Example of how to use a custom JobParametersConverter with Spring Batch #SpringBatch

HelloWorldJobApplication.java

package com.example.helloworldjob;

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.converter.JobParametersConverter;
import org.springframework.batch.core.step.tasklet.Tasklet;
import org.springframework.batch.repeat.RepeatStatus;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.Properties;

@SpringBootApplication
@EnableBatchProcessing
@Configuration
public class HelloWorldJobApplication {
	
	@Value("${prefix}")
	private String prefix;
	
	@Autowired
	private JobBuilderFactory jobBuilderFactory;
	
	@Autowired
	private StepBuilderFactory stepBuilderFactory;
	
	@Bean
	public JobParametersConverter jobParametersConverter() {
		return new JobParametersConverter() {
			@Override
			public JobParameters getJobParameters(Properties properties) {
				JobParametersBuilder jobParametersBuilder = new JobParametersBuilder();
				String property = properties.getProperty("--name");
				jobParametersBuilder.addString("name", property, true);
				return jobParametersBuilder.toJobParameters();
			}

			@Override
			public Properties getProperties(JobParameters jobParameters) {
				Properties properties = new Properties();
				String name = jobParameters.getString("name");
				properties.setProperty("name", name);
				return properties;
			}
		};
	}
	
	@Bean
	public Step step1() {
		return stepBuilderFactory.get("step1")
				.tasklet(tasklet())
				.build();
	}
	
	@Bean
	public Tasklet tasklet() {
		return (contribution, chunkContext) -> {
			String name = (String) chunkContext.getStepContext().getJobParameters().get("name");
			System.out.println(prefix + name);
			return RepeatStatus.FINISHED;
		};
	}
	
	@Bean
	public Job job() {
		return jobBuilderFactory.get("hello-world-job")
				.start(step1())
				.build();
	}
	
	// run with --prefix="hello " --name=world => prints "hello world"
	// comment the jobParametersConverter bean and run again => prints "hello null"
	public static void main(String[] args) {
		SpringApplication.run(HelloWorldJobApplication.class, args);
	}
}