BATCH-1396: added step scope to completion policy in chunk parser

spring-batch-core-tests/src/main/resources/META-INF/batch/footballJob.xml

@@ -11,7 +11,7 @@
 		<step id="playerload" next="gameLoad">
 			<tasklet>
 				<chunk reader="playerFileItemReader" writer="playerWriter" 
-	                   commit-interval="${job.commit.interval}" />
+	                   commit-interval="#{jobParameters['commit.interval']}" />
 			</tasklet>
 		</step>
 		<step id="gameLoad" next="playerSummarization">

spring-batch-core-tests/src/test/java/org/springframework/batch/core/test/football/FootballJobIntegrationTests.java

@@ -37,10 +37,9 @@ import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 import org.springframework.test.jdbc.SimpleJdbcTestUtils;
 
-
 /**
  * @author Dave Syer
- *
+ * 
  */
 @RunWith(SpringJUnit4ClassRunner.class)
 @ContextConfiguration(locations = { "/simple-job-launcher-context.xml", "/META-INF/batch/footballJob.xml" })
@@ -48,31 +47,32 @@ public class FootballJobIntegrationTests {
 
 	/** Logger */
 	private final Log logger = LogFactory.getLog(getClass());
-	
+
 	private SimpleJdbcTemplate simpleJdbcTemplate;
 
 	@Autowired
 	private JobLauncher jobLauncher;
-	
+
 	@Autowired
 	private Job job;
-	
+
 	@Autowired
 	public void setDataSource(DataSource dataSource) {
 		this.simpleJdbcTemplate = new SimpleJdbcTemplate(dataSource);
 	}
-	
+
 	@Before
 	public void clear() {
 		SimpleJdbcTestUtils.deleteFromTables(simpleJdbcTemplate, "PLAYER_SUMMARY", "GAMES", "PLAYERS");
 	}
-	
+
 	@Test
 	public void testLaunchJob() throws Exception {
-		JobExecution execution = jobLauncher.run(job, new JobParametersBuilder().toJobParameters());
+		JobExecution execution = jobLauncher.run(job, new JobParametersBuilder().addLong("commit.interval", 10L)
+				.toJobParameters());
 		assertEquals(BatchStatus.COMPLETED, execution.getStatus());
 		for (StepExecution stepExecution : execution.getStepExecutions()) {
-			logger.info("Processed: "+stepExecution);
+			logger.info("Processed: " + stepExecution);
 		}
 	}
 

spring-batch-core/src/main/java/org/springframework/batch/core/configuration/xml/ChunkElementParser.java

@@ -18,6 +18,7 @@ package org.springframework.batch.core.configuration.xml;
 import java.util.List;
 
 import org.springframework.batch.core.listener.StepListenerMetaData;
+import org.springframework.batch.repeat.policy.SimpleCompletionPolicy;
 import org.springframework.beans.MutablePropertyValues;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.BeanDefinitionHolder;
@@ -25,6 +26,7 @@ import org.springframework.beans.factory.config.RuntimeBeanReference;
 import org.springframework.beans.factory.config.TypedStringValue;
 import org.springframework.beans.factory.parsing.CompositeComponentDefinition;
 import org.springframework.beans.factory.support.AbstractBeanDefinition;
+import org.springframework.beans.factory.support.BeanDefinitionBuilder;
 import org.springframework.beans.factory.support.GenericBeanDefinition;
 import org.springframework.beans.factory.support.ManagedList;
 import org.springframework.beans.factory.support.ManagedMap;
@@ -59,7 +61,8 @@ public class ChunkElementParser {
 
 	private static final String ITEM_WRITER_ADAPTER_CLASS = "org.springframework.batch.item.adapter.ItemWriterAdapter";
 
-	private static final StepListenerParser stepListenerParser = new StepListenerParser(StepListenerMetaData.itemListenerMetaData());
+	private static final StepListenerParser stepListenerParser = new StepListenerParser(
+			StepListenerMetaData.itemListenerMetaData());
 
 	/**
 	 * @param element
@@ -80,7 +83,17 @@ public class ChunkElementParser {
 
 		String commitInterval = element.getAttribute(COMMIT_INTERVAL_ATTR);
 		if (StringUtils.hasText(commitInterval)) {
-			propertyValues.addPropertyValue("commitInterval", commitInterval);
+			if (commitInterval.startsWith("#")) {
+				// It's a late binding expression, so we need step scope...
+				BeanDefinitionBuilder completionPolicy = BeanDefinitionBuilder
+						.genericBeanDefinition(SimpleCompletionPolicy.class);
+				completionPolicy.addConstructorArgValue(commitInterval);
+				completionPolicy.setScope("step");
+				propertyValues.addPropertyValue("chunkCompletionPolicy", completionPolicy.getBeanDefinition());
+			}
+			else {
+				propertyValues.addPropertyValue("commitInterval", commitInterval);
+			}
 		}
 
