RESOLVED - issue BATCH-398: That old stateful / stateless thing again....

http://jira.springframework.org/browse/BATCH-398

Fix JMX demo using an application context per job execution.

spring-batch-core/src/main/java/org/springframework/batch/core/repository/JobRegistry.java

@@ -29,18 +29,18 @@ public interface JobRegistry extends JobLocator {
 	/**
 	 * Registers a {@link Job} at runtime.
 	 * 
-	 * @param job the {@link Job} to be registered
+	 * @param jobFactory the {@link Job} to be registered
 	 * 
-	 * @throws DuplicateJobException if a configuration with the
-	 * same name has already been registered.
+	 * @throws DuplicateJobException if a factory with the same job name has
+	 * already been registered.
 	 */
-	void register(Job job) throws DuplicateJobException;
+	void register(JobFactory jobFactory) throws DuplicateJobException;
 
 	/**
-	 * Unregisters a previously registered {@link Job}. If it was
-	 * not previously registered there is no error.
+	 * Unregisters a previously registered {@link Job}. If it was not
+	 * previously registered there is no error.
 	 * 
-	 * @param job the {@link Job} to unregister.
+	 * @param jobName the {@link Job} to unregister.
 	 */
-	void unregister(Job job);
+	void unregister(String jobName);
 }

spring-batch-execution/src/main/java/org/springframework/batch/execution/configuration/JobRegistryBeanPostProcessor.java

@@ -45,7 +45,7 @@ public class JobRegistryBeanPostProcessor implements BeanPostProcessor, Initiali
 	// It doesn't make sense for this to have a default value...
 	private JobRegistry jobConfigurationRegistry = null;
 
-	private Collection jobConfigurations = new HashSet();
+	private Collection jobNames = new HashSet();
 
 	/**
 	 * Injection setter for {@link JobRegistry}.
@@ -71,11 +71,11 @@ public class JobRegistryBeanPostProcessor implements BeanPostProcessor, Initiali
 	 * @see org.springframework.beans.factory.DisposableBean#destroy()
 	 */
 	public void destroy() throws Exception {
-		for (Iterator iter = jobConfigurations.iterator(); iter.hasNext();) {
-			Job jobConfiguration = (Job) iter.next();
-			jobConfigurationRegistry.unregister(jobConfiguration);
+		for (Iterator iter = jobNames.iterator(); iter.hasNext();) {
+			String name = (String) iter.next();
+			jobConfigurationRegistry.unregister(name);
 		}
-		jobConfigurations.clear();
+		jobNames.clear();
 	}
 
 	/**
@@ -88,10 +88,10 @@ public class JobRegistryBeanPostProcessor implements BeanPostProcessor, Initiali
 	 */
 	public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
 		if (bean instanceof Job) {
-			Job jobConfiguration = (Job) bean;
+			Job job = (Job) bean;
 			try {
-				jobConfigurationRegistry.register(jobConfiguration);
-				jobConfigurations.add(jobConfiguration);
+				jobConfigurationRegistry.register(new ReferenceJobFactory(job));
+				jobNames.add(job.getName());
 			}
 			catch (DuplicateJobException e) {
 				throw new FatalBeanException("Cannot register job configuration", e);

spring-batch-execution/src/main/java/org/springframework/batch/execution/configuration/MapJobRegistry.java

@@ -23,14 +23,15 @@ import java.util.Map;
 
 import org.springframework.batch.core.domain.Job;
 import org.springframework.batch.core.repository.DuplicateJobException;
+import org.springframework.batch.core.repository.JobFactory;
 import org.springframework.batch.core.repository.JobRegistry;
 import org.springframework.batch.core.repository.ListableJobRegistry;
 import org.springframework.batch.core.repository.NoSuchJobException;
 import org.springframework.util.Assert;
 
