Skip unnecessary attempt at executing Job

...that was already executed as part of the "local" set.

Also added some howto docs on executing Batch jobs.

See gh-382

docs/howto.md

@@ -912,6 +912,19 @@ scripts can act as "poor man's migrations" - inserts that fail mean
 that the data is already there, so there would be no need to prevent
 the application from running, for instance.
 
+### Spring Batch
+
+If you are using Spring Batch then it comes pre-packaged with SQL
+initialization scripts for most popular database platforms. Spring
+Boot will detect your database type, and execute those scripts by
+default, and in this case will switch the fail fast setting to false
+(errors are logged but do not prevent the application from
+starting). This is because the scripts are known to be reliable and
+generally do not contain bugs, so errors are ignorable, and ignoring
+them makes the scripts idempotent. You can switch off the
+initialization explicitly using
+`spring.batch.initializer.enabled=false`.
+
 ### Higher Level Migration Tools
 
 Spring Boot works fine with higher level migration tools
@@ -921,6 +934,31 @@ Flyway because it is easier on the eyes, and it isn't very common to
 need platform independence: usually only one or at most couple of
 platforms is needed.
 
+## Execute Spring Batch Jobs on Startup
+
+Spring Batch autoconfiguration is enabled by adding
+`@EnableBatchProcessing` (from Spring Batch) somewhere in your
+context.
+
+By default it executes *all* `Jobs` in the application context on
+startup (see
+[JobLauncherCommandLineRunner](https://github.com/spring-projects/spring-boot/blob/master/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/batch/JobLauncherCommandLineRunner.java)
+for details). You can narrow down to a specific job or jobs by
+specifying `spring.batch.job.names` (comma separated job name
+patterns). 
+
+If the application context includes a `JobRegistry` then
+the jobs in `spring.batch.job.names` are looked up in the regsitry
+instead of bein autowired from the context. This is a common pattern
+with more complex systems where multiple jobs are defined in child
+contexts and registered centrally.
+
+See
+[BatchAutoConfiguration](https://github.com/spring-projects/spring-boot/blob/master/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/batch/BatchAutoConfiguration.java)
+and
+[@EnableBatchProcessing](https://github.com/spring-projects/spring-batch/blob/master/spring-batch-core/src/main/java/org/springframework/batch/core/configuration/annotation/EnableBatchProcessing.java)
+for more details.
+
 <span id="discover.options"/>
 ## Discover Built-in Options for External Properties
 

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/batch/JobLauncherCommandLineRunner.java

@@ -23,17 +23,20 @@ import java.util.Properties;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-import org.springframework.batch.core.BatchStatus;
 import org.springframework.batch.core.Job;
 import org.springframework.batch.core.JobExecution;
 import org.springframework.batch.core.JobExecutionException;
 import org.springframework.batch.core.JobParameters;
+import org.springframework.batch.core.JobParametersInvalidException;
 import org.springframework.batch.core.configuration.JobRegistry;
 import org.springframework.batch.core.converter.DefaultJobParametersConverter;
 import org.springframework.batch.core.converter.JobParametersConverter;
 import org.springframework.batch.core.launch.JobLauncher;
 import org.springframework.batch.core.launch.NoSuchJobException;
+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.factory.annotation.Autowired;
 import org.springframework.boot.CommandLineRunner;
 import org.springframework.context.ApplicationEventPublisher;
@@ -103,14 +106,12 @@ public class JobLauncherCommandLineRunner implements CommandLineRunner,
 			for (String jobName : jobsToRun) {
 				try {
 					Job job = this.jobRegistry.getJob(jobName);
-					JobExecution previousExecution = jobRepository.getLastJobExecution(jobName, jobParameters);
-					if (previousExecution == null || previousExecution.getStatus() != BatchStatus.COMPLETED) {
-						JobExecution execution = this.jobLauncher.run(job, jobParameters);
-						if (this.publisher != null) {
-							this.publisher.publishEvent(new JobExecutionEvent(execution));
-						}
+					if (this.jobs.contains(job)) {
+						continue;
 					}
-				} catch (NoSuchJobException nsje) {
+					execute(job, jobParameters);
+				}
+				catch (NoSuchJobException nsje) {
 					logger.debug("No job found in registry for job name: " + jobName);
 					continue;
 				}
@@ -118,6 +119,20 @@ public class JobLauncherCommandLineRunner implements CommandLineRunner,
 		}
 	}
 
