001// Copyright 2006, 2007, 2008, 2009 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.ioc.annotations; 016 017import org.apache.tapestry5.ioc.ServiceBinder; 018import org.apache.tapestry5.ioc.ServiceLifecycle; 019import org.apache.tapestry5.ioc.services.ServiceLifecycleSource; 020 021import java.lang.annotation.Documented; 022import static java.lang.annotation.ElementType.METHOD; 023import static java.lang.annotation.ElementType.TYPE; 024import java.lang.annotation.Retention; 025import static java.lang.annotation.RetentionPolicy.RUNTIME; 026import java.lang.annotation.Target; 027 028/** 029 * An optional annotation that may be placed on a service building method of a module, or on the implementation class 030 * (when using service binding). The annotation overrides the default scope for services (the default being a global 031 * singleton that is instantiated on demand) for an alternate lifecycle. Alternate lifecycles are typically used to bind 032 * a service implementation to a single thread or request. Modules may define new scopes. Each scope should have a 033 * corresponding {@link ServiceLifecycle} implementation. The linkage from scope name to service lifecycle occurs via a 034 * contribution to the {@link ServiceLifecycleSource} service configuration. 035 * <p/> 036 * The annotation may also be placed directly on a service implementation class, when using service binding (via 037 * the {@link ServiceBinder}). 038 * 039 * @see org.apache.tapestry5.ioc.ScopeConstants 040 */ 041@Target( 042 {TYPE, METHOD}) 043@Retention(RUNTIME) 044@Documented 045@UseWith({AnnotationUseContext.SERVICE, AnnotationUseContext.MODULE}) 046public @interface Scope 047{ 048 /** 049 * An identifier used to look up a non-default {@link ServiceLifecycle}. 050 */ 051 String value(); 052}