 /**
- * Simple map-based implementation of {@link JobRegistry}. Access
- * to the map is synchronized, guarded by an internal lock.
+ * Simple map-based implementation of {@link JobRegistry}. Access to the map is
+ * synchronized, guarded by an internal lock.
  * 
  * @author Dave Syer
  * 
@@ -43,17 +44,16 @@ public class MapJobRegistry implements ListableJobRegistry {
 	 * (non-Javadoc)
 	 * @see org.springframework.batch.container.common.configuration.JobConfigurationRegistry#registerJobConfiguration(org.springframework.batch.container.common.configuration.JobConfiguration)
 	 */
-	public void register(Job jobConfiguration) throws DuplicateJobException {
-		Assert.notNull(jobConfiguration);
-		String name = jobConfiguration.getName();
+	public void register(JobFactory jobFactory) throws DuplicateJobException {
+		Assert.notNull(jobFactory);
+		String name = jobFactory.getJobName();
 		Assert.notNull(name, "Job configuration must have a name.");
 		synchronized (map) {
-			if (map.containsKey(name) && jobConfiguration.equals(map.get(name))) {
+			if (map.containsKey(name)) {
 				throw new DuplicateJobException("A job configuration with this name [" + name
 						+ "] was already registered");
 			}
-			// allow replacing job configuration with new instance
-			map.put(name, jobConfiguration);
+			map.put(name, jobFactory);
 		}
 	}
 
@@ -61,8 +61,7 @@ public class MapJobRegistry implements ListableJobRegistry {
 	 * (non-Javadoc)
 	 * @see org.springframework.batch.container.common.configuration.JobConfigurationRegistry#unregister(org.springframework.batch.container.common.configuration.JobConfiguration)
 	 */
-	public void unregister(Job jobConfiguration) {
-		String name = jobConfiguration.getName();
+	public void unregister(String name) {
 		Assert.notNull(name, "Job configuration must have a name.");
 		synchronized (map) {
 			map.remove(name);
@@ -77,15 +76,14 @@ public class MapJobRegistry implements ListableJobRegistry {
 	public Job getJob(String name) throws NoSuchJobException {
 		synchronized (map) {
 			if (!map.containsKey(name)) {
-				throw new NoSuchJobException("No job configuration with the name [" + name
-						+ "] was registered");
+				throw new NoSuchJobException("No job configuration with the name [" + name + "] was registered");
 			}
-			return (Job) map.get(name);
+			return (Job) ((JobFactory) map.get(name)).createJob();
 		}
 	}
 
-
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.batch.container.common.configuration.ListableJobConfigurationRegistry#getJobConfigurations()
 	 */
 	public Collection getJobNames() {

spring-batch-execution/src/main/java/org/springframework/batch/execution/configuration/ReferenceJobFactory.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2006-2007 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.batch.execution.configuration;
+
+import org.springframework.batch.core.domain.Job;
+import org.springframework.batch.core.repository.JobFactory;
+
+/**
+ * A {@link JobFactory} that just keeps a reference to a {@link Job}. It never
+ * modifies its {@link Job}.
+ * 
+ * @author Dave Syer
+ * 
+ */
+public class ReferenceJobFactory implements JobFactory {
+
+	private Job job;
+
+	private String name;
+
+	/**
+	 * @param job the {@link Job} to return from {@link #createJob()}.
+	 */
+	public ReferenceJobFactory(Job job) {
+		super();
+		this.job = job;
+		this.name = job.getName();
+	}
+
+	/**
+	 * Just return the instance passed in on initialization.
+	 * 
+	 * @see org.springframework.batch.core.repository.JobFactory#createJob()
+	 */
+	public Job createJob() {
+		return job;
+	}
+
+	/**
+	 * Returns the job name as passed in on initialization.
+	 * 
+	 * @see org.springframework.batch.core.repository.JobFactory#getJobName()
+	 */
+	public String getJobName() {
+		return name;
+	}
+
+}

spring-batch-execution/src/test/java/org/springframework/batch/execution/bootstrap/support/SimpleExportedJobLauncherTests.java

