Add batch-5-to-6 module: Spring Batch 5.2 to 6.0 migration on Boot 3.5 to 4.1

Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01Gth99spB1CzQmBFofXmU4Z

batch-5-to-6/legacy/src/main/java/com/ankurm/batch/App.java

@@ -0,0 +1,14 @@
+package com.ankurm.batch;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.ConfigurableApplicationContext;
+
+@SpringBootApplication
+public class App {
+    public static void main(String[] args) {
+        ConfigurableApplicationContext ctx = SpringApplication.run(App.class, args);
+        ctx.getBean(JobRunner.class).run();
+        ctx.close();
+    }
+}

batch-5-to-6/legacy/src/main/java/com/ankurm/batch/BatchConfig.java

@@ -0,0 +1,55 @@
+package com.ankurm.batch;
+
+import java.util.List;
+import org.springframework.batch.core.ChunkListener;
+import org.springframework.batch.core.Job;
+import org.springframework.batch.core.Step;
+import org.springframework.batch.core.job.builder.JobBuilder;
+import org.springframework.batch.core.repository.JobRepository;
+import org.springframework.batch.core.scope.context.ChunkContext;
+import org.springframework.batch.core.step.builder.StepBuilder;
+import org.springframework.batch.item.ItemReader;
+import org.springframework.batch.item.ItemWriter;
+import org.springframework.batch.item.support.ListItemReader;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.transaction.PlatformTransactionManager;
+
+@Configuration
+public class BatchConfig {
+
+    @Bean
+    ItemReader<Integer> reader() {
+        return new ListItemReader<>(List.of(1, 2, 3, 4, 5, 6, 7));
+    }
+
+    @Bean
+    ItemWriter<String> writer() {
+        return chunk -> System.out.println("WRITE " + chunk.getItems());
+    }
+
+    @Bean
+    ChunkListener chunkListener() {
+        return new ChunkListener() {
+            @Override public void afterChunk(ChunkContext context) {
+                System.out.println("CHUNK DONE, read so far=" + context.getStepContext().getStepExecution().getReadCount());
+            }
+        };
+    }
+
+    @Bean
+    Step squareStep(JobRepository repo, PlatformTransactionManager tx, ChunkListener listener) {
+        return new StepBuilder("squareStep", repo)
+                .<Integer, String>chunk(3, tx)
+                .reader(reader())
+                .processor(i -> "sq" + (i * i))
+                .writer(writer())
+                .listener(listener)
+                .build();
+    }
+
+    @Bean
+    Job squareJob(JobRepository repo, Step squareStep) {
+        return new JobBuilder("squareJob", repo).start(squareStep).build();
+    }
+}

batch-5-to-6/legacy/src/main/java/com/ankurm/batch/JobRunner.java

@@ -0,0 +1,33 @@
+package com.ankurm.batch;
+
+import org.springframework.batch.core.BatchStatus;
+import org.springframework.batch.core.Job;
+import org.springframework.batch.core.JobExecution;
+import org.springframework.batch.core.JobParameters;
+import org.springframework.batch.core.JobParametersBuilder;
+import org.springframework.batch.core.explore.JobExplorer;
+import org.springframework.batch.core.launch.JobLauncher;
+import org.springframework.stereotype.Component;
+
+@Component
+public class JobRunner {
+    private final JobLauncher launcher;
+    private final JobExplorer explorer;
+    private final Job job;
+
+    public JobRunner(JobLauncher launcher, JobExplorer explorer, Job squareJob) {
+        this.launcher = launcher; this.explorer = explorer; this.job = squareJob;
+    }
+
+    public void run() {
+        try {
+            JobParameters params = new JobParametersBuilder().addLong("run.id", 1L).toJobParameters();
+            JobExecution exec = launcher.run(job, params);
+            System.out.println("STATUS " + exec.getStatus() + " exit=" + exec.getExitStatus().getExitCode());
+            System.out.println("INSTANCES " + explorer.getJobInstanceCount("squareJob"));
+            System.out.println("DONE " + (exec.getStatus() == BatchStatus.COMPLETED));
+        } catch (Exception e) {
+            throw new IllegalStateException(e);
+        }
+    }
+}

batch-5-to-6/legacy/src/main/resources/application.properties

@@ -0,0 +1,3 @@
+spring.batch.job.enabled=false
+spring.datasource.url=jdbc:h2:mem:legacy;DB_CLOSE_DELAY=-1
+spring.batch.jdbc.initialize-schema=always

batch-5-to-6/legacy/src/test/java/com/ankurm/batch/JobTest.java

@@ -0,0 +1,23 @@
+package com.ankurm.batch;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.batch.core.BatchStatus;
+import org.springframework.batch.core.JobExecution;
+import org.springframework.batch.test.JobLauncherTestUtils;
+import org.springframework.batch.test.context.SpringBatchTest;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+@SpringBatchTest
+class JobTest {
+    @Autowired JobLauncherTestUtils utils;
+
+    @Test
+    void jobCompletes() throws Exception {
+        JobExecution exec = utils.launchJob();
+        assertThat(exec.getStatus()).isEqualTo(BatchStatus.COMPLETED);
+    }
+}