Add back-off attribute to JMS namespace

 This commit adds a "back-off" attribute to the jms:listener-container
 element so that a BackOff instance can be provided for users of the
 XML namespace.

 Issue: SPR-11746

Author: snicoll

spring-jms/src/main/java/org/springframework/jms/config/JmsListenerContainerParser.java

@@ -54,6 +54,8 @@ class JmsListenerContainerParser extends AbstractListenerContainerParser {
 
 	private static final String RECOVERY_INTERVAL_ATTRIBUTE = "recovery-interval";
 
+	private static final String BACK_OFF_ATTRIBUTE = "back-off";
+
 
 	protected PropertyValues parseProperties(Element containerEle, ParserContext parserContext) {
 		final MutablePropertyValues properties = new MutablePropertyValues();
@@ -223,10 +225,18 @@ private PropertyValues parseContainerProperties(Element containerEle,
 			}
 		}
 
-		String recoveryInterval = containerEle.getAttribute(RECOVERY_INTERVAL_ATTRIBUTE);
-		if (StringUtils.hasText(recoveryInterval)) {
+		String backOffBeanName = containerEle.getAttribute(BACK_OFF_ATTRIBUTE);
+		if (StringUtils.hasText(backOffBeanName)) {
 			if (!isSimpleContainer) {
-				propertyValues.add("recoveryInterval", recoveryInterval);
+				propertyValues.add("backOff", new RuntimeBeanReference(backOffBeanName));
+			}
+		}
+		else { // No need to consider this if back-off is set
+			String recoveryInterval = containerEle.getAttribute(RECOVERY_INTERVAL_ATTRIBUTE);
+			if (StringUtils.hasText(recoveryInterval)) {
+				if (!isSimpleContainer) {
+					propertyValues.add("recoveryInterval", recoveryInterval);
+				}
 			}
 		}
 

spring-jms/src/main/java/org/springframework/jms/listener/DefaultMessageListenerContainer.java

@@ -224,16 +224,19 @@ public void setTaskExecutor(Executor taskExecutor) {
 	 * between recovery attempts. If the {@link BackOff} implementation
 	 * returns {@link BackOff#STOP}, this listener container will not further
 	 * attempt to recover.
+	 * <p>The {@link #setRecoveryInterval(long) recovery interval} is ignored
+	 * when this property is set.
 	 */
 	public void setBackOff(BackOff backOff) {
 		this.backOff = backOff;
 	}
 
 	/**
 	 * Specify the interval between recovery attempts, in <b>milliseconds</b>.
-	 * The default is 5000 ms, that is, 5 seconds.
-	 * <p>This is a convenience method to create a {@link FixedBackOff} with
-	 * the specified interval.
+	 * The default is 5000 ms, that is, 5 seconds. This is a convenience method
+	 * to create a {@link FixedBackOff} with the specified interval.
+	 * <p>For more recovery options, consider specifying a {@link BackOff}
+	 * instance instead.
 	 * @see #setBackOff(BackOff)
 	 * @see #handleListenerSetupFailure
 	 */

spring-jms/src/main/resources/org/springframework/jms/config/spring-jms-4.1.xsd

@@ -318,11 +318,29 @@
 					]]></xsd:documentation>
 				</xsd:annotation>
 			</xsd:attribute>
+			<xsd:attribute name="back-off" type="xsd:string">
+				<xsd:annotation>
+					<xsd:documentation><![CDATA[
+	 Specify the BackOff instance to use to compute the interval between recovery
+	 attempts. If the BackOff implementation returns "BackOff#STOP", the listener
+	 container will not further attempt to recover. The recovery-interval value is
+	 ignored when this property is set. The default is a FixedBackOff with an
+	 interval of 5000 ms, that is 5 seconds.
+					]]></xsd:documentation>
+					<xsd:appinfo>
+						<tool:annotation kind="ref">
+							<tool:expected-type type="org.springframework.util.BackOff"/>
+						</tool:annotation>
+					</xsd:appinfo>
+				</xsd:annotation>
+			</xsd:attribute>
 			<xsd:attribute name="recovery-interval" type="xsd:string">
 				<xsd:annotation>
 					<xsd:documentation><![CDATA[
-	Specify the interval between recovery attempts, in milliseconds.
-	The default is 5000 ms, that is, 5 seconds.
+	Specify the interval between recovery attempts, in milliseconds. Convenience
+	way to create a FixedBackOff with the specified interval. For more recovery
+	options, consider specifying a BackOff instance instead. The default is
+	5000 ms, that is 5 seconds.
 					]]></xsd:documentation>
 				</xsd:annotation>
 			</xsd:attribute>

spring-jms/src/test/java/org/springframework/jms/config/JmsNamespaceHandlerTests.java

@@ -161,6 +161,7 @@ public void testJmsContainerFactoryConfiguration() {
 		assertEquals("wrong concurrency", 3, container.getConcurrentConsumers());
 		assertEquals("wrong concurrency", 5, container.getMaxConcurrentConsumers());
 		assertEquals("wrong prefetch", 50, container.getMaxMessagesPerTask());
+		assertSame(context.getBean("testBackOff"),new DirectFieldAccessor(container).getPropertyValue("backOff"));
 
 		assertEquals("phase cannot be customized by the factory", Integer.MAX_VALUE, container.getPhase());
 	}
@@ -216,12 +217,13 @@ public void testListeners() throws Exception {
 