@@ -29,6 +29,7 @@ import org.springframework.batch.core.domain.StepExecution;
 import org.springframework.batch.core.repository.JobExecutionAlreadyRunningException;
 import org.springframework.batch.core.runtime.JobParametersFactory;
 import org.springframework.batch.execution.configuration.MapJobRegistry;
+import org.springframework.batch.execution.configuration.ReferenceJobFactory;
 import org.springframework.batch.execution.job.JobSupport;
 import org.springframework.batch.execution.launch.JobLauncher;
 import org.springframework.batch.execution.step.StepSupport;
@@ -117,7 +118,7 @@ public class SimpleExportedJobLauncherTests extends TestCase {
 	 * @throws Exception
 	 */
 	public void testGetStatisticsWithContent() throws Exception {
-		jobLocator.register(new JobSupport("foo"));
+		jobLocator.register(new ReferenceJobFactory(new JobSupport("foo")));
 		launcher.run("foo");
 		Properties props = launcher.getStatistics();
 		assertNotNull(props);
@@ -130,7 +131,7 @@ public class SimpleExportedJobLauncherTests extends TestCase {
 	 * @throws Exception
 	 */
 	public void testIsRunning() throws Exception {
-		jobLocator.register(new JobSupport("foo"));
+		jobLocator.register(new ReferenceJobFactory(new JobSupport("foo")));
 		launcher.run("foo");
 		assertTrue(launcher.isRunning());
 	}
@@ -141,7 +142,7 @@ public class SimpleExportedJobLauncherTests extends TestCase {
 	 * @throws Exception
 	 */
 	public void testAlreadyRunning() throws Exception {
-		jobLocator.register(new JobSupport("foo"));
+		jobLocator.register(new ReferenceJobFactory(new JobSupport("foo")));
 		launcher.setLauncher(new JobLauncher() {
 			public JobExecution run(Job job, JobParameters jobParameters) throws JobExecutionAlreadyRunningException {
 				throw new JobExecutionAlreadyRunningException("Bad!");
@@ -166,7 +167,7 @@ public class SimpleExportedJobLauncherTests extends TestCase {
 	 * @throws Exception 
 	 */
 	public void testRunJobWithParameters() throws Exception {
-		jobLocator.register(new JobSupport("foo"));
+		jobLocator.register(new ReferenceJobFactory(new JobSupport("foo")));
 		String value = launcher.run("foo", "bar=spam,bucket=crap");
 		assertTrue(launcher.isRunning());
 		assertTrue("Return value was not a JobExecution: " + value, value.contains("JobExecution"));
@@ -178,7 +179,7 @@ public class SimpleExportedJobLauncherTests extends TestCase {
 	 * @throws Exception 
 	 */
 	public void testRunJobWithParametersAndFactory() throws Exception {
-		jobLocator.register(new JobSupport("foo"));
+		jobLocator.register(new ReferenceJobFactory(new JobSupport("foo")));
 		launcher.setJobParametersFactory(new JobParametersFactory() {
 			public JobParameters getJobParameters(Properties properties) {
 				return new JobParametersBuilder().addString("foo", "spam").toJobParameters();
@@ -198,7 +199,7 @@ public class SimpleExportedJobLauncherTests extends TestCase {
 	 * @throws Exception 
 	 */
 	public void testStop() throws Exception {
-		jobLocator.register(new JobSupport("foo"));
+		jobLocator.register(new ReferenceJobFactory(new JobSupport("foo")));
 		launcher.run("foo");
 		assertTrue(launcher.isRunning());
 		launcher.stop();

spring-batch-execution/src/test/java/org/springframework/batch/execution/configuration/MapJobRegistryTests.java

@@ -19,10 +19,9 @@ import java.util.Collection;
 
 import junit.framework.TestCase;
 
