Add initial support for a resourceless job repository

Resolves #4679

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

@@ -0,0 +1,128 @@
+/*
+ * Copyright 2024 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.batch.core.repository.support;
+
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+
+import org.springframework.batch.core.JobExecution;
+import org.springframework.batch.core.JobInstance;
+import org.springframework.batch.core.JobParameters;
+import org.springframework.batch.core.StepExecution;
+import org.springframework.batch.core.repository.JobRepository;
+import org.springframework.batch.support.transaction.ResourcelessTransactionManager;
+
+/**
+ * A {@link JobRepository} implementation that does not use or store batch meta-data. It
+ * is intended for use-cases where restartability is not required and where the execution
+ * context is not involved in any way (like sharing data between steps through the
+ * execution context, or partitioned steps where partitions meta-data is shared between
+ * the manager and workers through the execution context, etc). <br/>
+ * This implementation holds a single job instance and a corresponding job execution that
+ * are suitable for one-time jobs executed in their own JVM. This job repository works
+ * with transactional steps as well as non-transactional steps (in which case, a
+ * {@link ResourcelessTransactionManager} can be used). <br/>
+ * This implementation is not thread-safe and should not be used in any concurrent
+ * environment.
+ *
+ * @since 5.2.0
+ * @author Mahmoud Ben Hassine
+ */
+public class ResourcelessJobRepository implements JobRepository {
+
+	private JobInstance jobInstance;
+
+	private JobExecution jobExecution;
+
+	@Override
+	public boolean isJobInstanceExists(String jobName, JobParameters jobParameters) {
+		return false;
+	}
+
+	@Override
+	public JobInstance createJobInstance(String jobName, JobParameters jobParameters) {
+		this.jobInstance = new JobInstance(1L, jobName);
+		return this.jobInstance;
+	}
+
+	@Override
+	public JobExecution createJobExecution(String jobName, JobParameters jobParameters) {
+		if (this.jobInstance == null) {
+			createJobInstance(jobName, jobParameters);
+		}
+		this.jobExecution = new JobExecution(this.jobInstance, 1L, jobParameters);
+		return this.jobExecution;
+	}
+
+	@Override
+	public void update(JobExecution jobExecution) {
+		jobExecution.setLastUpdated(LocalDateTime.now());
+		this.jobExecution = jobExecution;
+	}
+
+	@Override
+	public void add(StepExecution stepExecution) {
+		this.addAll(Collections.singletonList(stepExecution));
+	}
+
+	@Override
+	public void addAll(Collection<StepExecution> stepExecutions) {
+		this.jobExecution.addStepExecutions(new ArrayList<>(stepExecutions));
+	}
+
+	@Override
+	public void update(StepExecution stepExecution) {
+		stepExecution.setLastUpdated(LocalDateTime.now());
+		if (this.jobExecution.isStopping()) {
+			stepExecution.setTerminateOnly();
+		}
+	}
+
+	@Override
+	public void updateExecutionContext(StepExecution stepExecution) {
+		stepExecution.setLastUpdated(LocalDateTime.now());
+	}
+
+	@Override
+	public void updateExecutionContext(JobExecution jobExecution) {
+		jobExecution.setLastUpdated(LocalDateTime.now());
+	}
+
+	@Override
+	public StepExecution getLastStepExecution(JobInstance jobInstance, String stepName) {
+		return this.jobExecution.getStepExecutions()
+			.stream()
+			.filter(stepExecution -> stepExecution.getStepName().equals(stepName))
+			.findFirst()
+			.orElse(null);
+	}
+
+	@Override
+	public long getStepExecutionCount(JobInstance jobInstance, String stepName) {
+		return this.jobExecution.getStepExecutions()
+			.stream()
+			.filter(stepExecution -> stepExecution.getStepName().equals(stepName))
+			.count();
+	}
+
+	@Override
+	public JobExecution getLastJobExecution(String jobName, JobParameters jobParameters) {
+		return this.jobExecution;
+	}
+
+}

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

@@ -0,0 +1,90 @@
+/*
+ * Copyright 2024 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.batch.core.repository.support;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.batch.core.JobExecution;
+import org.springframework.batch.core.JobInstance;
+import org.springframework.batch.core.JobParameters;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+/**
+ * Test class for {@link ResourcelessJobRepository}.
+ *
+ * @author Mahmoud Ben Hassine
+ */
+class ResourcelessJobRepositoryTests {
+
+	private final ResourcelessJobRepository jobRepository = new ResourcelessJobRepository();
+
+	@Test
+	void isJobInstanceExists() {
+		assertFalse(this.jobRepository.isJobInstanceExists("job", new JobParameters()));
+	}
+
+	@Test
+	void createJobInstance() {
+		// given
+		String jobName = "job";
+		JobParameters jobParameters = new JobParameters();
+
+		// when
+		JobInstance jobInstance = this.jobRepository.createJobInstance(jobName, jobParameters);
+
+		// then
+		assertNotNull(jobInstance);
+		assertEquals(jobName, jobInstance.getJobName());
+		assertEquals(1L, jobInstance.getInstanceId());
+	}
+
+	@Test
+	void createJobExecution() {
+		// given
+		String jobName = "job";
+		JobParameters jobParameters = new JobParameters();
+
+		// when
+		JobExecution jobExecution = this.jobRepository.createJobExecution(jobName, jobParameters);
+
+		// then
+		assertNotNull(jobExecution);
+		assertEquals(1L, jobExecution.getId());
+		assertEquals(jobName, jobExecution.getJobInstance().getJobName());
+		assertEquals(1L, jobExecution.getJobInstance().getInstanceId());
+	}
+
+	@Test
+	void getLastJobExecution() {
+		// given
+		String jobName = "job";
+		JobParameters jobParameters = new JobParameters();
+		this.jobRepository.createJobExecution(jobName, jobParameters);
+
+		// when
+		JobExecution jobExecution = this.jobRepository.getLastJobExecution(jobName, jobParameters);
+
+		// then
+		assertNotNull(jobExecution);
+		assertEquals(1L, jobExecution.getId());
+		assertEquals(jobName, jobExecution.getJobInstance().getJobName());
+		assertEquals(1L, jobExecution.getJobInstance().getInstanceId());
+	}
+
+}