确保检查您的项目结构。属性文件应该在类路径上，以便Spring Boot可以找到并使用它。 例如，Maven在此处定义的项目结构：https://maven.apache.org/guides/introduction/introduction-to-the-standard-directory-layout.html

对于Maven，您的配置文件应放在以下目录中：

src/main/resources/application.yml
src/test/resources/application.yml

似乎未创建bean（因此出现null错误）。

尝试之一：

• 在您的SnmpProperties配置类的顶部添加@Configuration
• 在测试类的顶部添加@EnableConfigurationProperties(SnmpProperties.class)

来源：https://www.baeldung.com/configuration-properties-in-spring-boot

@CamelSpringBootTest
@SpringBootTest(classes = [SnmpTrapReceiverCamelApplication::class])
@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
@DisableJmx(false)
@ExtendWith(MockitoExtension::class)
@EnableAutoConfiguration
class SnmpTrapRouteTest {

    object TestSnmpConstants {
        const val SNMP_REAL_ENDPOINT_ID = "snmp-trap-route"
        const val SNMP_DIRECT_REPLACEMENT_ENDPOINT = "direct:snmp-from"
        const val TRAP_REQUEST_ID = 123456789
        const val TRAP_OID = "1.2.3.4.5"
        const val TRAP_PAYLOAD = "snmp-trap-payload"
    }

    @MockBean
    lateinit var repository: IPduEventRepository

    @Produce
    lateinit var producerTemplate: ProducerTemplate

    @Autowired
    lateinit var camelContext: CamelContext

    @Test
    @Throws(Exception::class)
    fun `Should call save method on the repository when PDU TRAP event supplied`() {

        // Replace our SNMP consumer route with a dummy route than can be called from a producer internally.
        // Since our snmp endpoint is an asynchronous consumer (meaning it only receives data from external events)
        // we need to use the "direct:" component to allow a producer to internally call what is ordinarily an external
        // event-driven endpoint.  Otherwise we will get a Connection Refused error,as we cannot access the external
        // system/socket.
        AdviceWithRouteBuilder.adviceWith(camelContext,TestSnmpConstants.SNMP_REAL_ENDPOINT_ID) { routeBuilder ->
            routeBuilder.replaceFromWith(TestSnmpConstants.SNMP_DIRECT_REPLACEMENT_ENDPOINT)
        }

        // Create the PDU object to send to the SNMP endpoint
        val trap = PDU()
        trap.type = PDU.TRAP
        trap.requestID = Integer32(TestSnmpConstants.TRAP_REQUEST_ID)
        trap.add(VariableBinding(OID(TestSnmpConstants.TRAP_OID),OctetString(TestSnmpConstants.TRAP_PAYLOAD)))

        // "direct:" endpoints only send DefaultMessage objects.  These are not castable to SnmpMessage objects,// so need to overwrite the exchange IN message to be an SnmpMessage object
        val exchange = DefaultExchange(camelContext)
        exchange.setIn(SnmpMessage(camelContext,trap))

        // ProducerTemplates need a default endpoint specified.
        // The ProducerTemplate provides us with a producer that can directly deliver messages to consumers defined
        // in the camelContext,using the "direct:" component (see above)
        producerTemplate.setDefaultEndpointUri(TestSnmpConstants.SNMP_DIRECT_REPLACEMENT_ENDPOINT)
        producerTemplate.send(exchange)

        // Verify that the repository.save() was invoked
        verify(repository,atLeast(1)).save(any())
    }
}