-import org.springframework.batch.core.domain.Job;
 import org.springframework.batch.core.repository.DuplicateJobException;
+import org.springframework.batch.core.repository.JobFactory;
 import org.springframework.batch.core.repository.NoSuchJobException;
-import org.springframework.batch.execution.configuration.MapJobRegistry;
 import org.springframework.batch.execution.job.JobSupport;
 
 /**
@@ -34,13 +33,13 @@ public class MapJobRegistryTests extends TestCase {
 	private MapJobRegistry registry = new MapJobRegistry();
 
 	/**
-	 * Test method for {@link org.springframework.batch.execution.configuration.MapJobRegistry#unregister(org.springframework.batch.execution.job.JobSupport)}.
+	 * Test method for {@link org.springframework.batch.execution.configuration.MapJobRegistry#unregister(String)}.
 	 * @throws Exception 
 	 */
 	public void testUnregister() throws Exception {
-		registry.register(new JobSupport("foo"));
+		registry.register(new ReferenceJobFactory(new JobSupport("foo")));
 		assertNotNull(registry.getJob("foo"));
-		registry.unregister(new JobSupport("foo"));
+		registry.unregister("foo");
 		try {
 			assertNull(registry.getJob("foo"));
 			fail("Expected NoSuchJobConfigurationException");
@@ -55,12 +54,12 @@ public class MapJobRegistryTests extends TestCase {
 	 * Test method for {@link org.springframework.batch.execution.configuration.MapJobRegistry#getJob(java.lang.String)}.
 	 */
 	public void testReplaceDuplicateConfiguration() throws Exception {
-		registry.register(new JobSupport("foo"));
+		registry.register(new ReferenceJobFactory(new JobSupport("foo")));
 		try {
-			registry.register(new JobSupport("foo"));
+			registry.register(new ReferenceJobFactory(new JobSupport("foo")));
+			fail("Expected DuplicateJobConfigurationException");
 		} catch (DuplicateJobException e) {
-			fail("Unexpected DuplicateJobConfigurationException");
-			// expected
+			// unexpected: even if the job is different we want a DuplicateJobException
 			assertTrue(e.getMessage().indexOf("foo")>=0);
 		}
 	}
@@ -69,10 +68,10 @@ public class MapJobRegistryTests extends TestCase {
 	 * Test method for {@link org.springframework.batch.execution.configuration.MapJobRegistry#getJob(java.lang.String)}.
 	 */
 	public void testRealDuplicateConfiguration() throws Exception {
-		Job jobConfiguration = new JobSupport("foo");
-		registry.register(jobConfiguration);
+		JobFactory jobFactory = new ReferenceJobFactory(new JobSupport("foo"));
+		registry.register(jobFactory);
 		try {
-			registry.register(jobConfiguration);
+			registry.register(jobFactory);
 			fail("Unexpected DuplicateJobConfigurationException");
 		} catch (DuplicateJobException e) {
 			// expected
@@ -85,12 +84,12 @@ public class MapJobRegistryTests extends TestCase {
 	 * @throws Exception 
 	 */
 	public void testGetJobConfigurations() throws Exception {
-		Job configuration = new JobSupport("foo");
-		registry.register(configuration);
-		registry.register(new JobSupport("bar"));
+		JobFactory jobFactory = new ReferenceJobFactory(new JobSupport("foo"));
+		registry.register(jobFactory);
+		registry.register(new ReferenceJobFactory(new JobSupport("bar")));
 		Collection configurations = registry.getJobNames();
 		assertEquals(2, configurations.size());
-		assertTrue(configurations.contains(configuration.getName()));
+		assertTrue(configurations.contains(jobFactory.getJobName()));
 	}
 
 }

spring-batch-samples/src/main/java/org/springframework/batch/sample/tasklet/InfiniteLoopTasklet.java

