Spring Batch RabbitMQ issue - spring

Question

I am looking to integrate the Spring Batch with RabbitMQ. I've developed code like below but no data is passing over the channel. What's wrong in the code ?
CustomerMessageChannel.java
public interface CustomerMessageChannel {
#Output("customerMessageChannel")
MessageChannel customerMessageChannel();
}
Customer.java
#AllArgsConstructor
#NoArgsConstructor
#Builder
#Data
#JsonIgnoreProperties(ignoreUnknown = true)
public class Customer implements Serializable {
private static final long serialVersionUID = 1L;
private Long id;
private String firstName;
private String lastName;
private String birthdate;
}
CustomerFieldSetMapper.java
public class CustomerFieldSetMapper implements FieldSetMapper<Customer> {
#Override
public Customer mapFieldSet(FieldSet fieldSet) throws BindException {
return Customer.builder()
.id(fieldSet.readLong("id"))
.firstName(fieldSet.readRawString("firstName"))
.lastName(fieldSet.readRawString("lastName"))
.birthdate(fieldSet.readRawString("birthdate"))
.build();
}
}
JobConfig.java
#Configuration
public class JobConfig {
#Autowired
private StepBuilderFactory stepBuilderFactory;
#Autowired
private JobBuilderFactory jobBuilderFactory;
#Autowired
private AmqpTemplate amqpTemplate;
#Bean
public FlatFileItemReader<Customer> customerItemReader() {
FlatFileItemReader<Customer> reader = new FlatFileItemReader<>();
reader.setLinesToSkip(1);
reader.setResource(new ClassPathResource("/data/customer.csv"));
DelimitedLineTokenizer tokenizer = new DelimitedLineTokenizer();
tokenizer.setNames(new String[] { "id", "firstName", "lastName", "birthdate" });
DefaultLineMapper<Customer> customerLineMapper = new DefaultLineMapper<>();
customerLineMapper.setLineTokenizer(tokenizer);
customerLineMapper.setFieldSetMapper(new CustomerFieldSetMapper());
customerLineMapper.afterPropertiesSet();
reader.setLineMapper(customerLineMapper);
return reader;
}
#Bean
public AmqpItemWriter<Customer> amqpItemWriter() throws Exception{
return new AmqpItemWriter<>(amqpTemplate);
}
#Bean
public Step step1() throws Exception {
return stepBuilderFactory.get("step1")
.<Customer, Customer>chunk(10)
.reader(customerItemReader())
.writer(amqpItemWriter())
.build();
}
#Bean
public Job job() throws Exception {
return jobBuilderFactory.get("job")
.incrementer(new RunIdIncrementer())
.start(step1())
.build();
}
}
application.properties
spring.rabbitmq.host=localhost
spring.rabbitmq.port=5672
spring.rabbitmq.username=guest
spring.rabbitmq.password=guest
spring.cloud.stream.bindings.customerMessageChannel.destination=customerMessageChannel
spring.cloud.stream.default.contentType=application/json
customer.csv
id,firstName,lastName,
1, John, Doe,10-10-1952 10:10:10
2, Amy, Eugene,05-07-1985 17:10:00
3, Laverne, Mann,11-12-1988 10:10:10
4, Janice, Preston,19-02-1960 10:10:10
5, Pauline, Rios,29-08-1977 10:10:10
6, Perry, Burnside,10-03-1981 10:10:10
7, Todd, Kinsey,14-12-1998 10:10:10
8, Jacqueline, Hyde,20-03-1983 10:10:10
9, Rico, Hale,10-10-2000 10:10:10
10, Samuel, Lamm,11-11-1999 10:10:10
11, Robert, Coster,10-10-1972 10:10:10
12, Tamara, Soler,02-01-1978 10:10:10
13, Justin, Kramer,19-11-1951 10:10:10
14, Andrea, Law,14-10-1959 10:10:10
15, Laura, Porter,12-12-2010 10:10:10
16, Michael, Cantu,11-04-1999 10:10:10
17, Andrew, Thomas,04-05-1967 10:10:10
18, Jose, Hannah,16-09-1950 10:10:10
19, Valerie, Hilbert,13-06-1966 10:10:10
20, Patrick, Durham,12-10-1978 10:10:10
SpringBatchAmqpApplication.java
#EnableBatchProcessing
#SpringBootApplication
public class SpringBatchAmqpApplication {
public static void main(String[] args) {
SpringApplication.run(SpringBatchAmqpApplication.class, args);
}
}

Answer 1

You need to configure an exchange and routing key for the template - by default, RabbitMQ will discard unroutable messages.
https://docs.spring.io/spring-boot/docs/current/reference/html/appendix-application-properties.html#spring.rabbitmq.template.exchange
https://docs.spring.io/spring-boot/docs/current/reference/html/appendix-application-properties.html#spring.rabbitmq.template.routing-key
You also don't seem to be referencing customerMessageChannel any place so it's not clear what you are expecting.
To consume from the spring-cloud-stream destination, you need #EnableBinding(CustomerMessageChannel.class) and a #StreamListener method. However, that annotation model is now deprecated in favor of the functional programming model.
https://docs.spring.io/spring-cloud-stream/docs/3.1.0/reference/html/spring-cloud-stream.html#spring-cloud-stream-overview-producing-consuming-messages