Fix object graph deletion in SimpleJobRepository#deleteJobInstance

Before this commit, SimpleJobRepository#deleteJobInstance
was only deleting the given job instance and not the entire
object graph, which leads to data inconsistency (orphan job
executions and invalid foreign keys).

This commit fixes the contract and the implementation of the method
to delete the entire object graph.

Resolves #4250

Author: fmbenhassine

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2022 the original author or authors.
+ * Copyright 2006-2023 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.
@@ -244,7 +244,9 @@ default void deleteJobExecution(JobExecution jobExecution) {
 	}
 
 	/**
-	 * Delete the job instance.
+	 * Delete the job instance object graph (ie the job instance with all associated job
+	 * executions along with their respective object graphs as specified in
+	 * {@link #deleteJobExecution(JobExecution)}).
 	 * @param jobInstance the job instance to delete
 	 * @since 5.0
 	 */

spring-batch-core/src/main/java/org/springframework/batch/core/repository/dao/JobInstanceDao.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2022 the original author or authors.
+ * Copyright 2006-2023 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.
@@ -131,7 +131,8 @@ default JobInstance getLastJobInstance(String jobName) {
 	long getJobInstanceCount(@Nullable String jobName) throws NoSuchJobException;
 
 	/**
-	 * Delete the job instance.
+	 * Delete the job instance. This method is not expected to delete the associated job
+	 * executions. If this is needed, clients of this method should do that manually.
 	 * @param jobInstance the job instance to delete
 	 * @since 5.0
 	 */

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

@@ -328,6 +328,10 @@ public void deleteJobExecution(JobExecution jobExecution) {
 
 	@Override
 	public void deleteJobInstance(JobInstance jobInstance) {
+		List<JobExecution> jobExecutions = this.jobExecutionDao.findJobExecutions(jobInstance);
+		for (JobExecution jobExecution : jobExecutions) {
+			deleteJobExecution(jobExecution);
+		}
 		this.jobInstanceDao.deleteJobInstance(jobInstance);
 	}
 

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

@@ -366,4 +366,22 @@ void testDeleteJobExecution() {
 		verify(this.jobExecutionDao).deleteJobExecution(jobExecution);
 	}
 
+	@Test
+	void testDeleteJobInstance() {
+		// given
+		JobExecution jobExecution1 = mock(JobExecution.class);
+		JobExecution jobExecution2 = mock(JobExecution.class);
+		JobInstance jobInstance = mock(JobInstance.class);
+		when(this.jobExecutionDao.findJobExecutions(jobInstance))
+				.thenReturn(Arrays.asList(jobExecution1, jobExecution2));
+
+		// when
+		this.jobRepository.deleteJobInstance(jobInstance);
+
+		// then
+		verify(this.jobExecutionDao).deleteJobExecution(jobExecution1);
+		verify(this.jobExecutionDao).deleteJobExecution(jobExecution2);
+		verify(this.jobInstanceDao).deleteJobInstance(jobInstance);
+	}
+
 }