001 // Copyright 2011 The Apache Software Foundation 002 // 003 // Licensed under the Apache License, Version 2.0 (the "License"); 004 // you may not use this file except in compliance with the License. 005 // You may obtain a copy of the License at 006 // 007 // http://www.apache.org/licenses/LICENSE-2.0 008 // 009 // Unless required by applicable law or agreed to in writing, software 010 // distributed under the License is distributed on an "AS IS" BASIS, 011 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012 // See the License for the specific language governing permissions and 013 // limitations under the License. 014 015 package org.apache.tapestry5.ioc.internal; 016 017 import org.apache.tapestry5.ioc.ObjectLocator; 018 import org.apache.tapestry5.ioc.services.TypeCoercer; 019 020 /** 021 * A proxy for the {@link TypeCoercer} 022 * 023 * @since 5.3 024 */ 025 public final class TypeCoercerProxyImpl implements TypeCoercerProxy 026 { 027 private final ObjectLocator locator; 028 029 private TypeCoercer delegate; 030 031 public TypeCoercerProxyImpl(ObjectLocator locator) 032 { 033 this.locator = locator; 034 } 035 036 private TypeCoercer delegate() 037 { 038 if (delegate == null) 039 delegate = locator.getService(TypeCoercer.class); 040 041 return delegate; 042 } 043 044 public <S, T> T coerce(S input, Class<T> targetType) 045 { 046 if (targetType.isInstance(input)) 047 return targetType.cast(input); 048 049 return delegate().coerce(input, targetType); 050 } 051 052 }