 		String completionPolicyRef = element.getAttribute(CHUNK_COMPLETION_POLICY_ATTR);
@@ -144,7 +157,7 @@ public class ChunkElementParser {
 		handleRetryListenersElement(element, propertyValues, parserContext, bd);
 
 		handleStreamsElement(element, propertyValues, parserContext);
-		
+
 		stepListenerParser.handleListenersElement(element, bd, parserContext);
 
 	}
@@ -202,8 +215,8 @@ public class ChunkElementParser {
 			propertyValues.addPropertyValue(propertyName, beanDefinitionHolder);
 		}
 		else if (refElements.size() == 1) {
-			propertyValues.addPropertyValue(propertyName, parserContext.getDelegate().parsePropertySubElement(
-					refElements.get(0), null));
+			propertyValues.addPropertyValue(propertyName,
+					parserContext.getDelegate().parsePropertySubElement(refElements.get(0), null));
 		}
 
 		handleAdapterMethodAttribute(propertyName, adapterClassName, propertyValues, element);
@@ -251,7 +264,8 @@ public class ChunkElementParser {
 	}
 
 	@SuppressWarnings("unchecked")
-	private void handleRetryListenerElements(ParserContext parserContext, Element element, ManagedList beans, BeanDefinition enclosing) {
+	private void handleRetryListenerElements(ParserContext parserContext, Element element, ManagedList beans,
+			BeanDefinition enclosing) {
 		List<Element> listenerElements = DomUtils.getChildElementsByTagName(element, "listener");
 		if (listenerElements != null) {
 			for (Element listenerElement : listenerElements) {

spring-batch-core/src/main/java/org/springframework/batch/core/resource/StepExecutionSimpleCompletionPolicy.java

@@ -27,12 +27,21 @@ import org.springframework.batch.repeat.policy.SimpleCompletionPolicy;
 import org.springframework.util.Assert;
 
 /**
+ * <p>
  * A {@link CompletionPolicy} that picks up a commit interval from
  * {@link JobParameters} by listening to the start of a step. Use anywhere that
  * a {@link CompletionPolicy} can be used (usually at the chunk level in a
  * step), and inject as a {@link StepExecutionListener} into the surrounding
  * step. N.B. only after the step has started will the completion policy be
  * usable.
+ * </p>
+ * 
+ * <p>
+ * It is easier and probably preferable to simply declare the chunk with a
+ * commit-interval that is a late-binding expression (e.g.
+ * <code>#{jobParameters['commit.interval']}</code>). That feature is available
+ * from of Spring Batch 2.1.7.
+ * </p>
  * 
  * @author Dave Syer
  * 

spring-batch-core/src/main/resources/org/springframework/batch/core/configuration/xml/spring-batch-2.1.xsd

@@ -823,7 +823,8 @@ ref"							is not required, and only needs to be specified explicitly
 			<xsd:annotation>
 				<xsd:documentation><![CDATA[
 				The number of items that will be processed before commit is called for the transaction.  
-				Either set this or the chunk-completion-policy but not both.
+				Either set this or the chunk-completion-policy but not both.  Can be specified as an expression
+				that will be evaluated in the scope of the step (e.g. "#{jobParameters['commit.interval']}").
 				]]></xsd:documentation>
 			</xsd:annotation>
 		</xsd:attribute>

spring-batch-core/src/test/java/org/springframework/batch/core/configuration/xml/ChunkElementParserTests.java

@@ -65,6 +65,14 @@ public class ChunkElementParserTests {
 		assertTrue("Wrong processor type", chunkProcessor instanceof SimpleChunkProcessor);
 	}
 
+	@Test
+	public void testCommitIntervalLateBinding() throws Exception {
+		ConfigurableApplicationContext context = new ClassPathXmlApplicationContext(
+				"org/springframework/batch/core/configuration/xml/ChunkElementCommitIntervalParserTests-context.xml");
+		Step step = (Step) context.getBean("s1", Step.class);
+		assertNotNull("Step not parsed", step);
+	}
+
 	@Test
 	public void testRetryPolicyAttribute() throws Exception {
 		ConfigurableApplicationContext context = new ClassPathXmlApplicationContext(