My job which is made up of a chunkBasedStep doesnt run properly in my spring batch application

Question

I'm a bit new to Spring batch but I am really confused as to how I have not been able to run a job compeletely. In my Step, I've used chunk based step to work some logic that i want to execute.

This is my job config class. I want to read from an excel file and write to the console, what was read from the file. The job executes, even the step executes as it goes to the ItemReader and then into the itemWriter but it doesnt perform any action in the ItemWriter. Its so annonying as there isnt any error so I dont know what's going on.

@SpringBootApplication
@EnableBatchProcessing
public class JobConfig {
    private final JobBuilderFactory jobBuilderFactory;
    private final StepBuilderFactory stepBuilderFactory;

    public JobConfig(JobBuilderFactory jobBuilderFactory, StepBuilderFactory stepBuilderFactory) {
        this.jobBuilderFactory = jobBuilderFactory;
        this.stepBuilderFactory = stepBuilderFactory;
    }

// ItemReader to read from an xls Sheet and map to my Student class
    @Bean
    public ItemReader<Students> xlsItemReader() {
        PoiItemReader<Students> itemReader = new PoiItemReader<>();
        itemReader.setName("xlsItemReader");
        itemReader.setLinesToSkip(1);
        itemReader.setResource(new FileSystemResource("src/main/resources/ResumptionStatus.xls"));
        BeanWrapperRowMapper<Students> studentsRowMapper = new BeanWrapperRowMapper<>();
        studentsRowMapper.setTargetType(Students.class);
        itemReader.setRowMapper(studentsRowMapper);
        System.out.println("XLS READER!!!");
        return itemReader;
    }

// ItemWriter to print to the console.
@Bean
    public ItemWriter<? super Students> xlsItemWriter() {
        System.out.println("Into the writer!!");
        return new ItemWriter<Students>() {
            @Override
            public void write(List<? extends Students> list) throws Exception {
                System.out.printf("Received a list of size %s", list.size());
                list.forEach(System.out::println);
            }
        }; 
    }


//My ChunkBased Step
 @Bean
    public Step readFromExcelChunkStep() {
        return this.stepBuilderFactory.get("readFromExcelChunkStep")
                .<Students, Students>chunk(5)
                .reader(xlsItemReader())
                .writer(xlsItemWriter()).build();
    }

//MY JOB WHICH WOULD READ FROM THE EXCEL FILE

@Bean
    public Job readFromExcelJob(){
        System.out.println("starting job");
        return this.jobBuilderFactory
                .get("readFromExcelJob")
                .start(readFromExcelChunkStep()).build();
    }


}
 public static void main(String[] args) {
        SpringApplication.run(JobConfig.class, args);
    }

My Students Class

import lombok.Getter;
import lombok.RequiredArgsConstructor;
import lombok.Setter;
import lombok.ToString;

@Getter
@Setter
@ToString
@RequiredArgsConstructor
public class Students {

    private String Matno;
    private String College;
    private String Dept;
    private String Program;
    private String Level;
    private String fullname;
    private String Email;
    private String RegStatus;
    private String Printdate;
    private String Hall;
    private String HallClearance;
    private String Sn;

}

When I run the application, I get the following output: But notice as it goes into the xlsItemWriter, it doesnt execute the return function

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v2.7.1)