@@ -18,6 +18,8 @@ package org.springframework.batch.sample.tasklet;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.springframework.batch.core.domain.StepExecution;
+import org.springframework.batch.core.listener.StepListenerSupport;
 import org.springframework.batch.core.tasklet.Tasklet;
 import org.springframework.batch.repeat.ExitStatus;
 
@@ -29,8 +31,9 @@ import org.springframework.batch.repeat.ExitStatus;
  * @author Lucas Ward
  * 
  */
-public class InfiniteLoopTasklet implements Tasklet {
+public class InfiniteLoopTasklet extends StepListenerSupport implements Tasklet {
 
+	private StepExecution stepExecution;
 	private int count = 0;
 	private static final Log logger = LogFactory.getLog(InfiniteLoopTasklet.class);
 
@@ -42,7 +45,7 @@ public class InfiniteLoopTasklet implements Tasklet {
 	}
 
 	public ExitStatus execute() throws Exception {
-		while(true) {
+		while(!stepExecution.isTerminateOnly()) {
 			try {
 				Thread.sleep(500);
 			} catch (InterruptedException e) {
@@ -52,6 +55,14 @@ public class InfiniteLoopTasklet implements Tasklet {
 			count++;
 			logger.info("Executing infinite loop, at count="+count);
 		}
+		return ExitStatus.FAILED;
+	}
+	
+	/* (non-Javadoc)
+	 * @see org.springframework.batch.core.listener.StepListenerSupport#beforeStep(org.springframework.batch.core.domain.StepExecution)
+	 */
+	public void beforeStep(StepExecution stepExecution) {
+		this.stepExecution = stepExecution;
 	}
 
 }

spring-batch-samples/src/test/java/org/springframework/batch/sample/ClassPathXmlApplicationContextJobFactory.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2006-2007 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.batch.sample;
+
+import org.springframework.batch.core.domain.Job;
+import org.springframework.batch.core.repository.JobFactory;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+/**
+ * A {@link JobFactory} that creates its own {@link ApplicationContext} from a
+ * path supplied, and pulls a bean out when asked to create a {@link Job}.
+ * 
+ * @author Dave Syer
+ * 
+ */
+public class ClassPathXmlApplicationContextJobFactory implements JobFactory {
+
+	private String beanName;
+
+	private String path;
+
+	private ApplicationContext parent;
+
+	/**
+	 * @param beanName
+	 * @param path
+	 */
+	public ClassPathXmlApplicationContextJobFactory(String beanName, String path, ApplicationContext parent) {
+		super();
+		this.beanName = beanName;
+		this.path = path;
+		this.parent = parent;
+	}
+
+	/**
+	 * Create a {@link ClassPathXmlApplicationContext} from the path provided
+	 * and pull out a bean with the name given during initialization.
+	 * 
+	 * @see org.springframework.batch.core.repository.JobFactory#createJob()
+	 */
+	public Job createJob() {
+		ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[] { path }, parent);
+		return (Job) context.getBean(beanName, Job.class);
+	}
+
+	/**
+	 * Return the bean name of the job in the application context. N.B. this is
+	 * usually the name of the job as well, but it needn't be. The important
+	 * thing is that the job can be located by this name.
+	 * 
+	 * @see org.springframework.batch.core.repository.JobFactory#getJobName()
+	 */
+	public String getJobName() {
+		return beanName;
+	}
+
+}

spring-batch-samples/src/test/java/org/springframework/batch/sample/TaskExecutorLauncher.java

@@ -15,53 +15,96 @@
  */
 package org.springframework.batch.sample;
 
+import org.springframework.batch.core.domain.Job;
+import org.springframework.batch.core.repository.DuplicateJobException;
 import org.springframework.batch.core.repository.JobRegistry;
+import org.springframework.beans.factory.config.AutowireCapableBeanFactory;
+import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.beans.factory.xml.XmlBeanFactory;
 import org.springframework.context.ApplicationContext;
+import org.springframework.context.ResourceLoaderAware;
 import org.springframework.context.support.ClassPathXmlApplicationContext;
+import org.springframework.core.io.ResourceLoader;
 
