RESOLVED - issue BATCH-1411: Allow a Job to specify its required JobParameters

spring-batch-core/src/main/java/org/springframework/batch/core/Job.java

@@ -34,7 +34,7 @@ public interface Job {
 	 * @return true if this job can be restarted after a failure
 	 */
 	boolean isRestartable();
-
+	
 	/**
 	 * Run the {@link JobExecution} and update the meta information like status
 	 * and statistics as necessary. This method should not throw any exceptions
@@ -54,4 +54,6 @@ public interface Job {
 	 */
 	JobParametersIncrementer getJobParametersIncrementer();
 
+	void validate(JobParameters parameters) throws JobParametersInvalidException;
+
 }

spring-batch-core/src/main/java/org/springframework/batch/core/JobParametersInvalidException.java

@@ -0,0 +1,16 @@
+package org.springframework.batch.core;
+
+/**
+ * Exception for {@link Job} to signal that some {@link JobParameters} are
+ * invalid.
+ * 
+ * @author Dave Syer
+ * 
+ */
+public class JobParametersInvalidException extends JobExecutionException {
+
+	public JobParametersInvalidException(String msg) {
+		super(msg);
+	}
+
+}

spring-batch-core/src/main/java/org/springframework/batch/core/configuration/support/GroupAwareJob.java

@@ -17,7 +17,9 @@ package org.springframework.batch.core.configuration.support;
 
 import org.springframework.batch.core.Job;
 import org.springframework.batch.core.JobExecution;
+import org.springframework.batch.core.JobParameters;
 import org.springframework.batch.core.JobParametersIncrementer;
+import org.springframework.batch.core.JobParametersInvalidException;
 
 /**
  * A {@link Job} that can optionally prepend a group name to another job's name,
@@ -68,6 +70,10 @@ public class GroupAwareJob implements Job {
 	public void execute(JobExecution execution) {
 		delegate.execute(execution);
 	}
+	
+	public void validate(JobParameters parameters) throws JobParametersInvalidException {
+		delegate.validate(parameters);
+	}
 
 	/**
 	 * Concatenates the group name and the delegate job name (joining with a

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

@@ -76,6 +76,11 @@ public class JobParser extends AbstractSingleBeanDefinitionParser {
 			builder.addPropertyReference("jobRepository", repositoryAttribute);
 		}
 
+		String parametersValidator = element.getAttribute("parameters-validator");
+		if (StringUtils.hasText(parametersValidator)) {
+			builder.addPropertyReference("jobParametersValidator", parametersValidator);
+		}
+
 		String restartableAttribute = element.getAttribute("restartable");
 		if (StringUtils.hasText(restartableAttribute)) {
 			builder.addPropertyValue("restartable", restartableAttribute);

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

@@ -17,6 +17,7 @@ package org.springframework.batch.core.configuration.xml;
 
 import org.springframework.batch.core.JobExecutionListener;
 import org.springframework.batch.core.JobParametersIncrementer;
+import org.springframework.batch.core.job.JobParametersValidator;
 import org.springframework.batch.core.job.flow.Flow;
 import org.springframework.batch.core.job.flow.FlowJob;
 import org.springframework.batch.core.repository.JobRepository;
@@ -42,6 +43,8 @@ class JobParserJobFactoryBean implements SmartFactoryBean {
 
 	private JobRepository jobRepository;
 
+	private JobParametersValidator jobParametersValidator;
+
 	private JobExecutionListener[] jobExecutionListeners;
 
 	private JobParametersIncrementer jobParametersIncrementer;
@@ -64,6 +67,10 @@ class JobParserJobFactoryBean implements SmartFactoryBean {
 			flowJob.setJobRepository(jobRepository);
 		}
 
+		if (jobParametersValidator != null) {
+			flowJob.setJobParametersValidator(jobParametersValidator);
+		}
+
 		if (jobExecutionListeners != null) {
 			flowJob.setJobExecutionListeners(jobExecutionListeners);
 		}
@@ -87,6 +94,10 @@ class JobParserJobFactoryBean implements SmartFactoryBean {
 	public void setJobRepository(JobRepository jobRepository) {
 		this.jobRepository = jobRepository;
 	}
+	
+	public void setJobParametersValidator(JobParametersValidator jobParametersValidator) {
+		this.jobParametersValidator = jobParametersValidator;
+	}
 
 	public JobRepository getJobRepository() {
 		return this.jobRepository;

spring-batch-core/src/main/java/org/springframework/batch/core/job/AbstractJob.java

@@ -29,7 +29,9 @@ import org.springframework.batch.core.JobExecutionException;
 import org.springframework.batch.core.JobExecutionListener;
 import org.springframework.batch.core.JobInstance;
 import org.springframework.batch.core.JobInterruptedException;
+import org.springframework.batch.core.JobParameters;
 import org.springframework.batch.core.JobParametersIncrementer;
+import org.springframework.batch.core.JobParametersInvalidException;
 import org.springframework.batch.core.StartLimitExceededException;
 import org.springframework.batch.core.Step;
 import org.springframework.batch.core.StepExecution;
@@ -45,10 +47,10 @@ import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 
 /**
- * Abstract implementation of the {@link Job} interface.  Common dependencies such as a
- * {@link JobRepository}, {@link JobExecutionListener}s, and various configuration 
- * parameters are set here.  Therefore, common error handling and listener calling
- * activities are abstracted away from implementations.
+ * Abstract implementation of the {@link Job} interface. Common dependencies
+ * such as a {@link JobRepository}, {@link JobExecutionListener}s, and various
+ * configuration parameters are set here. Therefore, common error handling and
+ * listener calling activities are abstracted away from implementations.
  * 
  * @author Lucas Ward
  * @author Dave Syer
@@ -67,6 +69,8 @@ public abstract class AbstractJob implements Job, StepLocator, BeanNameAware, In
 
 	private JobParametersIncrementer jobParametersIncrementer;
 
+	private JobParametersValidator jobParametersValidator = new DefaultJobParametersValidator();
+
 	/**
 	 * Default constructor.
 	 */
@@ -85,6 +89,26 @@ public abstract class AbstractJob implements Job, StepLocator, BeanNameAware, In
 		this.name = name;
 	}
 
+	/**
+	 * A validator for job parameters. Defaults to a vanilla
+	 * {@link DefaultJobParametersValidator}.
+	 * 
+	 * @param jobParametersValidator a validator instance
+	 */
+	public void setJobParametersValidator(JobParametersValidator jobParametersValidator) {
+		this.jobParametersValidator = jobParametersValidator;
+	}
+
+	/**
+	 * Delegates to the {@link #setJobParametersValidator validator} supplied
+	 * (defaults to just checking for null parameters).
+	 * 
+	 * @see Job#validate(JobParameters)
+	 */
+	public void validate(JobParameters parameters) throws JobParametersInvalidException {
+		jobParametersValidator.validate(parameters);
+	}
+
 	/**
 	 * Assert mandatory properties: {@link JobRepository}.
 	 * 
@@ -129,21 +153,21 @@ public abstract class AbstractJob implements Job, StepLocator, BeanNameAware, In
 	}
 
 	/**
-	 * Retrieve the step with the given name. If there is no Step with the
-	 * given name, then return null.
+	 * Retrieve the step with the given name. If there is no Step with the given
+	 * name, then return null.
 	 * 
 	 * @param stepName
 	 * @return the Step
 	 */
 	public abstract Step getStep(String stepName);
-	
+
 	/**
 	 * Retrieve the step names.
 	 * 
 	 * @return the step names
 	 */
 	public abstract Collection<String> getStepNames();
-	
+
 	/**
 	 * Boolean flag to prevent categorically a job from restarting, even if it
 	 * has failed previously.
@@ -235,7 +259,7 @@ public abstract class AbstractJob implements Job, StepLocator, BeanNameAware, In
 	 */
 	public final void execute(JobExecution execution) {
 
-		logger.debug("Job execution starting: "+execution);					
+		logger.debug("Job execution starting: " + execution);
 
 		try {
 
@@ -248,8 +272,9 @@ public abstract class AbstractJob implements Job, StepLocator, BeanNameAware, In
 
 				try {
 					doExecute(execution);
-					logger.debug("Job execution complete: "+execution);					
-				} catch (RepeatException e) {
+					logger.debug("Job execution complete: " + execution);
+				}
+				catch (RepeatException e) {
 					throw e.getCause();
 				}
 			}
@@ -259,7 +284,7 @@ public abstract class AbstractJob implements Job, StepLocator, BeanNameAware, In
 				// with it in the same way as any other interruption.
 				execution.setStatus(BatchStatus.STOPPED);
 				execution.setExitStatus(ExitStatus.COMPLETED);
-				logger.debug("Job execution was stopped: "+execution);					
+				logger.debug("Job execution was stopped: " + execution);
 
