    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
    015    package org.apache.tapestry5.services;
    016
    017    import java.lang.annotation.Documented;
    018    import static java.lang.annotation.ElementType.FIELD;
    019    import static java.lang.annotation.ElementType.PARAMETER;
    020    import java.lang.annotation.Retention;
    021    import static java.lang.annotation.RetentionPolicy.RUNTIME;
    022    import java.lang.annotation.Target;
    023
    024    /**
    025     * Marker annotation used to identify a service from the component layer that conflicts, in terms of service interface,
    026     * with a service from elsewhere. In particular, this is used to disambiguate {@link
    027     * org.apache.tapestry5.ioc.services.ClassFactory} 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
    034    public @interface ComponentLayer
    035    {
    036
    037    }