 /**
  * @author Dave Syer
  * 
  */
-public class TaskExecutorLauncher {
-	
+public class TaskExecutorLauncher implements ResourceLoaderAware {
+
 	private JobRegistry registry;
-	
-	private void register(String[] paths) {
-		// registry.register(jobConfiguration)
+
+	private ResourceLoader resourceLoader;
+
+	private ApplicationContext parentContext = null;
+
+	/**
+	 * Public setter for the {@link JobRegistry}.
+	 * @param registry the registry to set
+	 */
+	public void setRegistry(JobRegistry registry) {
+		this.registry = registry;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.context.ResourceLoaderAware#setResourceLoader(org.springframework.core.io.ResourceLoader)
+	 */
+	public void setResourceLoader(ResourceLoader resourceLoader) {
+		this.resourceLoader = resourceLoader;
+	}
+
+	private void register(String[] paths) throws DuplicateJobException {
+		for (int i = 0; i < paths.length; i++) {
+			String path = paths[i];
+			ConfigurableListableBeanFactory beanFactory = new XmlBeanFactory(resourceLoader.getResource(path),
+					parentContext.getAutowireCapableBeanFactory());
+			String[] names = beanFactory.getBeanNamesForType(Job.class);
+			for (int j = 0; j < names.length; j++) {
+				registry.register(new ClassPathXmlApplicationContextJobFactory(names[j], path, parentContext));
+			}
+		}
 	}
 
 	public static void main(String[] args) throws Exception {
 
-		// Paths to individual job configurations.
-		final String[] paths = new String[] { "jobs/adhocLoopJob.xml",
-				"jobs/footballJob.xml" };
-
-		// The simple execution environment will be used as a parent
-		// context for each of the job contexts. The standard version of this
-		// from the Spring Batch samples does not have an MBean for the
-		// JobLauncher, nor does the JobLauncher have an asynchronous
-		// TaskExecutor. The adhocLoopJob has both, which is why it has to be
-		// included in the paths above.
-		final ApplicationContext parent = new ClassPathXmlApplicationContext(
-				"adhoc-job-launcher-context.xml");
-//		parent.getAutowireCapableBeanFactory().autowireBeanProperties(
-//				this, AutowireCapableBeanFactory.AUTOWIRE_BY_TYPE, false);
+		final TaskExecutorLauncher launcher = new TaskExecutorLauncher();
 
 		new Thread(new Runnable() {
 			public void run() {
-				for (int i = 0; i < paths.length; i++) {
-					String path = paths[i];
-					new ClassPathXmlApplicationContext(new String[] { path },
-							parent);
-				}
+				launcher.run();
 			};
 		}).start();
 
+		while (launcher.parentContext == null) {
+			Thread.sleep(100L);
+		}
+
+		// Paths to individual job configurations.
+		final String[] paths = new String[] { "jobs/adhocLoopJob.xml", "jobs/footballJob.xml" };
+
+		launcher.register(paths);
+
 		System.out
 				.println("Started application.  "
 						+ "Please connect using JMX (remember to use -Dcom.sun.management.jmxremote if you can't see anything in Jconsole).");
 		System.in.read();
 
 	}
+
+	private void run() {
+
+		/*
+		 * A simple execution environment with an MBean for the JobLauncher,
+		 * which has an asynchronous TaskExecutor. This will be used as the
+		 * parent context for loading job configurations.
+		 */
+		final ApplicationContext parent = new ClassPathXmlApplicationContext("adhoc-job-launcher-context.xml");
+		parent.getAutowireCapableBeanFactory().autowireBeanProperties(this,
+				AutowireCapableBeanFactory.AUTOWIRE_BY_TYPE, false);
+		parent.getAutowireCapableBeanFactory().initializeBean(this, "taskExecutorLauncher");
+		this.parentContext = parent;
+
+	}
+
 }