2022-07-08 14:16:50.632  INFO 34196 --- [           main] c.d.spring_batch.SpringBatchApplication  : Starting SpringBatchApplication using Java 11.0.15 on ISW2-220303-429 with PID 34196 (C:\Users\a.b\Documents\GitHub\spring_batch\target\classes started by a.b in C:\Users\a.b\Documents\GitHub\spring_batch)
2022-07-08 14:16:50.639  INFO 34196 --- [           main] c.d.spring_batch.SpringBatchApplication  : No active profile set, falling back to 1 default profile: "default"
2022-07-08 14:16:51.640  INFO 34196 --- [           main] .s.d.r.c.RepositoryConfigurationDelegate : Bootstrapping Spring Data JDBC repositories in DEFAULT mode.
2022-07-08 14:16:51.680  INFO 34196 --- [           main] .s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 26 ms. Found 0 JDBC repository interfaces.
2022-07-08 14:16:52.860  INFO 34196 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Starting...
2022-07-08 14:16:53.448  INFO 34196 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Start completed.
starting job
XLS READER!!!
Into the writer!!
2022-07-08 14:16:53.698  INFO 34196 --- [           main] o.s.b.c.r.s.JobRepositoryFactoryBean     : No database type set, using meta data indicating: SQLSERVER
2022-07-08 14:16:53.871  INFO 34196 --- [           main] o.s.b.c.l.support.SimpleJobLauncher      : No TaskExecutor has been set, defaulting to synchronous executor.
2022-07-08 14:16:54.026  WARN 34196 --- [           main] o.s.data.convert.CustomConversions       : Registering converter from class microsoft.sql.DateTimeOffset to class java.time.OffsetDateTime as reading converter although it doesn't convert from a store-supported type; You might want to check your annotation setup at the converter implementation
2022-07-08 14:16:54.212  INFO 34196 --- [           main] c.d.spring_batch.SpringBatchApplication  : Started SpringBatchApplication in 4.478 seconds (JVM running for 6.961)
2022-07-08 14:16:54.234  INFO 34196 --- [ionShutdownHook] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Shutdown initiated...
2022-07-08 14:16:54.272  INFO 34196 --- [ionShutdownHook] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Shutdown completed.

Process finished with exit code 0

Answer 1

Oh, your project didn't just got run... You can add code in your main method for below

public static void main(String[] args) {
        ApplicationContext applicationContext = SpringApplication.run(SpringBatchApplication.class, args);
        runJob(applicationContext);
    }
    private static void runJob(ApplicationContext applicationContext) {
        String jobName = "readFromExcelJob";
        JobLauncher jobLauncher = applicationContext.getBean(JobLauncher.class);
        JobParameters jobParameters = new JobParametersBuilder().addDate("test", new Date()).toJobParameters();

        ExitStatus exitCode = null;
        try {
            JobExecution run = jobLauncher.run(applicationContext.getBean(jobName, Job.class), jobParameters);
            exitCode = run.getExitStatus();
        } catch (JobExecutionAlreadyRunningException | JobRestartException
                | JobInstanceAlreadyCompleteException | JobParametersInvalidException e) {
            log.error("Job {} failed:\n{}", jobName, e);
        }
        log.info("Job {} run end, exitCode: {}", jobName, exitCode);
        System.exit(1);
    }

Answer 2

So, I realised my job wasn't actually getting run because of a property I added in my application.properties file.

I had spring.batch.job.enabled = false.

I think I saw it in an article I was reading.

Anyways, I went ahead and commented it as follows

# spring.batch.job.enabled=false

You can use the following property to specify what jobs should be executed when the application runs

spring.batch.job.names= readFromExcelJob

The job then runs! But it only runs one instance of the job with no parameters.

2022-07-11 09:26:00.920  INFO 18016 --- [main] o.s.b.c.l.support.SimpleJobLauncher : Job: [SimpleJob: [name=readFromExcelJob]] launched with the following parameters: [{}]

This means that if the job Exit Status is marked COMPLETED, you cannot re run that job unless you drop the tables provided by the job repository (not recommended)

You can manually implement a job launcher and provide parameters which would create new job Instances as well as new job Executions

To create a job launcher as well as its parameters, you can try this

    @Bean
    public void runJob() {
        JobParameters jobParameters = new JobParametersBuilder()
                .addLong("startHere: ", System.currentTimeMillis()).toJobParameters();
        try {
            jobLauncher.run(readFromExcelJob(), jobParameters); // I specified my Job to be Executed here
        } catch (JobExecutionAlreadyRunningException | JobRestartException | JobInstanceAlreadyCompleteException | JobParametersInvalidException e) {
            e.printStackTrace();
        }
    }