 			}
 
@@ -291,9 +316,9 @@ public abstract class AbstractJob implements Job, StepLocator, BeanNameAware, In
 			catch (Exception e) {
 				logger.error("Exception encountered in afterStep callback", e);
 			}
-			
+
 			jobRepository.update(execution);
-			
+
 		}
 
 	}
@@ -347,9 +372,10 @@ public abstract class AbstractJob implements Job, StepLocator, BeanNameAware, In
 			logger.info("Executing step: [" + step + "]");
 			try {
 				step.execute(currentStepExecution);
-			} catch (JobInterruptedException e) {
+			}
+			catch (JobInterruptedException e) {
 				// Ensure that the job gets the message that it is stopping
-				// and can pass it on to other steps that are executing 
+				// and can pass it on to other steps that are executing
 				// concurrently.
 				execution.setStatus(BatchStatus.STOPPING);
 				throw e;
@@ -357,13 +383,15 @@ public abstract class AbstractJob implements Job, StepLocator, BeanNameAware, In
 
 			jobRepository.updateExecutionContext(execution);
 
-			if (currentStepExecution.getStatus() == BatchStatus.STOPPING || currentStepExecution.getStatus() == BatchStatus.STOPPED) {
+			if (currentStepExecution.getStatus() == BatchStatus.STOPPING
+					|| currentStepExecution.getStatus() == BatchStatus.STOPPED) {
 				// Ensure that the job gets the message that it is stopping
 				execution.setStatus(BatchStatus.STOPPING);
 				throw new JobInterruptedException("Job interrupted by step execution");
 			}
 
-		} else {
+		}
+		else {
 			// currentStepExecution.setExitStatus(ExitStatus.NOOP);
 		}
 
@@ -411,11 +439,11 @@ public abstract class AbstractJob implements Job, StepLocator, BeanNameAware, In
 					+ "so it may be dangerous to proceed.  " + "Manual intervention is probably necessary.");
 		}
 
-		if ((stepStatus == BatchStatus.COMPLETED && step.isAllowStartIfComplete() == false) 
+		if ((stepStatus == BatchStatus.COMPLETED && step.isAllowStartIfComplete() == false)
 				|| stepStatus == BatchStatus.ABANDONED) {
 			// step is complete, false should be returned, indicating that the
 			// step should not be started
-			logger.info("Step already complete or not restartable, so no action to execute: "+lastStepExecution);
+			logger.info("Step already complete or not restartable, so no action to execute: " + lastStepExecution);
 			return false;
 		}
 

spring-batch-core/src/main/java/org/springframework/batch/core/job/DefaultJobParametersValidator.java

@@ -0,0 +1,75 @@
+package org.springframework.batch.core.job;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashSet;
+
+import org.springframework.batch.core.JobParameters;
+import org.springframework.batch.core.JobParametersInvalidException;
+import org.springframework.beans.factory.InitializingBean;
+import org.springframework.util.Assert;
+
+/**
+ * Default implementation of {@link JobParametersValidator}.
+ * 
+ * @author Dave Syer
+ * 
+ */
+public class DefaultJobParametersValidator implements JobParametersValidator, InitializingBean {
+
+	private Collection<String> requiredKeys = new HashSet<String>();
+
+	private Collection<String> optionalKeys = new HashSet<String>();
+
+	/**
+	 * Check that there are no overlaps between required and optional keys.
+	 * @throws IllegalStateException if there is an overlap
+	 */
+	public void afterPropertiesSet() throws IllegalStateException {
+		for (String key : requiredKeys) {
+			Assert.state(!optionalKeys.contains(key), "Optional keys canot be required: "+key);
+		}
+	}
+
+	/**
+	 * Check the parameters meet the specification provided.
+	 * 
+	 * @see JobParametersValidator#validate(JobParameters)
+	 */
+	public void validate(JobParameters parameters) throws JobParametersInvalidException {
+
+		if (parameters == null) {
+			throw new JobParametersInvalidException("The JobParameters can not be null");
+		}
+
+		Collection<String> missingKeys = new HashSet<String>();
+		for (String key : requiredKeys) {
+			if (!parameters.getParameters().containsKey(key)) {
+				missingKeys.add(key);
+			}
+		}
+		if (!missingKeys.isEmpty()) {
+			throw new JobParametersInvalidException("The JobParameters do not contain required keys: " + missingKeys);
+		}
+
+	}
+
+	/**
+	 * The keys that are required in the parameters.
+	 * 
+	 * @param requiredKeys the required key values
+	 */
+	public void setRequiredKeys(String[] requiredKeys) {
+		this.requiredKeys = new HashSet<String>(Arrays.asList(requiredKeys));
+	}
+
+	/**
+	 * The keys that are optional in the parameters.
+	 * 
+	 * @param optionalKeys the optional key values
+	 */
+	public void setOptionalKeys(String[] optionalKeys) {
+		this.optionalKeys = new HashSet<String>(Arrays.asList(optionalKeys));
+	}
+
+}

spring-batch-core/src/main/java/org/springframework/batch/core/job/JobParametersValidator.java

@@ -0,0 +1,24 @@
+package org.springframework.batch.core.job;
+
+import org.springframework.batch.core.Job;
+import org.springframework.batch.core.JobParameters;
+import org.springframework.batch.core.JobParametersInvalidException;
+
+/**
+ * Strategy interface for a {@link Job} to use in validating parameters.
+ * 
+ * @author Dave Syer
+ * 
+ */
+public interface JobParametersValidator {
+
+	/**
+	 * Check the parameters meet whatever requirements are appropriate, and
+	 * throw an exception if not.
+	 * 
+	 * @param parameters some {@link JobParameters}
+	 * @throws JobParametersInvalidException if the parameters are invalid
+	 */
+	void validate(JobParameters parameters) throws JobParametersInvalidException;
+
+}

spring-batch-core/src/main/java/org/springframework/batch/core/launch/JobLauncher.java

@@ -18,6 +18,7 @@ package org.springframework.batch.core.launch;
 import org.springframework.batch.core.Job;
 import org.springframework.batch.core.JobExecution;
 import org.springframework.batch.core.JobParameters;
+import org.springframework.batch.core.JobParametersInvalidException;
 import org.springframework.batch.core.repository.JobExecutionAlreadyRunningException;
 import org.springframework.batch.core.repository.JobInstanceAlreadyCompleteException;
 import org.springframework.batch.core.repository.JobRestartException;
@@ -42,8 +43,8 @@ public interface JobLauncher {
 	 * always be returned by this method, regardless of whether or not the
 	 * execution was successful. If there is a past {@link JobExecution} which
 	 * has paused, the same {@link JobExecution} is returned instead of a new
-	 * one created.  A exception will only be thrown if there is a failure to
-	 * start the job.  If the job encounters some error while processing, the
+	 * one created. A exception will only be thrown if there is a failure to
+	 * start the job. If the job encounters some error while processing, the
 	 * JobExecution will be returned, and the status will need to be inspected.
 	 * 
 	 * @return the {@link JobExecution} if it returns synchronously. If the
@@ -57,8 +58,10 @@ public interface JobLauncher {
 	 * circumstances that preclude a re-start.
 	 * @throws JobInstanceAlreadyCompleteException if the job has been run
 	 * before with the same parameters and completed successfully
+	 * @throws JobParametersInvalidException if the parameters are not valid for
+	 * this job
 	 */
 	public JobExecution run(Job job, JobParameters jobParameters) throws JobExecutionAlreadyRunningException,
-			JobRestartException, JobInstanceAlreadyCompleteException;
+			JobRestartException, JobInstanceAlreadyCompleteException, JobParametersInvalidException;
 
 }

spring-batch-core/src/main/java/org/springframework/batch/core/launch/JobOperator.java

@@ -24,6 +24,7 @@ import org.springframework.batch.core.JobExecution;
 import org.springframework.batch.core.JobInstance;
 import org.springframework.batch.core.JobParameters;
 import org.springframework.batch.core.JobParametersIncrementer;
+import org.springframework.batch.core.JobParametersInvalidException;
 import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.UnexpectedJobExecutionException;
 import org.springframework.batch.core.repository.JobExecutionAlreadyRunningException;
@@ -31,10 +32,10 @@ import org.springframework.batch.core.repository.JobInstanceAlreadyCompleteExcep
 import org.springframework.batch.core.repository.JobRestartException;
 
 /**
- * Low level interface for inspecting and controlling jobs with access
- * only to primitive and collection types. Suitable for a command-line client
- * (e.g. that launches a new process for each operation), or a remote launcher
- * like a JMX console.
+ * Low level interface for inspecting and controlling jobs with access only to
+ * primitive and collection types. Suitable for a command-line client (e.g. that
+ * launches a new process for each operation), or a remote launcher like a JMX
+ * console.
  * 
  * @author Dave Syer
  * @since 2.0
@@ -98,8 +99,9 @@ public interface JobOperator {
 	 * name
 	 * @throws JobInstanceAlreadyExistsException if a job instance with this
 	 * name and parameters already exists
+	 * @throws JobParametersInvalidException 
 	 */
-	Long start(String jobName, String parameters) throws NoSuchJobException, JobInstanceAlreadyExistsException;
+	Long start(String jobName, String parameters) throws NoSuchJobException, JobInstanceAlreadyExistsException, JobParametersInvalidException;
 
