypeDescriptor; import org.springframework.expression.AccessException; import org.springframework.expression.ConstructorExecutor; import org.springframework.expression.ConstructorResolver; import org.springframework.expression.EvaluationContext; import org.springframework.expression.spel.support.ReflectiveConstructorResolver; final class ImplicitConstructorResolver implements ConstructorResolver { private final ReflectiveConstructorResolver delegate = new ReflectiveConstructorResolver(); @Override public ConstructorExecutor resolve(final EvaluationContext context, final String typeName, final List<TypeDescriptor> argumentTypes) throws AccessException { try { return delegate.resolve(context, typeName, argumentTypes); } catch (AccessException ex) { Object variable = ((SpelHelper) context.lookupVariable(SpelHelper.CONTEXT_LOOKUP_KEY)) .lookupImplicitConstructor(typeName + argumentTypes.toString()); if (variable instanceof Constructor<?>) { Constructor<?> constructor = (Constructor<?>) variable; return delegate.resolve(context, constructor.getDeclaringClass().getName(), argumentTypes); } return null; } } }