#SpringBatch MultiResourcePartitioner job sample

MultiResourcePartitionerSample.java

package org.springframework.batch.sample;

import org.springframework.batch.core.Job;
import org.springframework.batch.core.JobParameters;
import org.springframework.batch.core.JobParametersBuilder;
import org.springframework.batch.core.Step;
import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepScope;
import org.springframework.batch.core.launch.JobLauncher;
import org.springframework.batch.core.partition.support.MultiResourcePartitioner;
import org.springframework.batch.item.file.FlatFileItemReader;
import org.springframework.batch.item.file.builder.FlatFileItemReaderBuilder;
import org.springframework.batch.item.file.mapping.PassThroughLineMapper;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.Resource;
import org.springframework.core.task.SimpleAsyncTaskExecutor;

@Configuration
@EnableBatchProcessing
public class MultiResourcePartitionerSample {

	private final JobBuilderFactory jobs;
	private final StepBuilderFactory steps;

	public MultiResourcePartitionerSample(JobBuilderFactory jobs, StepBuilderFactory steps) {
		this.jobs = jobs;
		this.steps = steps;
	}

	@Bean
	public Step managerStep() {
		return steps.get("managerStep")
				.partitioner(workerStep().getName(), partitioner(null))
				.step(workerStep())
				.taskExecutor(new SimpleAsyncTaskExecutor())
				.build();
	}

	@StepScope
	@Bean
	public MultiResourcePartitioner partitioner(@Value("#{jobParameters['inputFiles']}") Resource[] resources) {
		MultiResourcePartitioner partitioner = new MultiResourcePartitioner();
		partitioner.setResources(resources);
		return partitioner;
	}

	@StepScope
	@Bean
	public FlatFileItemReader<String> personFileReader(@Value("#{stepExecutionContext['fileName']}") Resource resource) {
		return new FlatFileItemReaderBuilder<String>()
				.name("itemReader")
				.resource(resource)
				.lineMapper(new PassThroughLineMapper())
				.build();
	}
	@Bean
	public Step workerStep() {
		return steps.get("workerStep")
				.<String, String>chunk(5)
				.reader(personFileReader(null))
				.writer(items -> items.forEach(System.out::println))
				.build();
	}

	@Bean
	public Job job() {
		return jobs.get("job")
				.start(managerStep())
				.build();
	}

	public static void main(String[] args) throws Exception {
		ApplicationContext context = new AnnotationConfigApplicationContext(MultiResourcePartitionerSample.class);
		JobLauncher jobLauncher = context.getBean(JobLauncher.class);
		Job job = context.getBean(Job.class);
		JobParameters jobParameters = new JobParametersBuilder()
				.addString("inputFiles", "file:///tmp/data/*.csv")
				.toJobParameters();
		jobLauncher.run(job, jobParameters);
	}

}