Nsryjdtyk

I would like to define an
<int-jdbc:outbound-gateway/> with query and without update to retrieve data from database. Then I would like to use the int-jdbc:outbound-gateway as an implementation of Service.findSomeData() interface method. The data retrieved from interface implementation is used in my custom transformer's CheckService class. See the configuration below:

<int:service-activator method=“performCheck”>

       <bean class=“com.example.service.CheckService”

             c:service-ref=“service”

 </int:service-activator>



<int:gateway id=“service” service-interface=“com.example.service.Service”>

   <int:method name=“findSomeData” request-channel=“jdbcChan” reply-channel=“jdbcChanReply”/>

</int:gateway>



<int-jdbc:outbound-gateway request-channel=“jdbcChan”

                          data-source=“pooledDs” row-mapper=“dataRowMapper” reply-channel=“jdbcChanReply”>

   <int-jdbc:query>

       select some, data from some_table

   </int-jdbc:query>

The problem is that I get ReplyRequiredException exception when I move my payload to jdbcChan:

org.springframework.integration.handler.ReplyRequiredException: No reply produced by handler 'org.springframework.integration.jdbc.JdbcOutboundGateway#0', and its 'requiresReply' property is set to true.

I decided to pay more attention on example located in spring in spring-integration-samples repository on GitHub, but looks like it also does not work as expected. I get exactly the same exception in example project trying to find User by name foo. You can easily reproduce the exception with basic jdbc example located on GitHub and the following test method:

@Test

public void findPerson() {

    ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(

            "/META-INF/spring/integration/spring-integration-context.xml");

    PersonService service = context.getBean(PersonService.class);

    final List<Person> foo = service.findPersonByName("foo");

    assertThat(foo, is(not(empty())));

}

Am I doing it wrong or there is a bug in latest Spring Integration JDBC? (for me looks like even example is broken)

I fixed the sample.

We changed the default for requires-reply to true a long time ago but the sample was never updated.

assertThat(foo, is(not(empty())));

However, the List<Person> is null when no results are received.

EDIT

But I would expect empty list instead of a null if ResultSet was empty.

That's not how it works.

If the resultSet is empty, null is returned (hence the original error you were seeing).

If the resultSet has 1 entry, just that entry is returned.

Otherwise a list of entities is returned.

Object payload = list;

if (list.isEmpty()) {

    return null;

}

if (list.size() == 1) {

    payload = list.get(0);

}

return payload;

It's been like that forever but I believe the single Object Vs. List is wrong (if maxRows > 1).

maxRows is 1 by default so it made sense then; however, if maxRows is > 1 and only 1 row is returned I think it should still be a list of 1. The application shouldn't have to check the type of the result. It either expects a list or a single object (or null). INT-4559.