 	/**
 	 * Restart a failed or stopped {@link JobExecution}. Fails with an exception
@@ -117,9 +119,11 @@ public interface JobOperator {
 	 * corresponding {@link Job} is no longer available for launching
 	 * @throws JobRestartException if there is a non-specific error with the
 	 * restart (e.g. corrupt or inconsistent restart data)
+	 * @throws JobParametersInvalidException if the parameters are not valid for
+	 * this job
 	 */
 	Long restart(long executionId) throws JobInstanceAlreadyCompleteException, NoSuchJobExecutionException,
-			NoSuchJobException, JobRestartException;
+			NoSuchJobException, JobRestartException, JobParametersInvalidException;
 
 	/**
 	 * Launch the next in a sequence of {@link JobInstance} determined by the
@@ -138,10 +142,12 @@ public interface JobOperator {
 	 * is launched
 	 * @throws NoSuchJobException if there is no such job definition available
 	 * @throws JobParametersNotFoundException if the parameters cannot be found
+	 * @throws JobParametersInvalidException 
+	 * @throws UnexpectedJobExecutionException 
 	 * @throws UnexpectedJobExecutionException if an unexpected condition arises
 	 */
 	Long startNextInstance(String jobName) throws NoSuchJobException, JobParametersNotFoundException,
-			JobRestartException, JobExecutionAlreadyRunningException, JobInstanceAlreadyCompleteException;
+			JobRestartException, JobExecutionAlreadyRunningException, JobInstanceAlreadyCompleteException, UnexpectedJobExecutionException, JobParametersInvalidException;
 
 	/**
 	 * Send a stop signal to the {@link JobExecution} with the supplied id. The

spring-batch-core/src/main/java/org/springframework/batch/core/launch/support/SimpleJobLauncher.java

@@ -21,6 +21,7 @@ import org.springframework.batch.core.Job;
 import org.springframework.batch.core.JobExecution;
 import org.springframework.batch.core.JobInstance;
 import org.springframework.batch.core.JobParameters;
+import org.springframework.batch.core.JobParametersInvalidException;
 import org.springframework.batch.core.launch.JobLauncher;
 import org.springframework.batch.core.repository.JobExecutionAlreadyRunningException;
 import org.springframework.batch.core.repository.JobInstanceAlreadyCompleteException;
@@ -74,13 +75,18 @@ public class SimpleJobLauncher implements JobLauncher, InitializingBean {
 	 * re-start is either not allowed or not needed.
 	 * @throws JobInstanceAlreadyCompleteException if this instance has already
 	 * completed successfully
+	 * @throws JobParametersInvalidException
 	 */
 	public JobExecution run(final Job job, final JobParameters jobParameters)
-			throws JobExecutionAlreadyRunningException, JobRestartException, JobInstanceAlreadyCompleteException {
+			throws JobExecutionAlreadyRunningException, JobRestartException, JobInstanceAlreadyCompleteException,
+			JobParametersInvalidException {
 
 		Assert.notNull(job, "The Job must not be null.");
 		Assert.notNull(jobParameters, "The JobParameters must not be null.");
 
+		// Allow the job to veto the execution
+		job.validate(jobParameters);
+
 		final JobExecution jobExecution;
 		JobExecution lastExecution = jobRepository.getLastJobExecution(job.getName(), jobParameters);
 		if (lastExecution != null) {
@@ -112,7 +118,8 @@ public class SimpleJobLauncher implements JobLauncher, InitializingBean {
 							+ "] and the following status: [" + jobExecution.getStatus() + "]");
 				}
 				catch (Throwable t) {
-					logger.info("Job: [" + job + "] failed unexpectedly and fatally with the following parameters: [" + jobParameters + "]", t);
+					logger.info("Job: [" + job + "] failed unexpectedly and fatally with the following parameters: ["
+							+ jobParameters + "]", t);
 					rethrow(t);
 				}
 			}

spring-batch-core/src/main/java/org/springframework/batch/core/launch/support/SimpleJobOperator.java

@@ -31,6 +31,7 @@ import org.springframework.batch.core.JobExecution;
 import org.springframework.batch.core.JobInstance;
 import org.springframework.batch.core.JobParameters;
 import org.springframework.batch.core.JobParametersIncrementer;
+import org.springframework.batch.core.JobParametersInvalidException;
 import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.UnexpectedJobExecutionException;
 import org.springframework.batch.core.configuration.JobRegistry;
@@ -251,7 +252,7 @@ public class SimpleJobOperator implements JobOperator, InitializingBean {
 	 * org.springframework.batch.core.launch.JobOperator#resume(java.lang.Long)
 	 */
 	public Long restart(long executionId) throws JobInstanceAlreadyCompleteException, NoSuchJobExecutionException,
-			NoSuchJobException, JobRestartException {
+			NoSuchJobException, JobRestartException, JobParametersInvalidException {
 
 		logger.info("Checking status of job execution with id=" + executionId);
 
@@ -279,7 +280,7 @@ public class SimpleJobOperator implements JobOperator, InitializingBean {
 	 * org.springframework.batch.core.launch.JobOperator#start(java.lang.String,
 	 * java.lang.String)
 	 */
-	public Long start(String jobName, String parameters) throws NoSuchJobException, JobInstanceAlreadyExistsException {
+	public Long start(String jobName, String parameters) throws NoSuchJobException, JobInstanceAlreadyExistsException, JobParametersInvalidException {
 
 		logger.info("Checking status of job with name=" + jobName);
 
@@ -319,7 +320,7 @@ public class SimpleJobOperator implements JobOperator, InitializingBean {
 	 * @see JobOperator#startNextInstance(String )
 	 */
 	public Long startNextInstance(String jobName) throws NoSuchJobException, JobParametersNotFoundException,
-			UnexpectedJobExecutionException {
+			UnexpectedJobExecutionException, JobParametersInvalidException {
 
 		logger.info("Locating parameters for next instance of job with name=" + jobName);
 

