Axon 框架：聚合 Autowired Bean 在测试中抛出 NullPointerException

Question

Springboot 和 Axon：基本上，我正在对使用三个不同 ObjectMapper 实例的聚合进行单元测试，每个实例具有不同的配置。这些是在配置类中定义的：

    @Configuration
    public class JacksonConfiguration {

    @Bean(name="flatMapper")
    @Primary
    public ObjectMapper flatMapper(){
        return new ObjectMapper();
    }

    @Bean(name="unknownPropertiesMapper")
    public ObjectMapper unknownPropertiesMapper(){
        ObjectMapper mapper = new ObjectMapper();
        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        return mapper;
    }

    @Bean(name="nullPropertiesMapper")
    public ObjectMapper nullPropertiesMapper(){
        ObjectMapper mapper = new ObjectMapper();
        mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
        return mapper;
    }

}

它们被注入并在我的聚合中使用，如下所示：

@Aggregate
@Data
@Component
public class MyAggregate {

    @Autowired
    @Qualifier("flatMapper")
    private ObjectMapper flatMapper;

    @Autowired
    @Qualifier("unknownPropertiesMapper")
    private ObjectMapper unknownPropertiesMapper;

    @Autowired
    @Qualifier("nullPropertiesMapper")
    private ObjectMapper nullPropertiesMapper;


    @AggregateIdentifier
    private String id;

  //Methods and Handlers: a method is using "unknownPropertiesMapper" is "changedKeySet" 

当我运行 SpringBootApplication 时，一切都正确实例化并按预期工作，但是在测试时我在它们的实例上得到 NullPointerException：

@ContextConfiguration(classes = JacksonConfiguration.class)
@SpringBootTest(classes = OccurrenceAggregate.class)
@ComponentScan(basePackageClasses = MyAggregate.class)
public class AggregateTest {
    
    private FixtureConfiguration<MyAggregate> fixture;

    @BeforeEach
    public void setUp() {
        fixture = new AggregateTestFixture<>(MyAggregate.class);
    }

    @Test
    public void myTest() {

       fixture.givenNoPriorActivity().... 

    }

测试控制台：

org.axonframework.test.AxonAssertionError: The command handler threw an unexpected exception

Expected <ANYTHING> but got <exception of type [NullPointerException]>. Stack trace follows:
java.lang.NullPointerException
    at com.example.business.aggregates.MyAggregate.changedKeySet(MyAggregate.java:185)

changedKeySet() 抛出 NPE，因为它使用 unknownPropertiesMapper 并且它的值为 null。 正如我所提到的，当我运行 Main 类但在测试中（Junit5）时它工作得很好。

Answer 1

聚合设置不正确。将 Spring Bean 注入聚合的正确方法是将其添加到 CommandHandler 方法中。

@CommandHandler
    public void handle(ACommand cmd, ObjectMapper flatMapper) {

在测试装置中，您可以这样注入：

fixture.registerInjectableResource(flatMapper);