Avoid duplicated job execution when an execution is waiting to start

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

@@ -259,6 +259,14 @@ public StepExecution createStepExecution(String stepName) {
 		return stepExecution;
 	}
 
+	/**
+	 * Test if this {@link JobExecution} indicates that it is waiting to start.
+	 * @return true if the status is {@link BatchStatus#STARTING}.
+	 */
+	public boolean isStarting() {
+		return status == BatchStatus.STARTING;
+	}
+
 	/**
 	 * Test if this {@link JobExecution} indicates that it is running.
 	 * Note that this does not necessarily mean that it has been persisted.

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

@@ -123,7 +123,7 @@ public JobExecution createJobExecution(String jobName, JobParameters jobParamete
 
 			// check for running executions and find the last started
 			for (JobExecution execution : executions) {
-				if (execution.isRunning() || execution.isStopping()) {
+				if (execution.isStarting() || execution.isRunning() || execution.isStopping()) {
 					throw new JobExecutionAlreadyRunningException("A job execution for this job is already running: "
 							+ jobInstance);
 				}

spring-batch-core/src/test/java/org/springframework/batch/core/repository/support/SimpleJobRepositoryIntegrationTests.java

@@ -174,6 +174,25 @@ public void testSaveExecutionContext() throws Exception {
 		// assertEquals(ctx, retrievedJobExec.getExecutionContext());
 	}
 
+	/*
+	 * If JobExecution is waiting to start, exception will be thrown in attempt
+	 * to create new execution.
+	 */
+	@Transactional
+	@Test
+	public void testStartingJobRejectsAnotherJobExecution() throws Exception {
+		job.setRestartable(true);
+		JobExecution jobExecution = jobRepository.createJobExecution(job.getName(), jobParameters);
+
+		try {
+			jobRepository.createJobExecution(job.getName(), jobParameters);
+			fail();
+		}
+		catch (JobExecutionAlreadyRunningException e) {
+			// expected
+		}
+	}
+
 	/*
 	 * If JobExecution is already running, exception will be thrown in attempt
 	 * to create new execution.