+	protected void execute(Job job, JobParameters jobParameters)
+			throws JobExecutionAlreadyRunningException, JobRestartException,
+			JobInstanceAlreadyCompleteException, JobParametersInvalidException {
+		String jobName = job.getName();
+		JobExecution previousExecution = this.jobRepository.getLastJobExecution(jobName,
+				jobParameters);
+		if (previousExecution == null || previousExecution.getStatus().isUnsuccessful()) {
+			JobExecution execution = this.jobLauncher.run(job, jobParameters);
+			if (this.publisher != null) {
+				this.publisher.publishEvent(new JobExecutionEvent(execution));
+			}
+		}
+	}
+
 	private void executeLocalJobs(JobParameters jobParameters)
 			throws JobExecutionException {
 		for (Job job : this.jobs) {
@@ -128,10 +143,7 @@ public class JobLauncherCommandLineRunner implements CommandLineRunner,
 					continue;
 				}
 			}
-			JobExecution execution = this.jobLauncher.run(job, jobParameters);
-			if (this.publisher != null) {
-				this.publisher.publishEvent(new JobExecutionEvent(execution));
-			}
+			execute(job, jobParameters);
 		}
 	}
 

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/batch/BatchAutoConfigurationTests.java

@@ -120,14 +120,15 @@ public class BatchAutoConfigurationTests {
 		this.context = new AnnotationConfigApplicationContext();
 		EnvironmentTestUtils.addEnvironment(this.context,
 				"spring.batch.job.names:discreteRegisteredJob");
-		this.context.register(NamedJobConfigurationWithRegisteredJob.class, BatchAutoConfiguration.class,
-				EmbeddedDataSourceConfiguration.class,
+		this.context.register(NamedJobConfigurationWithRegisteredJob.class,
+				BatchAutoConfiguration.class, EmbeddedDataSourceConfiguration.class,
 				PropertyPlaceholderAutoConfiguration.class);
 		this.context.refresh();
+		JobRepository repository = this.context.getBean(JobRepository.class);
 		assertNotNull(this.context.getBean(JobLauncher.class));
 		this.context.getBean(JobLauncherCommandLineRunner.class).run();
-		assertNotNull(this.context.getBean(JobRepository.class).getLastJobExecution(
-				"discreteRegisteredJob", new JobParameters()));
+		assertNotNull(repository.getLastJobExecution("discreteRegisteredJob",
+				new JobParameters()));
 	}
 
 	@Test
@@ -135,8 +136,8 @@ public class BatchAutoConfigurationTests {
 		this.context = new AnnotationConfigApplicationContext();
 		EnvironmentTestUtils.addEnvironment(this.context,
 				"spring.batch.job.names:discreteLocalJob");
-		this.context.register(NamedJobConfigurationWithLocalJob.class, BatchAutoConfiguration.class,
-				EmbeddedDataSourceConfiguration.class,
+		this.context.register(NamedJobConfigurationWithLocalJob.class,
+				BatchAutoConfiguration.class, EmbeddedDataSourceConfiguration.class,
 				PropertyPlaceholderAutoConfiguration.class);
 		this.context.refresh();
 		assertNotNull(this.context.getBean(JobLauncher.class));
@@ -213,7 +214,7 @@ public class BatchAutoConfigurationTests {
 		@Bean
 		public JobRegistryBeanPostProcessor registryProcessor() {
 			JobRegistryBeanPostProcessor processor = new JobRegistryBeanPostProcessor();
-			processor.setJobRegistry(jobRegistry);
+			processor.setJobRegistry(this.jobRegistry);
 			return processor;
 		}