How do I set JobParameters in spring batch with spring-boot

Question

I followed the guide at http://spring.io/guides/gs/batch-processing/ but it describes a job with no configurable parameters. I'm using Maven to build my project.

I'm porting an existing job that I have defined in XML and would like to pass-in the jobParameters through the command.

I tried the following :

@Configuration
@EnableBatchProcessing
public class MyBatchConfiguration {

    // other beans ommited

    @Bean 
    public Resource destFile(@Value("#{jobParameters[dest]}") String dest) {
        return new FileSystemResource(dest);
    }

}

Then I compile my project using :

mvn clean package

Then I try to launch the program like this :

java my-jarfile.jar dest=/tmp/foo

And I get an exception saying :

[...]
Caused by: org.springframework.expression.spel.SpelEvaluationException: 
EL1008E:(pos 0): Field or property 'jobParameters' cannot be found on object of 
type 'org.springframework.beans.factory.config.BeanExpressionContext'

Thanks !

Answer 1

I managed to get this working by simply annotating my bean as follows :

@Bean 
@StepScope
public Resource destFile(@Value("#{jobParameters[dest]}") String dest) {
    return new FileSystemResource(dest);
}

Answer 2

Parse in job parameters from the command line and then create and populate JobParameters.

public JobParameters getJobParameters() {
    JobParametersBuilder jobParametersBuilder = new JobParametersBuilder();
    jobParametersBuilder.addString("dest", <dest_from_cmd_line);
    jobParametersBuilder.addDate("date", <date_from_cmd_line>);
    return jobParametersBuilder.toJobParameters();
}

Pass them to your job via JobLauncher -

JobLauncher jobLauncher = context.getBean(JobLauncher.class);
JobExecution jobExecution = jobLauncher.run(job, jobParameters);

Now you can access them using code like -

@Bean 
@StepScope
public Resource destFile(@Value("#{jobParameters[dest]}") String dest) {
    return new FileSystemResource(dest);
}

Or in a @Configuration class that is configuring Spring Batch Job artifacts like - ItemReader, ItemWriter, etc...

@Bean
@StepScope
public JdbcCursorItemReader<MyPojo> reader(@Value("#{jobParameters}") Map jobParameters) {
    return new MyReaderHelper.getReader(jobParameters);
}