 	@Test
 	public void testRecoveryInterval() {
-		long recoveryInterval1 = getRecoveryInterval("listener1");
-		long recoveryInterval2 = getRecoveryInterval("listener2");
+		Object testBackOff = context.getBean("testBackOff");
+		BackOff backOff1 = getBackOff("listener1");
+		BackOff backOff2 = getBackOff("listener2");
 		long recoveryInterval3 = getRecoveryInterval(DefaultMessageListenerContainer.class.getName() + "#0");
 
-		assertEquals(1000L, recoveryInterval1);
-		assertEquals(1000L, recoveryInterval2);
+		assertSame(testBackOff, backOff1);
+		assertSame(testBackOff, backOff2);
 		assertEquals(DefaultMessageListenerContainer.DEFAULT_RECOVERY_INTERVAL, recoveryInterval3);
 	}
 
@@ -300,9 +302,13 @@ private ErrorHandler getErrorHandler(String containerBeanName) {
 		return (ErrorHandler) new DirectFieldAccessor(container).getPropertyValue("errorHandler");
 	}
 
-	private long getRecoveryInterval(String containerBeanName) {
+	private BackOff getBackOff(String containerBeanName) {
 		DefaultMessageListenerContainer container = this.context.getBean(containerBeanName, DefaultMessageListenerContainer.class);
-		BackOff backOff = (BackOff) new DirectFieldAccessor(container).getPropertyValue("backOff");
+		return (BackOff) new DirectFieldAccessor(container).getPropertyValue("backOff");
+	}
+
+	private long getRecoveryInterval(String containerBeanName) {
+		BackOff backOff = getBackOff(containerBeanName);
 		assertEquals(FixedBackOff.class, backOff.getClass());
 		return ((FixedBackOff)backOff).getInterval();
 	}

spring-jms/src/test/resources/org/springframework/jms/config/jmsNamespaceHandlerTests.xml

@@ -9,7 +9,7 @@
 			connection-factory="testConnectionFactory" task-executor="testTaskExecutor"
 			destination-resolver="testDestinationResolver" message-converter="testMessageConverter"
 			transaction-manager="testTransactionManager" error-handler="testErrorHandler"
-			cache="connection" concurrency="3-5" prefetch="50" receive-timeout="100" recovery-interval="1000" phase="99">
+			cache="connection" concurrency="3-5" prefetch="50" receive-timeout="100" back-off="testBackOff" phase="99">
 		<jms:listener id="listener1" destination="testDestination" ref="testBean1" method="setName"/>
 		<jms:listener id="listener2" destination="testDestination" ref="testBean2" method="setName" response-destination="responseDestination"/>
 	</jms:listener-container>
@@ -43,7 +43,8 @@
 							connection-factory="testConnectionFactory" task-executor="testTaskExecutor"
 							destination-resolver="testDestinationResolver" message-converter="testMessageConverter"
 							transaction-manager="testTransactionManager" error-handler="testErrorHandler"
-							concurrency="3-5" prefetch="50" receive-timeout="100" recovery-interval="1000"/>
+							concurrency="3-5" prefetch="50" receive-timeout="100"
+							recovery-interval="1000" back-off="testBackOff"/>
 
 	<!-- the default ConnectionFactory -->
 	<bean id="connectionFactory" class="org.springframework.jms.StubConnectionFactory"/>
@@ -67,6 +68,10 @@
 
 	<bean id="testErrorHandler" class="org.springframework.jms.config.JmsNamespaceHandlerTests$TestErrorHandler"/>
 
+	<bean id="testBackOff" class="org.springframework.util.FixedBackOff">
+		<property name="interval" value="1000"/>
+	</bean>
+
 	<bean id="testBean1" class="org.springframework.tests.sample.beans.TestBean"/>
 
 	<bean id="testBean2" class="org.springframework.tests.sample.beans.TestBean"/>

src/asciidoc/index.adoc

@@ -40424,6 +40424,10 @@ This listener container strikes a good balance between low requirements on the J
 provider, advanced functionality such as transaction participation, and compatibility
 with Java EE environments.
 
+This container also has recoverable capabilities when the broker goes down. By default,
+a simple `BackOff` implementation retries every 5 seconds. It is possible to specify
+a custom `BackOff` implementation for more fine-grained recovery options, see
+`ExponentialBackOff` for an example.
 
 
 [[jms-tx]]
@@ -41427,9 +41431,18 @@ choices and message redelivery scenarios.
 | The timeout to use for receive calls (in milliseconds). The default is `1000` ms (1
   sec); `-1` indicates no timeout at all.
 
+| back-off
+| Specify the `BackOff` instance to use to compute the interval between recovery
+  attempts. If the `BackOff` implementation returns `BackOff#STOP`, the listener
+  container will not further attempt to recover. The `recovery-interval value is
+  is ignored when this property is set. The default is a `FixedBackOff` with an
+  interval of 5000 ms, that is 5 seconds.
+
 | recovery-interval
-| Specify the interval between recovery attempts, in milliseconds. The default is `5000`
-  ms, that is, 5 seconds.
+| Specify the interval between recovery attempts, in milliseconds. Convenience
+  way to create a `FixedBackOff` with the specified interval. For more recovery
+  options, consider specifying a BackOff instance instead. The default is 5000 ms,
+  that is 5 seconds.
 
 | phase
 | The lifecycle phase within which this container should start and stop. The lower the