Improve error message when using ResourcelessJobRepository with partitioned steps

spring-batch-core/src/main/java/org/springframework/batch/core/partition/support/SimpleStepExecutionSplitter.java

@@ -33,6 +33,7 @@
 import org.springframework.batch.core.partition.Partitioner;
 import org.springframework.batch.core.partition.StepExecutionSplitter;
 import org.springframework.batch.core.repository.JobRepository;
+import org.springframework.batch.core.repository.support.ResourcelessJobRepository;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.util.Assert;
@@ -148,6 +149,12 @@ public String getStepName() {
 	@Override
 	public Set<StepExecution> split(StepExecution stepExecution, int gridSize) throws JobExecutionException {
 
+		if (jobRepository instanceof ResourcelessJobRepository) {
+			throw new JobExecutionException("ResourcelessJobRepository cannot be used with partitioned steps "
+					+ "as it does not support execution context. Please use a different JobRepository implementation "
+					+ "that supports batch meta-data storage for partitioned steps.");
+		}
+
 		JobExecution jobExecution = stepExecution.getJobExecution();
 
 		Map<String, ExecutionContext> contexts = getContexts(stepExecution, gridSize);

spring-batch-core/src/test/java/org/springframework/batch/core/partition/support/SimpleStepExecutionSplitterTests.java

@@ -36,6 +36,7 @@
 import org.springframework.batch.core.partition.Partitioner;
 import org.springframework.batch.core.repository.JobRepository;
 import org.springframework.batch.core.repository.support.JdbcJobRepositoryFactoryBean;
+import org.springframework.batch.core.repository.support.ResourcelessJobRepository;
 import org.springframework.batch.core.step.tasklet.TaskletStep;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.jdbc.support.JdbcTransactionManager;
@@ -44,6 +45,7 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 class SimpleStepExecutionSplitterTests {
@@ -219,6 +221,26 @@ void testAbandonedStatus() throws Exception {
 		}
 	}
 
+	@Test
+	void testResourcelessJobRepositoryThrowsException() throws Exception {
+		// Create a ResourcelessJobRepository for testing
+		ResourcelessJobRepository resourcelessRepo = new ResourcelessJobRepository();
+		JobExecution jobExecution = resourcelessRepo.createJobExecution("job", new JobParameters());
+		StepExecution stepExecution = jobExecution.createStepExecution("bar");
+
+		// Create splitter with ResourcelessJobRepository
+		SimpleStepExecutionSplitter splitter = new SimpleStepExecutionSplitter(resourcelessRepo, true, step.getName(),
+				new SimplePartitioner());
+
+		// Verify that attempting to split with ResourcelessJobRepository throws
+		// appropriate exception
+		JobExecutionException exception = assertThrows(JobExecutionException.class,
+				() -> splitter.split(stepExecution, 2));
+
+		assertTrue(exception.getMessage().contains("ResourcelessJobRepository cannot be used with partitioned steps"));
+		assertTrue(exception.getMessage().contains("does not support execution context"));
+	}
+
 	private StepExecution update(Set<StepExecution> split, StepExecution stepExecution, BatchStatus status)
 			throws Exception {
 		return update(split, stepExecution, status, true);