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

@@ -1,8 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<xsd:schema xmlns="http://www.springframework.org/schema/batch" xmlns:xsd="http://www.w3.org/2001/XMLSchema"
-	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+<xsd:schema xmlns="http://www.springframework.org/schema/batch"
+	xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 	xmlns:beans="http://www.springframework.org/schema/beans" xmlns:tool="http://www.springframework.org/schema/tool"
-	targetNamespace="http://www.springframework.org/schema/batch" elementFormDefault="qualified" attributeFormDefault="unqualified"
+	targetNamespace="http://www.springframework.org/schema/batch"
+	elementFormDefault="qualified" attributeFormDefault="unqualified"
 	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
 	http://www.springframework.org/schema/tool http://www.springframework.org/schema/tool/spring-tool-2.5.xsd"
 	version="2.1">
@@ -21,13 +22,15 @@
 			<xsd:documentation>
 				Defines a job composed of a set of steps and
 				transitions between steps. The job will be exposed in
-				the enclosing bean factory as a component of type Job
-				that can be launched using a JobLauncher.
+				the enclosing
+				bean factory as a component of type Job
+				that can be launched using a
+				JobLauncher.
 			</xsd:documentation>
 		</xsd:annotation>
 		<xsd:complexType>
 			<xsd:sequence>
-				<xsd:element ref="description" minOccurs="0"/>
+				<xsd:element ref="description" minOccurs="0" />
 				<xsd:choice minOccurs="0" maxOccurs="unbounded">
 					<xsd:group ref="flowGroup" />
 					<xsd:element name="listeners">
@@ -39,7 +42,8 @@
 						</xsd:annotation>
 						<xsd:complexType>
 							<xsd:sequence>
-								<xsd:element name="listener" type="jobExecutionListenerType" minOccurs="0" maxOccurs="unbounded" />
+								<xsd:element name="listener" type="jobExecutionListenerType"
+									minOccurs="0" maxOccurs="unbounded" />
 							</xsd:sequence>
 							<xsd:attributeGroup ref="mergeAttribute" />
 						</xsd:complexType>
@@ -48,7 +52,22 @@
 			</xsd:sequence>
 			<xsd:attribute name="id" type="xsd:ID" use="required" />
 			<xsd:attributeGroup ref="jobRepositoryAttribute" />
-			<xsd:attribute name="incrementer" type="xsd:string" use="optional">
+			<xsd:attribute name="parameters-validator" type="xsd:string">
+				<xsd:annotation>
+					<xsd:documentation
+						source="java:org.springframework.batch.core.job.JobParametersValidator"><![CDATA[
+				The bean name of the JobParametersValidator to use.
+				]]></xsd:documentation>
+					<xsd:appinfo>
+						<tool:annotation kind="ref">
+							<tool:expected-type
+								type="org.springframework.batch.core.job.JobParametersValidator" />
+						</tool:annotation>
+					</xsd:appinfo>
+				</xsd:annotation>
+			</xsd:attribute>
+			<xsd:attribute name="incrementer" type="xsd:string"
+				use="optional">
 				<xsd:annotation>
 					<xsd:documentation><![CDATA[ 
 						A reference to a JobParametersIncrementer bean definition.  This will be 
@@ -58,11 +77,13 @@
 					</xsd:documentation>
 					<xsd:appinfo>
 						<tool:annotation kind="ref" />
-						<tool:expected-type type="org.springframework.batch.core.JobParametersIncrementer" />
+						<tool:expected-type
+							type="org.springframework.batch.core.JobParametersIncrementer" />
 					</xsd:appinfo>
 				</xsd:annotation>
 			</xsd:attribute>
-			<xsd:attribute name="restartable" type="xsd:string" use="optional">
+			<xsd:attribute name="restartable" type="xsd:string"
+				use="optional">
 				<xsd:annotation>
 					<xsd:documentation><![CDATA[
 					Whether the job should be retartable or not in case of failure.  Set this to false
@@ -80,19 +101,20 @@
 			<xsd:documentation>
 				Defines a stage in job processing backed by a
 				Step. The id attribute must be specified since this
-				step definition will be referred to from other elements
+				step definition
+				will be referred to from other elements
 				to form a Job flow.
 			</xsd:documentation>
 		</xsd:annotation>
 		<xsd:complexType>
 			<xsd:sequence>
-				<xsd:element ref="description" minOccurs="0"/>
+				<xsd:element ref="description" minOccurs="0" />
 				<xsd:choice minOccurs="0" maxOccurs="1">
 					<xsd:element name="tasklet">
 						<xsd:complexType>
 							<xsd:complexContent>
 								<xsd:extension base="taskletType">
-									<xsd:attributeGroup ref="jobRepositoryAttribute"/>
+									<xsd:attributeGroup ref="jobRepositoryAttribute" />
 								</xsd:extension>
 							</xsd:complexContent>
 						</xsd:complexType>
@@ -100,7 +122,7 @@
 				</xsd:choice>
 			</xsd:sequence>
 			<xsd:attribute name="id" type="xsd:ID" use="required" />
-			<xsd:attributeGroup ref="parentAttribute"/>
+			<xsd:attributeGroup ref="parentAttribute" />
 			<xsd:attributeGroup ref="abstractAttribute" />
 		</xsd:complexType>
 	</xsd:element>
@@ -110,7 +132,8 @@
 			<xsd:documentation>
 				A reference to a JobExecutionListener (or a POJO
 				if using before-job-method / after-job-method or
-				source level annotations).
+				source level
+				annotations).
 			</xsd:documentation>
 		</xsd:annotation>
 		<xsd:complexType>
@@ -125,7 +148,8 @@
 	<xsd:element name="step-listener">
 		<xsd:annotation>
 			<xsd:documentation>
-				A bean definition for a step listener (or POJO if using *-method attributes or source level
+				A bean definition for a step listener (or POJO if
+				using *-method attributes or source level
 				annotations)
 			</xsd:documentation>
 		</xsd:annotation>
@@ -148,7 +172,8 @@
 		<xsd:complexType>
 			<xsd:complexContent>
 				<xsd:extension base="beans:identifiedType">
-					<xsd:attribute name="data-source" type="xsd:string" default="dataSource">
+					<xsd:attribute name="data-source" type="xsd:string"
+						default="dataSource">
 						<xsd:annotation>
 							<xsd:documentation source="java:javax.sql.DataSource"><![CDATA[
 							The bean name of the DataSource that is to be used. This attribute 
@@ -162,7 +187,8 @@
 							</xsd:appinfo>
 						</xsd:annotation>
 					</xsd:attribute>
-					<xsd:attribute name="transaction-manager" type="xsd:string" default="transactionManager">
+					<xsd:attribute name="transaction-manager" type="xsd:string"
+						default="transactionManager">
 						<xsd:annotation>
 							<xsd:documentation
 								source="java:org.springframework.transaction.PlatformTransactionManager"><![CDATA[
@@ -178,7 +204,8 @@
 							</xsd:appinfo>
 						</xsd:annotation>
 					</xsd:attribute>
-					<xsd:attribute name="isolation-level-for-create" default="SERIALIZABLE" type="isolationType">
+					<xsd:attribute name="isolation-level-for-create"
+						default="SERIALIZABLE" type="isolationType">
 						<xsd:annotation>
 							<xsd:documentation><![CDATA[
 							The isolation level to use for creation of job execution entities.
@@ -231,28 +258,30 @@
 					<xsd:documentation>
 						Defines a stage in job processing backed by a
 						Step. The id attribute must be specified. The
-						step requires either a chunk definition,
-						a tasklet reference, or a reference to a 
+						step requires either
+						a chunk definition,
+						a tasklet reference, or a reference to a
 						(possibly abstract) parent step.
 					</xsd:documentation>
 				</xsd:annotation>
 				<xsd:complexType>
 					<xsd:sequence>
-						<xsd:element ref="description" minOccurs="0"/>
+						<xsd:element ref="description" minOccurs="0" />
 						<xsd:choice minOccurs="0" maxOccurs="unbounded">
-							<xsd:element name="tasklet" type="taskletType"/>
+							<xsd:element name="tasklet" type="taskletType" />
 							<xsd:group ref="transitions" />
 						</xsd:choice>
 					</xsd:sequence>
 					<xsd:attribute name="id" type="xsd:ID" use="required" />
-					<xsd:attributeGroup ref="parentAttribute"/>
+					<xsd:attributeGroup ref="parentAttribute" />
 					<xsd:attributeGroup ref="nextAttribute" />
 				</xsd:complexType>
 			</xsd:element>
 			<xsd:element name="split">
 				<xsd:annotation>
 					<xsd:documentation>
-						Declares job should split here into two or more subflows.
+						Declares job should split here into two or more
+						subflows.
 					</xsd:documentation>
 				</xsd:annotation>
 				<xsd:complexType>
@@ -260,7 +289,8 @@
 						<xsd:element name="flow">
 							<xsd:annotation>
 								<xsd:documentation>
-									A subflow within a job, having the same format as a job, but without a separate identity.
+									A subflow within a job, having the same
+									format as a job, but without a separate identity.
 								</xsd:documentation>
 							</xsd:annotation>
 							<xsd:complexType>
@@ -270,14 +300,17 @@
 						<xsd:group ref="transitions" />
 					</xsd:choice>
 					<xsd:attribute name="id" type="xsd:ID" use="required" />
-					<xsd:attribute name="task-executor" type="xsd:string" use="optional">
+					<xsd:attribute name="task-executor" type="xsd:string"
+						use="optional">
 						<xsd:annotation>
-							<xsd:documentation source="java:org.springframework.core.task.TaskExecutor"><![CDATA[
+							<xsd:documentation
+								source="java:org.springframework.core.task.TaskExecutor"><![CDATA[
 							The task executor responsible for executing the task.
 							]]></xsd:documentation>
 							<xsd:appinfo>
 								<tool:annotation kind="ref">
-									<tool:expected-type type="org.springframework.core.task.TaskExecutor" />
+									<tool:expected-type
+										type="org.springframework.core.task.TaskExecutor" />
 								</tool:annotation>
 							</xsd:appinfo>
 						</xsd:annotation>
@@ -288,7 +321,8 @@
 			<xsd:element name="decision">
 				<xsd:annotation>
 					<xsd:documentation>
-						Declares job should query a decider to determine where execution should go next.
+						Declares job should query a decider to determine
+						where execution should go next.
 					</xsd:documentation>
 				</xsd:annotation>
 				<xsd:complexType>
@@ -297,13 +331,15 @@
 					<xsd:attribute name="decider" type="xsd:string" use="required">
 						<xsd:annotation>
 							<xsd:documentation>
-								The decider is a reference to a JobExecutionDecider that can produce a status to base
+								The decider is a reference to a
+								JobExecutionDecider that can produce a status to base
 								the next
 								transition on.
 							</xsd:documentation>
 							<xsd:appinfo>
 								<tool:annotation kind="ref">
-									<tool:expected-type type="org.springframework.batch.core.job.flow.JobExecutionDecider" />
+									<tool:expected-type
+										type="org.springframework.batch.core.job.flow.JobExecutionDecider" />
 								</tool:annotation>
 							</xsd:appinfo>
 						</xsd:annotation>
@@ -315,9 +351,12 @@
 
