001// Copyright 2010 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.annotations; 016 017import static java.lang.annotation.RetentionPolicy.RUNTIME; 018import static org.apache.tapestry5.ioc.annotations.AnnotationUseContext.COMPONENT; 019import static org.apache.tapestry5.ioc.annotations.AnnotationUseContext.MIXIN; 020import static org.apache.tapestry5.ioc.annotations.AnnotationUseContext.PAGE; 021 022import java.lang.annotation.Documented; 023import java.lang.annotation.ElementType; 024import java.lang.annotation.Retention; 025import java.lang.annotation.Target; 026 027import org.apache.tapestry5.internal.transform.HeartbeatDeferredWorker; 028import org.apache.tapestry5.ioc.annotations.UseWith; 029import org.apache.tapestry5.services.Heartbeat; 030 031/** 032 * Marks a component method as deferred until the end of the {@link Heartbeat}. This 033 * is only allowed on void methods that do not throw exceptions. The invocation is captured 034 * and will execute at the end of the current Heartbeat. 035 * <p> 036 * This annotation should be used with care, since deferring the invocation can change its semantics. For example, the 037 * value stored in instance variables may change between the time the method is invoked and the time it eventually 038 * executes. Likewise, runtime exceptions thrown by the method can not be caught by the invoking method. 039 * <p> 040 * Annotated methods must return void, and not declare any checked exceptions. 041 * 042 * @since 5.2.0 043 * @see HeartbeatDeferredWorker 044 */ 045@Target(ElementType.METHOD) 046@Retention(RUNTIME) 047@Documented 048@UseWith( 049{ COMPONENT, MIXIN, PAGE }) 050public @interface HeartbeatDeferred 051{ 052 053}