Propagate step exit description from FlowJob to JobExecution

Issue: gh-3740

When a step inside a FlowJob fails, the StepExecution's exit status
already contains the failure description (typically the stack trace
recorded by AbstractStep). However, JobFlowExecutor.executeStep only
returned the exit code, and the final JobFlowExecutor.updateJobExecutionStatus
combined the executor's tracked ExitStatus (which had no description)
with an ExitStatus built from the FlowExecutionStatus name. As a result
the step's exit description was discarded and the JobExecution ended
with an empty exit description, in contrast to SimpleJob which assigns
stepExecution.getExitStatus() directly.

Accumulate the step's exit description into the executor's tracked
ExitStatus in executeStep so it survives the final
updateJobExecutionStatus call. ExitStatus.addExitDescription already
deduplicates equal descriptions and concatenates distinct ones with a
semicolon, so multiple step failures along a flow path are preserved
without duplication.

Signed-off-by: Seonwoo Jung <laborlawseon@kap.kr>

Author: seonwooj0810

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

@@ -82,6 +82,12 @@ public String executeStep(Step step)
 			stepExecution.getExecutionContext().put("batch.restart", true);
 		}
 
+		// Preserve the step's exit description (e.g., the stack trace recorded by
+		// AbstractStep when a step fails) so it survives the flow's final
+		// updateJobExecutionStatus() call, which only carries the FlowExecutionStatus
+		// name and would otherwise discard it.
+		exitStatus = exitStatus.addExitDescription(stepExecution.getExitStatus().getExitDescription());
+
 		return stepExecution.getExitStatus().getExitCode();
 	}
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2023 the original author or authors.
+ * Copyright 2010-2026 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,6 +16,7 @@
 package org.springframework.batch.core.job.flow;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -91,6 +92,35 @@ void testStepFailure() throws Exception {
 		assertEquals(BatchStatus.FAILED, execution.getStatus());
 	}
 
+	@Test // gh-3740
+	void testStepFailureExitDescriptionPropagatedToJobExecution() throws Exception {
+		final String failureDescription = "boom: simulated step failure";
+		SimpleFlow flow = new SimpleFlow("job");
+		List<StateTransition> transitions = new ArrayList<>();
+		StepState step = new StepState(new StepSupport("step") {
+			@Override
+			public void execute(StepExecution stepExecution)
+					throws JobInterruptedException, UnexpectedJobExecutionException {
+				stepExecution.setExitStatus(ExitStatus.FAILED.addExitDescription(failureDescription));
+				stepExecution.setStatus(BatchStatus.FAILED);
+			}
+		});
+		transitions.add(StateTransition.createStateTransition(step, ExitStatus.FAILED.getExitCode(), "end0"));
+		transitions.add(StateTransition.createStateTransition(step, ExitStatus.COMPLETED.getExitCode(), "end1"));
+		transitions.add(StateTransition.createEndStateTransition(new EndState(FlowExecutionStatus.FAILED, "end0")));
+		transitions.add(StateTransition.createEndStateTransition(new EndState(FlowExecutionStatus.COMPLETED, "end1")));
+		flow.setStateTransitions(transitions);
+		job.setFlow(flow);
+		job.afterPropertiesSet();
+		job.execute(execution);
+
+		assertEquals(BatchStatus.FAILED, execution.getStatus());
+		assertEquals(ExitStatus.FAILED.getExitCode(), execution.getExitStatus().getExitCode());
+		assertTrue(execution.getExitStatus().getExitDescription().contains(failureDescription),
+				"Expected JobExecution exit description to contain step failure description but was: '"
+						+ execution.getExitStatus().getExitDescription() + "'");
+	}
+
 	@Test
 	void testStepStatusUnknown() throws Exception {
 		SimpleFlow flow = new SimpleFlow("job");

spring-batch-integration/src/test/java/org/springframework/batch/integration/step/StepGatewayIntegrationTests.java

@@ -65,7 +65,7 @@ void testLaunchFailedJob() throws Exception {
 		JobExecution jobExecution = jobOperator.start(job,
 				new JobParametersBuilder().addLong("run.id", 2L).toJobParameters());
 		assertEquals(BatchStatus.FAILED, jobExecution.getStatus());
-		assertEquals(ExitStatus.FAILED, jobExecution.getExitStatus());
+		assertEquals(ExitStatus.FAILED.getExitCode(), jobExecution.getExitStatus().getExitCode());
 	}
 
 }