 	<xsd:complexType name="taskletType">
 		<xsd:all>
-			<xsd:element name="chunk" type="chunkTaskletType" minOccurs="0" maxOccurs="1"/>
-			<xsd:element name="transaction-attributes" type="transaction-attributesType" minOccurs="0" maxOccurs="1"/>
-			<xsd:element name="no-rollback-exception-classes" minOccurs="0" maxOccurs="1">
+			<xsd:element name="chunk" type="chunkTaskletType"
+				minOccurs="0" maxOccurs="1" />
+			<xsd:element name="transaction-attributes" type="transaction-attributesType"
+				minOccurs="0" maxOccurs="1" />
+			<xsd:element name="no-rollback-exception-classes"
+				minOccurs="0" maxOccurs="1">
 				<xsd:annotation>
 					<xsd:documentation><![CDATA[
 					List of exception classes that should not cause rollback if possible.  This list
@@ -326,20 +365,24 @@
 					</xsd:documentation>
 				</xsd:annotation>
 				<xsd:complexType>
-					<xsd:group ref="includeElementGroup" minOccurs="0" maxOccurs="unbounded"/>
+					<xsd:group ref="includeElementGroup" minOccurs="0"
+						maxOccurs="unbounded" />
 					<xsd:attributeGroup ref="mergeAttribute" />
 				</xsd:complexType>
 			</xsd:element>
-			<xsd:element name="listeners" type="stepListenersType" minOccurs="0" maxOccurs="1"/>
+			<xsd:element name="listeners" type="stepListenersType"
+				minOccurs="0" maxOccurs="1" />
 		</xsd:all>
 		<xsd:attribute name="ref" type="xsd:string" use="optional">
 			<xsd:annotation>
 				<xsd:documentation>
-				The tasklet is a reference to another bean definition that implements the Tasklet interface.
+					The tasklet is a reference to another bean definition that implements
+					the Tasklet interface.
 				</xsd:documentation>
 				<xsd:appinfo>
 					<tool:annotation kind="ref">
-						<tool:expected-type type="org.springframework.batch.core.step.tasklet.Tasklet"/>
+						<tool:expected-type
+							type="org.springframework.batch.core.step.tasklet.Tasklet" />
 					</tool:annotation>
 				</xsd:appinfo>
 			</xsd:annotation>
@@ -351,7 +394,8 @@
 				]]></xsd:documentation>
 			</xsd:annotation>
 		</xsd:attribute>
-		<xsd:attribute name="allow-start-if-complete" type="xsd:string" use="optional">
+		<xsd:attribute name="allow-start-if-complete" type="xsd:string"
+			use="optional">
 			<xsd:annotation>
 				<xsd:documentation><![CDATA[
 				Set to true to allow a step to be started even if it is already complete.
@@ -374,7 +418,8 @@
 				</xsd:appinfo>
 			</xsd:annotation>
 		</xsd:attribute>
-		<xsd:attribute name="task-executor" type="xsd:string" use="optional">
+		<xsd:attribute name="task-executor" type="xsd:string"
+			use="optional">
 			<xsd:annotation>
 				<xsd:documentation source="java:org.springframework.core.task.TaskExecutor"><![CDATA[
 				The task executor responsible for executing the task.
@@ -386,7 +431,8 @@
 				</xsd:appinfo>
 			</xsd:annotation>
 		</xsd:attribute>
-		<xsd:attribute name="throttle-limit" type="xsd:string" use="optional">
+		<xsd:attribute name="throttle-limit" type="xsd:string"
+			use="optional">
 			<xsd:annotation>
 				<xsd:documentation><![CDATA[
 				This limits the number of tasks queued for concurrent 
@@ -400,7 +446,8 @@
 	<xsd:complexType name="transaction-attributesType">
 		<xsd:attribute name="propagation">
 			<xsd:annotation>
-				<xsd:documentation source="java:org.springframework.transaction.annotation.Propagation"><![CDATA[
+				<xsd:documentation
+					source="java:org.springframework.transaction.annotation.Propagation"><![CDATA[
 				The transaction propagation behavior.
 				]]></xsd:documentation>
 			</xsd:annotation>
@@ -418,7 +465,8 @@
 		</xsd:attribute>
 		<xsd:attribute name="isolation" type="isolationType">
 			<xsd:annotation>
-				<xsd:documentation source="java:org.springframework.transaction.annotation.Isolation"><![CDATA[
+				<xsd:documentation
+					source="java:org.springframework.transaction.annotation.Isolation"><![CDATA[
 				The transaction isolation level.
 				]]></xsd:documentation>
 			</xsd:annotation>
@@ -444,8 +492,8 @@
 
 	<xsd:group name="beanElementGroup">
 		<xsd:choice>
-			<xsd:element ref="beans:bean"/>
-			<xsd:element ref="beans:ref"/>
+			<xsd:element ref="beans:bean" />
+			<xsd:element ref="beans:ref" />
 		</xsd:choice>
 	</xsd:group>
 
@@ -459,8 +507,9 @@
 					</xsd:documentation>
 				</xsd:annotation>
 				<xsd:complexType>
-					<xsd:group ref="beanElementGroup" minOccurs="0" maxOccurs="1"/>
-					<xsd:attributeGroup ref="adapterMethodAttribute"/>
+					<xsd:group ref="beanElementGroup" minOccurs="0"
+						maxOccurs="1" />
+					<xsd:attributeGroup ref="adapterMethodAttribute" />
 				</xsd:complexType>
 			</xsd:element>
 			<xsd:element name="processor" minOccurs="0" maxOccurs="1">
@@ -471,8 +520,9 @@
 					</xsd:documentation>
 				</xsd:annotation>
 				<xsd:complexType>
-					<xsd:group ref="beanElementGroup" minOccurs="0" maxOccurs="1"/>
-					<xsd:attributeGroup ref="adapterMethodAttribute"/>
+					<xsd:group ref="beanElementGroup" minOccurs="0"
+						maxOccurs="1" />
+					<xsd:attributeGroup ref="adapterMethodAttribute" />
 				</xsd:complexType>
 			</xsd:element>
 			<xsd:element name="writer" minOccurs="0" maxOccurs="1">
@@ -483,11 +533,13 @@
 					</xsd:documentation>
 				</xsd:annotation>
 				<xsd:complexType>
-					<xsd:group ref="beanElementGroup" minOccurs="0" maxOccurs="1"/>
-					<xsd:attributeGroup ref="adapterMethodAttribute"/>
+					<xsd:group ref="beanElementGroup" minOccurs="0"
+						maxOccurs="1" />
+					<xsd:attributeGroup ref="adapterMethodAttribute" />
 				</xsd:complexType>
 			</xsd:element>
-			<xsd:element name="retry-listeners" minOccurs="0" maxOccurs="1">
+			<xsd:element name="retry-listeners" minOccurs="0"
+				maxOccurs="1">
 				<xsd:annotation>
 					<xsd:documentation><![CDATA[
 					List of all listeners for the step definition
@@ -496,7 +548,8 @@
 				</xsd:annotation>
 				<xsd:complexType>
 					<xsd:sequence>
-						<xsd:element name="listener" type="listenerType" minOccurs="0" maxOccurs="unbounded" />
+						<xsd:element name="listener" type="listenerType"
+							minOccurs="0" maxOccurs="unbounded" />
 					</xsd:sequence>
 					<xsd:attributeGroup ref="mergeAttribute" />
 				</xsd:complexType>
@@ -520,7 +573,8 @@
 										</xsd:documentation>
 										<xsd:appinfo>
 											<tool:annotation kind="ref" />
-											<tool:expected-type type="org.springframework.batch.item.ItemStream" />
+											<tool:expected-type
+												type="org.springframework.batch.item.ItemStream" />
 										</xsd:appinfo>
 									</xsd:annotation>
 								</xsd:attribute>
@@ -530,7 +584,8 @@
 					<xsd:attributeGroup ref="mergeAttribute" />
 				</xsd:complexType>
 			</xsd:element>
-			<xsd:element name="skippable-exception-classes" minOccurs="0" maxOccurs="1">
+			<xsd:element name="skippable-exception-classes"
+				minOccurs="0" maxOccurs="1">
 				<xsd:annotation>
 					<xsd:documentation><![CDATA[
 					List of exception classes that are skippable.  
@@ -540,11 +595,13 @@
 					</xsd:documentation>
 				</xsd:annotation>
 				<xsd:complexType>
-					<xsd:group ref="includeExcludeElementGroup" minOccurs="0" maxOccurs="unbounded"/>
+					<xsd:group ref="includeExcludeElementGroup" minOccurs="0"
+						maxOccurs="unbounded" />
 					<xsd:attributeGroup ref="mergeAttribute" />
 				</xsd:complexType>
 			</xsd:element>
-			<xsd:element name="retryable-exception-classes" minOccurs="0" maxOccurs="1">
+			<xsd:element name="retryable-exception-classes"
+				minOccurs="0" maxOccurs="1">
 				<xsd:annotation>
 					<xsd:documentation><![CDATA[
 					List of exception classes that are retryable.
@@ -552,12 +609,14 @@
 					</xsd:documentation>
 				</xsd:annotation>
 				<xsd:complexType>
-					<xsd:group ref="includeElementGroup" minOccurs="0" maxOccurs="unbounded"/>
+					<xsd:group ref="includeElementGroup" minOccurs="0"
+						maxOccurs="unbounded" />
 					<xsd:attributeGroup ref="mergeAttribute" />
 				</xsd:complexType>
 			</xsd:element>
 		</xsd:all>
-		<xsd:attribute name="commit-interval" type="xsd:string" use="optional">
+		<xsd:attribute name="commit-interval" type="xsd:string"
+			use="optional">
 			<xsd:annotation>
 				<xsd:documentation><![CDATA[
 				The number of items that will be processed before commit is called for the transaction.  
@@ -612,14 +671,16 @@
 				]]></xsd:documentation>
 			</xsd:annotation>
 		</xsd:attribute>
-		<xsd:attribute name="cache-capacity" type="xsd:string" use="optional">
+		<xsd:attribute name="cache-capacity" type="xsd:string"
+			use="optional">
 			<xsd:annotation>
 				<xsd:documentation><![CDATA[
 				The capacity of the cache in the retry policy.
 				]]></xsd:documentation>
 			</xsd:annotation>
 		</xsd:attribute>
-		<xsd:attribute name="reader-transactional-queue" type="xsd:string" use="optional">
+		<xsd:attribute name="reader-transactional-queue" type="xsd:string"
+			use="optional">
 			<xsd:annotation>
 				<xsd:documentation><![CDATA[
 				Whether the reader is a transactional queue. If it is then items read should not be cached 
@@ -627,16 +688,19 @@
 				]]></xsd:documentation>
 			</xsd:annotation>
 		</xsd:attribute>
-		<xsd:attribute name="chunk-completion-policy" type="xsd:string" use="optional">
+		<xsd:attribute name="chunk-completion-policy" type="xsd:string"
+			use="optional">
 			<xsd:annotation>
-				<xsd:documentation source="java:org.springframework.batch.repeat.CompletionPolicy"><![CDATA[
+				<xsd:documentation
+					source="java:org.springframework.batch.repeat.CompletionPolicy"><![CDATA[
 				A transaction will be committed when this policy decides to
 				complete. Defaults to a SimpleCompletionPolicy with chunk size
 				equal to the commit-interval attribute.
 				]]></xsd:documentation>
 				<xsd:appinfo>
 					<tool:annotation kind="ref">
-						<tool:expected-type type="java:org.springframework.batch.repeat.CompletionPolicy" />
+						<tool:expected-type
+							type="java:org.springframework.batch.repeat.CompletionPolicy" />
 					</tool:annotation>
 				</xsd:appinfo>
 			</xsd:annotation>
@@ -679,7 +743,7 @@
 					</xsd:documentation>
 				</xsd:annotation>
 				<xsd:complexType>
-					<xsd:attributeGroup ref="classAttribute"/>
+					<xsd:attributeGroup ref="classAttribute" />
 				</xsd:complexType>
 			</xsd:element>
 		</xsd:choice>
@@ -687,28 +751,30 @@
 
