Fix NullPointerException when creating job executions for job instances without executions

Author: hpoettker

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

@@ -116,6 +116,10 @@ public JobExecution createJobExecution(String jobName, JobParameters jobParamete
 
 			List<JobExecution> executions = jobExecutionDao.findJobExecutions(jobInstance);
 
+			if (executions.isEmpty()) {
+				throw new IllegalStateException("Cannot find any job execution for job instance: " + jobInstance);
+			}
+
 			// check for running executions and find the last started
 			for (JobExecution execution : executions) {
 				if (execution.isRunning() || execution.isStopping()) {

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

@@ -27,6 +27,7 @@
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.Date;
 import java.util.List;
 
@@ -274,6 +275,14 @@ public void testCreateJobExecutionAlreadyComplete() throws Exception {
 		jobRepository.createJobExecution("foo", new JobParameters());
 	}
 
+	@Test(expected = IllegalStateException.class)
+	public void testCreateJobExecutionInstanceWithoutExecutions() throws Exception {
+		when(jobInstanceDao.getJobInstance("foo", new JobParameters())).thenReturn(jobInstance);
+		when(jobExecutionDao.findJobExecutions(jobInstance)).thenReturn(Collections.emptyList());
+
+		jobRepository.createJobExecution("foo", new JobParameters());
+	}
+
 	@Test
 	public void testGetStepExecutionCount() {
 		// Given