001// Copyright 2007 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
015package org.apache.tapestry5.services;
016
017import java.lang.annotation.Documented;
018import java.lang.annotation.Retention;
019import java.lang.annotation.Target;
020
021import static java.lang.annotation.ElementType.FIELD;
022import static java.lang.annotation.ElementType.PARAMETER;
023import static java.lang.annotation.RetentionPolicy.RUNTIME;
024
025/**
026 * Marker annotation used to identify a service from the component layer that conflicts, in terms of service interface,
027 * with a service from elsewhere. In particular, this is used to disambiguate {@link org.apache.tapestry5.ioc.services.PlasticProxyFactory} which has one implementation (marked with {@link
028 * org.apache.tapestry5.ioc.services.Builtin} and another with this annotation.
029 */
030@Target(
031        {PARAMETER, FIELD})
032@Retention(RUNTIME)
033@Documented
034public @interface ComponentLayer
035{
036
037}