 	<xsd:group name="includeExcludeElementGroup">
 		<xsd:choice>
-			<xsd:group ref="includeElementGroup"/>
+			<xsd:group ref="includeElementGroup" />
 			<xsd:element name="exclude">
 				<xsd:annotation>
 					<xsd:documentation>
-						Classify an exception as "excluded" from the set.
+						Classify an exception as "excluded" from the
+						set.
 					</xsd:documentation>
 				</xsd:annotation>
 				<xsd:complexType>
-					<xsd:attributeGroup ref="classAttribute"/>
+					<xsd:attributeGroup ref="classAttribute" />
 				</xsd:complexType>
 			</xsd:element>
 		</xsd:choice>
 	</xsd:group>
 
 	<xsd:complexType name="listenerType">
-		<xsd:group ref="beanElementGroup" minOccurs="0" maxOccurs="1"/>
+		<xsd:group ref="beanElementGroup" minOccurs="0" maxOccurs="1" />
 		<xsd:attribute name="ref" type="xsd:string">
 			<xsd:annotation>
 				<xsd:documentation>
 					A reference to a listener, a POJO with a
 					listener-annotated method, or a POJO with
-					a method referenced by a *-method attribute.
+					a method referenced by a
+					*-method attribute.
 				</xsd:documentation>
 				<xsd:appinfo>
 					<tool:annotation kind="ref" />
@@ -757,7 +823,8 @@
 			</xsd:documentation>
 		</xsd:annotation>
 		<xsd:sequence>
-			<xsd:element name="listener" type="stepListenerType" minOccurs="0" maxOccurs="unbounded" />
+			<xsd:element name="listener" type="stepListenerType"
+				minOccurs="0" maxOccurs="unbounded" />
 		</xsd:sequence>
 		<xsd:attributeGroup ref="mergeAttribute" />
 	</xsd:complexType>
@@ -768,7 +835,8 @@
 				<xsd:annotation>
 					<xsd:documentation>
 						Defines a transition from this step to the
-						next one depending on the value of the exit
+						next
+						one depending on the value of the exit
 						status.
 					</xsd:documentation>
 				</xsd:annotation>
@@ -777,85 +845,107 @@
 						<xsd:annotation>
 							<xsd:documentation>A pattern to match against the exit status
 								code. Use * and ? as wildcard characters. When a
-								step finishes the most
-								specific match will be chosen to select the next step. Hint:
+								step finishes
+								the most
+								specific match will be chosen to select the next step.
+								Hint:
 								always include a default
-								transition with on=&quot;*&quot;.</xsd:documentation>
-						</xsd:annotation></xsd:attribute>
-					<xsd:attribute name="to" type="xsd:string" use="required" >
+								transition with on=&quot;*&quot;.
+							</xsd:documentation>
+						</xsd:annotation>
+					</xsd:attribute>
+					<xsd:attribute name="to" type="xsd:string" use="required">
 						<xsd:annotation>
 							<xsd:documentation>
-								The name of the step to go to next.  Must resolve to one of the other steps in this job.
+								The name of the step to go to next. Must
+								resolve to one of the other steps in this job.
 							</xsd:documentation>
 						</xsd:annotation>
 					</xsd:attribute>
 				</xsd:complexType>
-			</xsd:element>		
+			</xsd:element>
 			<xsd:element name="stop">
 				<xsd:annotation>
 					<xsd:documentation>
-						Declares job should be stop at this point and provides pointer where execution should continue when
-						the job is restarted.
+						Declares job should be stop at this point and
+						provides pointer where execution should continue when
+						the job is
+						restarted.
 					</xsd:documentation>
 				</xsd:annotation>
 				<xsd:complexType>
-					<xsd:attribute name="on" type="xsd:string" use="required" >
+					<xsd:attribute name="on" type="xsd:string" use="required">
 						<xsd:annotation>
-							<xsd:documentation>A pattern to match against the exit status code.  Use * and ? as wildcard characters. 
-							When a step finishes the most specific match will be chosen to select the next step.</xsd:documentation>
-						</xsd:annotation></xsd:attribute>
-					<xsd:attribute name="restart" type="xsd:string" use="required" >
-						<xsd:annotation>
-							<xsd:documentation>The name of the step to start on when the stopped job is restarted.  
-							Must resolve to one of the other steps in this job.</xsd:documentation>
+							<xsd:documentation>A pattern to match against the exit status
+								code. Use * and ? as wildcard characters.
+								When a step finishes the most specific match will be chosen to
+								select the next step.</xsd:documentation>
 						</xsd:annotation>
 					</xsd:attribute>
-				</xsd:complexType>		
-			</xsd:element>		
+					<xsd:attribute name="restart" type="xsd:string" use="required">
+						<xsd:annotation>
+							<xsd:documentation>The name of the step to start on when the
+								stopped job is restarted.
+								Must resolve to one of the other steps in this job.
+							</xsd:documentation>
+						</xsd:annotation>
+					</xsd:attribute>
+				</xsd:complexType>
+			</xsd:element>
 			<xsd:element name="end">
 				<xsd:annotation>
 					<xsd:documentation>
-						Declares job should end at this point, without the possibility of restart.  
-						BatchStatus will be COMPLETED.  ExitStatus is configurable.
+						Declares job should end at this point, without
+						the possibility of restart.
+						BatchStatus will be COMPLETED. ExitStatus is configurable.
 					</xsd:documentation>
 				</xsd:annotation>
 				<xsd:complexType>
-					<xsd:attribute name="on" type="xsd:string" use="required" >
+					<xsd:attribute name="on" type="xsd:string" use="required">
 						<xsd:annotation>
-							<xsd:documentation>A pattern to match against the exit status code.  Use * and ? as wildcard characters. 
-							When a step finishes the most specific match will be chosen to select the next step.</xsd:documentation>
+							<xsd:documentation>A pattern to match against the exit status
+								code. Use * and ? as wildcard characters.
+								When a step finishes the most specific match will be chosen to
+								select the next step.</xsd:documentation>
 						</xsd:annotation>
 					</xsd:attribute>
-					<xsd:attribute name="exit-code" use="optional" type="xsd:string" default="COMPLETED">
+					<xsd:attribute name="exit-code" use="optional" type="xsd:string"
+						default="COMPLETED">
 						<xsd:annotation>
-							<xsd:documentation>The exit code value to end on, defaults to COMPLETED.</xsd:documentation>
+							<xsd:documentation>The exit code value to end on, defaults to
+								COMPLETED.</xsd:documentation>
 						</xsd:annotation>
 					</xsd:attribute>
-				</xsd:complexType>		
-			</xsd:element>			
+				</xsd:complexType>
+			</xsd:element>
 			<xsd:element name="fail">
 				<xsd:annotation>
 					<xsd:documentation>
-						Declares job should fail at this point.  BatchStatus will be FAILED.  ExitStatus is configurable.
+						Declares job should fail at this point.
+						BatchStatus will be FAILED. ExitStatus is configurable.
 					</xsd:documentation>
 				</xsd:annotation>
 				<xsd:complexType>
-					<xsd:attribute name="on" type="xsd:string" use="required" >
+					<xsd:attribute name="on" type="xsd:string" use="required">
 						<xsd:annotation>
-							<xsd:documentation>A pattern to match against the exit status code.  Use * and ? as wildcard characters. 
-							When a step finishes the most specific match will be chosen to select the next step.</xsd:documentation>
+							<xsd:documentation>A pattern to match against the exit status
+								code. Use * and ? as wildcard characters.
+								When a step finishes the most specific match will be chosen to
+								select the next step.</xsd:documentation>
 						</xsd:annotation>
 					</xsd:attribute>
-					<xsd:attribute name="exit-code" use="optional" type="xsd:string" default="FAILED">
+					<xsd:attribute name="exit-code" use="optional" type="xsd:string"
+						default="FAILED">
 						<xsd:annotation>
-							<xsd:documentation>The exit code value to end on, defaults to FAILED.</xsd:documentation>
+							<xsd:documentation>The exit code value to end on, defaults to
+								FAILED.</xsd:documentation>
 						</xsd:annotation>
 					</xsd:attribute>
-				</xsd:complexType>		
-			</xsd:element>			
+				</xsd:complexType>
+			</xsd:element>
 		</xsd:choice>
 	</xsd:group>
-		
+
 	<xsd:attributeGroup name="jobRepositoryAttribute">
 		<xsd:attribute name="job-repository" type="xsd:string">
 			<xsd:annotation>
@@ -879,10 +969,11 @@
 		<xsd:attribute name="parent" type="xsd:string" use="optional">
 			<xsd:annotation>
 				<xsd:documentation>
-					The name of the parent bean from which the configuration should inherit.
+					The name of the parent bean from which the
+					configuration should inherit.
 				</xsd:documentation>
 				<xsd:appinfo>
-					<tool:annotation kind="ref"/>
+					<tool:annotation kind="ref" />
 				</xsd:appinfo>
 			</xsd:annotation>
 		</xsd:attribute>
@@ -892,11 +983,15 @@
 		<xsd:attribute name="abstract" type="xsd:boolean" use="optional">
 			<xsd:annotation>
 				<xsd:documentation>
-					Is this bean "abstract", that is, not meant to be instantiated itself
-					but rather just serving as parent for concrete child bean definitions?
-					The default is "false". Specify "true" to tell the bean factory to not
-					try to instantiate that particular bean in any case.
-				
+					Is this bean "abstract", that is, not meant to be
+					instantiated itself
+					but rather just serving as parent for concrete
+					child bean definitions?
+					The default is "false". Specify "true" to
+					tell the bean factory to not
+					try to instantiate that particular bean
+					in any case.
+
 					Note: This attribute will not be inherited by child bean definitions.
 					Hence, it needs to be specified per abstract bean definition.
 				</xsd:documentation>
@@ -908,24 +1003,27 @@
 		<xsd:attribute name="merge" type="xsd:boolean" use="optional">
 			<xsd:annotation>
 				<xsd:documentation>
-					Should this list be merged with the corresponding list provided 
-					by the parent?  If not, it will overwrite the parent list.
+					Should this list be merged with the corresponding
+					list provided
+					by the parent? If not, it will overwrite the parent list.
 				</xsd:documentation>
 			</xsd:annotation>
 		</xsd:attribute>
 	</xsd:attributeGroup>
 
