Como usar ClassifierCompositeItemProcessor no Spring Batch e gravar dados na mesma tabela para Insert e Upsert?

Question

Passei pelo link - https://github.com/spring-projects/spring-batch/blob/master/spring-batch-infrastructure/src/test/java/org/springframework/batch/item/support/ClassifierCompositeItemProcessorTests.java, mas não tirou muito proveito disso.

Estou tentando substituir a lógica de mapeamento ETL Informatica no lote. Eu estou olhando para separar Status=Ie Status=Upara (Individual) processador separado e posteriormente executar a pesquisa e massagear os dados e, em seguida, escrever os registros diretamente para a mesa para Status = I e de status = U, executar outra lógica complexa (como pesquisas, massagem e combinar e mesclar lógica) e, em seguida, fazer o upsert desses registros novamente na mesma tabela.

Eu tentei fazer POC, onde procuro segregar os registros no processador

CustomerClassifier.java

public class CustomerClassifier implements Classifier<Customer, ItemProcessor<Customer, Customer>> {

    private ItemProcessor<Customer, Customer> insertCustomerProcessor;
    private ItemProcessor<Customer, Customer> updateCustomerProcessor;
    
    public CustomerClassifier(ItemProcessor<Customer, Customer> evenCustomerProcessor, ItemProcessor<Customer, Customer> oddCustomerProcessor) {
        this.insertCustomerProcessor= insertCustomerProcessor;
        this.updateCustomerProcessor= updateCustomerProcessor;
    }
    
    @Override
    public ItemProcessor<Customer, Customer> classify(Customer customer) {
        return customer.getStatus().equals("I") ? insertCustomerProcessor : updateCustomerProcessor;
    }
}

OddCustomerProcessor.java

public class OddCustomerProcessor implements ItemProcessor<Customer, Customer> {

    @Override
    public Customer process(Customer item) throws Exception {
        Customer customer = new Customer();
        // Perform some msaaging and lookups here
        customer.setId(item.getId());
        customer.setFirstName(item.getFirstName());
        customer.setLastName(item.getLastName());
        customer.setBirthdate(item.getBirthdate());
        customer.setStatus(item.getStatus());
        return customer;
    }
}

EvenCustomerProcessor.java

public class EvenCustomerProcessor implements ItemProcessor<Customer, Customer> {

    @Override
    public Customer process(Customer item) throws Exception {
        Customer customer = new Customer();
        // Perform some msaaging and lookups here
        customer.setId(item.getId());
        customer.setFirstName(item.getFirstName());
        customer.setLastName(item.getLastName());
        customer.setBirthdate(item.getBirthdate());
        customer.setStatus(item.getStatus());
        return customer;
    }
}

CustomLineAggregator.java

public class CustomLineAggregator implements LineAggregator<Customer> {
    private ObjectMapper objectMapper = new ObjectMapper();

    @Override
    public String aggregate(Customer item) {
        try {
            return objectMapper.writeValueAsString(item);
        } catch (Exception e) {
            throw new RuntimeException("Unable to serialize Customer", e);
        }
    }
}

Customer.java

@Data
@AllArgsConstructor
@Builder
@NoArgsConstructor
public class Customer {
    private Long id;
    private String firstName;
    private String lastName;
    private String birthdate;
    private String status;
}

Erro-

O método setClassifier (Classifier <? Super Customer, ItemProcessor <?,? Extends Customer >>) no tipo ClassifierCompositeItemProcessor <Customer, Customer> não é aplicável para os argumentos (CustomerClassifier)

Configuração

@Configuration
public class JobConfiguration {
    @Autowired
    private JobBuilderFactory jobBuilderFactory;
    
    @Autowired
    private StepBuilderFactory stepBuilderFactory;
    
    @Autowired
    private DataSource dataSource;
    
    @Bean
    public JdbcPagingItemReader<Customer> customerPagingItemReader(){
        // reading database records using JDBC in a paging fashion
        JdbcPagingItemReader<Customer> reader = new JdbcPagingItemReader<>();
        reader.setDataSource(this.dataSource);
        reader.setFetchSize(1000);
        reader.setRowMapper(new CustomerRowMapper());
        
        // Sort Keys
        Map<String, Order> sortKeys = new HashMap<>();
        sortKeys.put("id", Order.ASCENDING);
        
        // MySQL implementation of a PagingQueryProvider using database specific features.
        MySqlPagingQueryProvider queryProvider = new MySqlPagingQueryProvider();
        queryProvider.setSelectClause("id, firstName, lastName, birthdate");
        queryProvider.setFromClause("from customer");
        queryProvider.setSortKeys(sortKeys);
        
        reader.setQueryProvider(queryProvider);
        
        return reader;
    }
    
    @Bean
    public EvenCustomerProcessor evenCustomerProcessor() {
        return new EvenCustomerProcessor();
    }
    
    @Bean
    public OddCustomerProcessor oddCustomerProcessor() {
        return new OddCustomerProcessor();
    }
    
    @Bean 
    public JdbcBatchItemWriter<Customer> customerItemWriter(){
    JdbcBatchItemWriter<Customer> batchItemWriter = new JdbcBatchItemWriter<>();
    batchItemWriter.setDataSource(dataSource);
    batchItemWriter.setSql(""); // Query Goes here
    return batchItemWriter;
}
    
    @Bean
    public ClassifierCompositeItemProcessor<Customer, Customer> classifierCustomerCompositeItemProcessor() throws Exception{
        ClassifierCompositeItemProcessor<Customer, Customer> itemProcessor = new ClassifierCompositeItemProcessor<>();
        itemProcessor.setClassifier(new CustomerClassifier(evenCustomerProcessor(), oddCustomerProcessor()));
    }
    
    @Bean
    public Step step1() throws Exception {
        return stepBuilderFactory.get("step1")
                .<Customer, Customer> chunk(10)
                .reader(customerPagingItemReader())
                .processor(classifierCustomerCompositeItemProcessor())
                .writer(customerItemWriter())
                .build();
    }
    
    @Bean
    public Job job() throws Exception {
        return jobBuilderFactory.get("job")
                .start(step1())
                .build();
    }
}

Answer 1

Você pode remover CustomerClassifiere definir o processador de item composto da seguinte maneira:

@Bean
public ClassifierCompositeItemProcessor<Customer, Customer> classifierCustomerCompositeItemProcessor(
        EvenCustomerProcessor evenCustomerProcessor,
        OddCustomerProcessor oddCustomerProcessor
) {
    ClassifierCompositeItemProcessor<Customer, Customer> itemProcessor = new ClassifierCompositeItemProcessor<>();
    itemProcessor.setClassifier(new Classifier<Customer, ItemProcessor<?, ? extends Customer>>() {
        @Override
        public ItemProcessor<?, ? extends Customer> classify(Customer customer) {
            return customer.getStatus().equals("I") ? evenCustomerProcessor : oddCustomerProcessor;
        }
    });
    return itemProcessor;
}

Em seguida, atualize sua definição de etapa da seguinte maneira:

@Bean
public Step step1() throws Exception {
    return stepBuilderFactory.get("step1")
            .<Customer, Customer> chunk(10)
            .reader(customerPagingItemReader())
            .processor(classifierCustomerCompositeItemProcessor(evenCustomerProcessor(), oddCustomerProcessor()))
            .writer(customerItemWriter())
            .build();
}