Spring Batch: chunk over enum and pass it to the reader

Question

In our domain, we have list of cities which our service is active there. Using Spring batch I would like to call a REST web-service with parameter of city names.

Maybe I'm wring in the usage of library, but I mean some thing like this:

@Bean
public Step step1(ItemWriter writer) {
    return stepBuilderFactory.get("step1")
            .chunk(InstalledCities.values())
            .reader(reader())
            .processor(processor())
            .writer(writer)
            .build();
@Bean
public ItemReader<BikerCashOutDto> reader(InstalledCities city) {
    theSrevice.call(city);
}

Answer 1

If I understand correctly, you need to iterate over a list of cities and for each city, call a rest service. If this is correct, here is how you can proceed:

• Create an item reader that return cities one by one
• Create an item processor that calls the rest endpoint for each city

For example:

@Bean
public ItemReader<City> reader(List<City> cities) {
    return new ListItemReader<>(cities); // or get cities from InstalledCities
}

@Bean
public ItemProcessor<City, City> itemProcessor(TheSrevice theSrevice) {
    return new ItemProcessor<City, City>() {
        @Override
        public City process(City city) throws Exception {
            Result result = theSrevice.call(city);
            // use service result if any or enrich city item
            return city;
        }
    };
}

Hope this helps.