 	<xsd:attributeGroup name="adapterMethodAttribute">
-		<xsd:attribute name="adapter-method" type="xsd:string" use="optional">
+		<xsd:attribute name="adapter-method" type="xsd:string"
+			use="optional">
 			<xsd:annotation>
 				<xsd:documentation>
-					This attribute indicates the method from the class that should 
+					This attribute indicates the method from the
+					class that should
 					be used to dynamically create a proxy.
 				</xsd:documentation>
 			</xsd:annotation>
 		</xsd:attribute>
 	</xsd:attributeGroup>
-	
+
 	<xsd:element name="description">
 		<xsd:annotation>
 			<xsd:documentation><![CDATA[
@@ -934,7 +1032,7 @@
 			]]></xsd:documentation>
 		</xsd:annotation>
 		<xsd:complexType mixed="true">
-			<xsd:choice minOccurs="0" maxOccurs="unbounded"/>
+			<xsd:choice minOccurs="0" maxOccurs="unbounded" />
 		</xsd:complexType>
 	</xsd:element>
 

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

@@ -20,6 +20,7 @@ import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
 
 import org.junit.BeforeClass;
@@ -28,6 +29,7 @@ import org.springframework.aop.framework.Advised;
 import org.springframework.batch.core.Job;
 import org.springframework.batch.core.JobExecutionListener;
 import org.springframework.batch.core.job.AbstractJob;
+import org.springframework.batch.core.job.DefaultJobParametersValidator;
 import org.springframework.batch.core.listener.JobExecutionListenerSupport;
 import org.springframework.batch.core.repository.JobRepository;
 import org.springframework.batch.core.repository.support.SimpleJobRepository;
@@ -182,6 +184,18 @@ public class JobParserTests {
 		}
 	}
 
+	@Test
+	public void testParametersValidator() {
+		ApplicationContext ctx = jobParserParentAttributeTestsCtx;
+		Job job = (Job) ctx.getBean("jobWithParametersValidator");
+		assertTrue(job instanceof AbstractJob);
+		Object validator = ReflectionTestUtils.getField(job, "jobParametersValidator");
+		assertTrue(validator instanceof DefaultJobParametersValidator);
+		@SuppressWarnings("unchecked")
+		Collection<String> keys = (Collection<String>) ReflectionTestUtils.getField(validator, "requiredKeys");
+		assertEquals(2, keys.size());
+	}
+
 	@Test
 	public void testListenerClearingJob() throws Exception {
 		assertEquals(0, getListeners("listenerClearingJob", jobParserParentAttributeTestsCtx).size());

spring-batch-core/src/test/java/org/springframework/batch/core/job/DefaultJobParametersValidatorTests.java

@@ -0,0 +1,43 @@
+package org.springframework.batch.core.job;
+
+import org.junit.Test;
+import org.springframework.batch.core.JobParameters;
+import org.springframework.batch.core.JobParametersBuilder;
+import org.springframework.batch.core.JobParametersInvalidException;
+
+public class DefaultJobParametersValidatorTests {
+
+	private DefaultJobParametersValidator validator = new DefaultJobParametersValidator();
+
+	@Test(expected = JobParametersInvalidException.class)
+	public void testValidateNull() throws Exception {
+		validator.validate(null);
+	}
+
+	@Test
+	public void testValidateRequiredValues() throws Exception {
+		validator.setRequiredKeys(new String[] { "name", "value" });
+		validator
+				.validate(new JobParametersBuilder().addString("name", "foo").addLong("value", 111L).toJobParameters());
+	}
+
+	@Test(expected = JobParametersInvalidException.class)
+	public void testValidateRequiredValuesMissing() throws Exception {
+		validator.setRequiredKeys(new String[] { "name", "value" });
+		validator.validate(new JobParameters());
+	}
+
+	@Test
+	public void testValidateOptionalValues() throws Exception {
+		validator.setOptionalKeys(new String[] { "name", "value" });
+		validator.validate(new JobParameters());
+	}
+
+	@Test(expected = IllegalStateException.class)
+	public void testOptionalValuesAlsoRequired() throws Exception {
+		validator.setOptionalKeys(new String[] { "name", "value" });
+		validator.setRequiredKeys(new String[] { "foo", "value" });
+		validator.afterPropertiesSet();
+	}
+
+}

spring-batch-core/src/test/java/org/springframework/batch/core/job/ExtendedAbstractJobTests.java

@@ -31,6 +31,7 @@ import org.springframework.batch.core.JobExecution;
 import org.springframework.batch.core.JobExecutionException;
 import org.springframework.batch.core.JobInterruptedException;
 import org.springframework.batch.core.JobParameters;
+import org.springframework.batch.core.JobParametersInvalidException;
 import org.springframework.batch.core.Step;
 import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.repository.JobRepository;
@@ -42,7 +43,7 @@ import org.springframework.batch.support.transaction.ResourcelessTransactionMana
  * @author Dave Syer
  * 
  */
-public class AbstractJobTests {
+public class ExtendedAbstractJobTests {
 
