SPR-8205 added support for a 'trigger' attribute (bean ref) on scheduled-task elements

org.springframework.context/src/main/java/org/springframework/scheduling/config/ScheduledTasksBeanDefinitionParser.java

 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2011 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -53,6 +53,7 @@ public class ScheduledTasksBeanDefinitionParser extends AbstractSingleBeanDefini
 		ManagedMap<RuntimeBeanReference, String> cronTaskMap = new ManagedMap<RuntimeBeanReference, String>();
 		ManagedMap<RuntimeBeanReference, String> fixedDelayTaskMap = new ManagedMap<RuntimeBeanReference, String>();
 		ManagedMap<RuntimeBeanReference, String> fixedRateTaskMap = new ManagedMap<RuntimeBeanReference, String>();
+		ManagedMap<RuntimeBeanReference, RuntimeBeanReference> triggerTaskMap = new ManagedMap<RuntimeBeanReference, RuntimeBeanReference>();
 		NodeList childNodes = element.getChildNodes();
 		for (int i = 0; i < childNodes.getLength(); i++) {
 			Node child = childNodes.item(i);
@@ -72,25 +73,35 @@ public class ScheduledTasksBeanDefinitionParser extends AbstractSingleBeanDefini
 			
 			RuntimeBeanReference runnableBeanRef = new RuntimeBeanReference(
 					createRunnableBean(ref, method, taskElement, parserContext));
+
 			String cronAttribute = taskElement.getAttribute("cron");
-			if (StringUtils.hasText(cronAttribute)) {
+			String fixedDelayAttribute = taskElement.getAttribute("fixed-delay");
+			String fixedRateAttribute = taskElement.getAttribute("fixed-rate");
+			String triggerAttribute = taskElement.getAttribute("trigger");
+
+			boolean hasCronAttribute = StringUtils.hasText(cronAttribute);
+			boolean hasFixedDelayAttribute = StringUtils.hasText(fixedDelayAttribute);
+			boolean hasFixedRateAttribute = StringUtils.hasText(fixedRateAttribute);
+			boolean hasTriggerAttribute = StringUtils.hasText(triggerAttribute);
+
+			if (!(hasCronAttribute | hasFixedDelayAttribute | hasFixedRateAttribute | hasTriggerAttribute)) {
+				parserContext.getReaderContext().error(
+						"exactly one of the 'cron', 'fixed-delay', 'fixed-rate', or 'trigger' attributes is required", taskElement);
+				// Continue with the possible next task element
+				continue;
+			}
+
+			if (hasCronAttribute) {
 				cronTaskMap.put(runnableBeanRef, cronAttribute);
 			}
-			else {
-				String fixedDelayAttribute = taskElement.getAttribute("fixed-delay");
-				if (StringUtils.hasText(fixedDelayAttribute)) {
-					fixedDelayTaskMap.put(runnableBeanRef, fixedDelayAttribute);
-				}
-				else {
-					String fixedRateAttribute = taskElement.getAttribute("fixed-rate");
-					if (!StringUtils.hasText(fixedRateAttribute)) {
-						parserContext.getReaderContext().error(
-								"One of 'cron', 'fixed-delay', or 'fixed-rate' is required", taskElement);
-						// Continue with the possible next task element
-						continue;
-					}
-					fixedRateTaskMap.put(runnableBeanRef, fixedRateAttribute);
-				}
+			if (hasFixedDelayAttribute) {
+				fixedDelayTaskMap.put(runnableBeanRef, fixedDelayAttribute);
+			}
+			if (hasFixedRateAttribute) {
+				fixedRateTaskMap.put(runnableBeanRef, fixedRateAttribute);
+			}
+			if (hasTriggerAttribute) {
+				triggerTaskMap.put(runnableBeanRef, new RuntimeBeanReference(triggerAttribute));
 			}
 		}
 		String schedulerRef = element.getAttribute("scheduler");
@@ -100,6 +111,7 @@ public class ScheduledTasksBeanDefinitionParser extends AbstractSingleBeanDefini
 		builder.addPropertyValue("cronTasks", cronTaskMap);
 		builder.addPropertyValue("fixedDelayTasks", fixedDelayTaskMap);
 		builder.addPropertyValue("fixedRateTasks", fixedRateTaskMap);
+		builder.addPropertyValue("triggerTasks", triggerTaskMap);
 	}
 
 	private boolean isScheduledElement(Node node, ParserContext parserContext) {

org.springframework.context/src/main/resources/org/springframework/scheduling/config/spring-task-3.1.xsd

@@ -216,6 +216,13 @@
 				]]></xsd:documentation>
 			</xsd:annotation>
 		</xsd:attribute>
+		<xsd:attribute name="trigger" type="xsd:string" use="optional">
+			<xsd:annotation>
+				<xsd:documentation><![CDATA[
+	A reference to a bean that implements the Trigger interface.
+ 				]]></xsd:documentation>
+			</xsd:annotation>
+		</xsd:attribute>
 		<xsd:attribute name="ref" type="xsd:string" use="required">
 			<xsd:annotation>
 				<xsd:documentation><![CDATA[

org.springframework.context/src/test/java/org/springframework/scheduling/config/ScheduledTasksBeanDefinitionParserTests.java

@@ -18,6 +18,7 @@ package org.springframework.scheduling.config;
 
 import java.lang.reflect.Method;
 import java.util.Collection;
+import java.util.Date;
 import java.util.Map;
 
 import static org.junit.Assert.*;
@@ -27,6 +28,8 @@ import org.junit.Test;
 import org.springframework.beans.DirectFieldAccessor;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.support.ClassPathXmlApplicationContext;
+import org.springframework.scheduling.Trigger;
+import org.springframework.scheduling.TriggerContext;
 import org.springframework.scheduling.support.ScheduledMethodRunnable;
 
 /**
@@ -98,12 +101,28 @@ public class ScheduledTasksBeanDefinitionParserTests {
 		assertEquals("*/4 * 9-17 * * MON-FRI", expression);		
 	}
 
+	@Test
+	public void triggerTasks() {
+		Map<Runnable, Trigger> tasks = (Map<Runnable, Trigger>) new DirectFieldAccessor(
+				this.registrar).getPropertyValue("triggerTasks");
+		assertEquals(1, tasks.size());
+		Trigger trigger = tasks.values().iterator().next();
+		assertEquals(TestTrigger.class, trigger.getClass());		
+	}
+
 
 	static class TestBean {
 
 		public void test() {
 		}
+	}
+
 
+	static class TestTrigger implements Trigger {
+
+		public Date nextExecutionTime(TriggerContext triggerContext) {
+			return null;
+		}
 	}
 
 }

org.springframework.context/src/test/resources/org/springframework/scheduling/config/scheduledTasksContext.xml

@@ -12,10 +12,13 @@
 		<task:scheduled ref="testBean" method="test" fixed-rate="2000"/>
 		<task:scheduled ref="testBean" method="test" fixed-delay="3000"/>
 		<task:scheduled ref="testBean" method="test" cron="*/4 * 9-17 * * MON-FRI"/>
+		<task:scheduled ref="testBean" method="test" trigger="customTrigger"/>
 	</task:scheduled-tasks>
 
 	<task:scheduler id="testScheduler"/>
 
 	<bean id="testBean" class="org.springframework.scheduling.config.ScheduledTasksBeanDefinitionParserTests$TestBean"/>
 
+	<bean id="customTrigger" class="org.springframework.scheduling.config.ScheduledTasksBeanDefinitionParserTests$TestTrigger"/>
+
 </beans>