 	AbstractJob job = new StubJob("job");
 
@@ -109,6 +110,28 @@ public class AbstractJobTests {
 			assertTrue(e.getMessage().contains("JobRepository"));
 		}
 	}
+	
+	@Test(expected=JobParametersInvalidException.class)
+	public void testValidatorWithNullParameters() throws Exception {
+		job.validate(null);
+	}
+
+	@Test
+	public void testValidatorWithNotNullParameters() throws Exception {
+		job.validate(new JobParameters());
+		// Should be free of side effects
+	}
+
+	@Test(expected=JobParametersInvalidException.class)
+	public void testSetValidator() throws Exception {
+		job.setJobParametersValidator(new DefaultJobParametersValidator() {
+			@Override
+			public void validate(JobParameters parameters) throws JobParametersInvalidException {
+				throw new JobParametersInvalidException("Expected");
+			}
+		});
+		job.validate(new JobParameters());
+	}
 
 	/**
 	 * Runs the step and persists job execution context.

spring-batch-core/src/test/java/org/springframework/batch/core/job/JobSupport.java

@@ -21,7 +21,9 @@ import java.util.List;
 
 import org.springframework.batch.core.Job;
 import org.springframework.batch.core.JobExecution;
+import org.springframework.batch.core.JobParameters;
 import org.springframework.batch.core.JobParametersIncrementer;
+import org.springframework.batch.core.JobParametersInvalidException;
 import org.springframework.batch.core.Step;
 import org.springframework.batch.core.UnexpectedJobExecutionException;
 import org.springframework.beans.factory.BeanNameAware;
@@ -132,6 +134,13 @@ public class JobSupport implements BeanNameAware, Job {
 	public boolean isRestartable() {
 		return restartable;
 	}
+	
+	/**
+	 * @see Job#validate(JobParameters)
+	 */
+	public void validate(JobParameters parameters) throws JobParametersInvalidException {
+		
+	}
 
 	/*
 	 * (non-Javadoc)

spring-batch-core/src/test/java/org/springframework/batch/core/step/item/FaultTolerantExceptionClassesTests.java

@@ -17,10 +17,7 @@ import org.springframework.batch.core.Step;
 import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.job.SimpleJob;
 import org.springframework.batch.core.launch.JobLauncher;
-import org.springframework.batch.core.repository.JobExecutionAlreadyRunningException;
-import org.springframework.batch.core.repository.JobInstanceAlreadyCompleteException;
 import org.springframework.batch.core.repository.JobRepository;
-import org.springframework.batch.core.repository.JobRestartException;
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.ApplicationContext;
@@ -308,8 +305,7 @@ public class FaultTolerantExceptionClassesTests implements ApplicationContextAwa
 		assertEquals("[1, 1, 1, 1]", tasklet.getCommitted().toString());
 	}
 
-	private StepExecution launchStep(String stepName) throws JobExecutionAlreadyRunningException, JobRestartException,
-			JobInstanceAlreadyCompleteException {
+	private StepExecution launchStep(String stepName) throws Exception {
 		SimpleJob job = new SimpleJob();
 		job.setName("job");
 		job.setJobRepository(jobRepository);

spring-batch-core/src/test/resources/org/springframework/batch/core/configuration/xml/JobParserParentAttributeTests-context.xml

@@ -1,84 +1,117 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<beans:beans xmlns="http://www.springframework.org/schema/batch" xmlns:beans="http://www.springframework.org/schema/beans"
-	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+<beans:beans xmlns="http://www.springframework.org/schema/batch"
+	xmlns:beans="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 	xsi:schemaLocation="http://www.springframework.org/schema/batch http://www.springframework.org/schema/batch/spring-batch-2.1.xsd
 	http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
 
 	<beans:import resource="common-context.xml" />
 
 	<job id="job1" parent="baseJob">
-		<step id="s1"><tasklet ref="dummyTasklet"/></step>
-		
+		<step id="s1">
+			<tasklet ref="dummyTasklet" />
+		</step>
+
 		<listeners merge="true">
 			<listener>
-				<beans:bean class="org.springframework.batch.core.listener.JobExecutionListenerSupport"/>
+				<beans:bean
+					class="org.springframework.batch.core.listener.JobExecutionListenerSupport" />
 			</listener>
 		</listeners>
 	</job>
 
 	<job id="job2" parent="baseJob">
-		<step id="s2"><tasklet ref="dummyTasklet"/></step>
-		
+		<step id="s2">
+			<tasklet ref="dummyTasklet" />
+		</step>
+
 		<listeners>
 			<listener>
-				<beans:bean class="org.springframework.batch.core.listener.JobExecutionListenerSupport"/>
+				<beans:bean
+					class="org.springframework.batch.core.listener.JobExecutionListenerSupport" />
 			</listener>
 		</listeners>
 	</job>
 
 	<job id="job3" parent="baseJob3">
-		<step id="s3"><tasklet ref="dummyTasklet"/></step>
-		
+		<step id="s3">
+			<tasklet ref="dummyTasklet" />
+		</step>
+
 		<listeners merge="true">
-			<listener ref="listener1"/>
+			<listener ref="listener1" />
 		</listeners>
 	</job>
 
 	<job id="defaultRepoJob">
-		<step id="s4"><tasklet ref="dummyTasklet"/></step>
+		<step id="s4">
+			<tasklet ref="dummyTasklet" />
+		</step>
 	</job>
 
 	<job id="specifiedRepoJob" job-repository="dummyJobRepository">
-		<step id="s5"><tasklet ref="dummyTasklet"/></step>
+		<step id="s5">
+			<tasklet ref="dummyTasklet" />
+		</step>
 	</job>
 
 	<job id="inheritSpecifiedRepoJob" parent="baseSpecifiedRepoJob">
-		<step id="s6"><tasklet ref="dummyTasklet"/></step>
+		<step id="s6">
+			<tasklet ref="dummyTasklet" />
+		</step>
 	</job>
 
-	<job id="overrideInheritedRepoJob" parent="baseSpecifiedRepoJob" job-repository="jobRepository">
-		<step id="s7"><tasklet ref="dummyTasklet"/></step>
+	<job id="overrideInheritedRepoJob" parent="baseSpecifiedRepoJob"
+		job-repository="jobRepository">
+		<step id="s7">
+			<tasklet ref="dummyTasklet" />
+		</step>
 	</job>
 
-	<job id="baseSpecifiedRepoJob" abstract="true" job-repository="dummyJobRepository"/>
+	<job id="jobWithParametersValidator" parameters-validator="parametersValidator">
+		<step id="s8">
+			<tasklet ref="dummyTasklet" />
+		</step>
+	</job>
+	
+	<beans:bean id="parametersValidator"
+		class="org.springframework.batch.core.job.DefaultJobParametersValidator">
+		<beans:property name="requiredKeys" value="name,value"/>
+	</beans:bean>
+
+	<job id="baseSpecifiedRepoJob" abstract="true" job-repository="dummyJobRepository" />
 
 	<job id="baseJob" abstract="true">
 		<listeners>
 			<listener>
-				<beans:bean class="org.springframework.batch.core.configuration.xml.DummyAnnotationJobExecutionListener"/>
+				<beans:bean
+					class="org.springframework.batch.core.configuration.xml.DummyAnnotationJobExecutionListener" />
 			</listener>
 		</listeners>
 	</job>
 
 	<job-listener id="listener1">
-		<beans:bean class="org.springframework.batch.core.configuration.xml.DummyAnnotationJobExecutionListener"/>
+		<beans:bean
+			class="org.springframework.batch.core.configuration.xml.DummyAnnotationJobExecutionListener" />
 	</job-listener>
 
 	<beans:bean id="baseJob3" abstract="true">
 		<beans:property name="jobExecutionListeners">
 			<beans:list>
 				<job-listener>
-					<beans:bean class="org.springframework.batch.core.listener.JobExecutionListenerSupport"/>
+					<beans:bean
+						class="org.springframework.batch.core.listener.JobExecutionListenerSupport" />
 				</job-listener>
 			</beans:list>
 		</beans:property>
-	</beans:bean>
-
-	<beans:bean id="dummyJobRepository" class="org.springframework.batch.core.configuration.xml.DummyJobRepository"/>
+	</beans:bean>
+	<beans:bean id="dummyJobRepository"
+		class="org.springframework.batch.core.configuration.xml.DummyJobRepository" />
 
 	<job id="listenerClearingJob" parent="baseJob">
-		<step id="listenerClearingJobStep"><tasklet ref="dummyTasklet"/></step>
-		<listeners/>
+		<step id="listenerClearingJobStep">
+			<tasklet ref="dummyTasklet" />
+		</step>
+		<listeners />
 	</job>
-	
+
 </beans:beans>