SpringBoot 2 无法绑定 ConfigurationProperties

Posted 2023-02-26

【中文标题】SpringBoot 2 无法绑定 ConfigurationProperties

【英文标题】：SpringBoot 2 fails to bing ConfigurationProperties

【发布时间】：2020-05-21 16:20:38

【问题描述】：

我的属性如下：

@Component
@Validated
@ConfigurationProperties("kafka")
public class KafkaProperties 

    @NotEmpty
    String broker;

    @NotEmpty
    String groupId;

    @NotEmpty
    String resetOffset = "latest";

    @NotEmpty
    String topic;

我的 application.properties 像：

kafka.broker=localhost:9092
kafka.groupid=pdp-group
kafka.offset-reset=latest
kafka.topic=pdp-product-fragment

测试是：

@ExtendWith(SpringExtension.class)
@Import(ReactiveKafkaConsumerTest.TestConfig.class)
@PropertySource("classpath:application.properties")
class ReactiveKafkaConsumerTest 

    @RegisterExtension
    static final SharedKafkaTestResource sharedKafkaTestResource = new SharedKafkaTestResource();

    static class TestConfig extends KafkaConfig 

        Consumer<ReceiverRecord<String, String>> mockConsumer = mock(Consumer.class);

        @Override
        List<String> topics() 
            String topicName = Integer.toHexString(Math.abs(new Random().nextInt()));
            var kafkaTestUtils = sharedKafkaTestResource.getKafkaTestUtils();
            kafkaTestUtils.createTopic(topicName, 4, (short) 1);
            return asList(topicName);
        

        @Override
        public Map<String, Object> consumerProps() 
            Map<String, Object> props = super.consumerProps();
            props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, sharedKafkaTestResource.getKafkaConnectString());
            props.put(ConsumerConfig.GROUP_ID_CONFIG, "group");
            props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
            return props;
        

        @Override
        public Supplier<Consumer<ReceiverRecord<String, String>>> consumerSupplier() 
            return () -> mockConsumer;
        


    

    @Autowired
    List<String> topics;

    @Autowired
    TestConfig testConfig;

    @Test
    @DirtiesContext
    public void testReceiveMessages() 
        var kafkaTestUtils = sharedKafkaTestResource.getKafkaTestUtils();

        IntStream.range(0, 4)
                .forEach(i -> kafkaTestUtils.produceRecords(4, topics.get(0), i));


        ArgumentCaptor<ReceiverRecord<String, String>> captor = ArgumentCaptor.forClass(ReceiverRecord.class);
        verify(testConfig.mockConsumer, timeout(10000).times(16))
                .accept(captor.capture());

        var recordsPerPartition = captor.getAllValues().stream()
                .collect(Collectors.groupingBy(r -> r.partition()));

        assertThat(recordsPerPartition.keySet(), containsInAnyOrder(0, 1, 2, 3));
        assertEquals(16, recordsPerPartition.values().stream().mapToInt(l -> l.size()).sum());
    

它失败了：

Caused by: org.springframework.boot.context.properties.bind.validation.BindValidationException: Binding validation errors on kafka
   - Field error in object 'kafka' on field 'broker': rejected value [null]; codes [NotEmpty.kafka.broker,NotEmpty.broker,NotEmpty]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [kafka.broker,broker]; arguments []; default message [broker]]; default message [must not be empty]
   - Field error in object 'kafka' on field 'topic': rejected value [null]; codes [NotEmpty.kafka.topic,NotEmpty.topic,NotEmpty]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [kafka.topic,topic]; arguments []; default message [topic]]; default message [must not be empty]
   - Field error in object 'kafka' on field 'groupId': rejected value [null]; codes [NotEmpty.kafka.groupId,NotEmpty.groupId,NotEmpty]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [kafka.groupId,groupId]; arguments []; default message [groupId]]; default message [must not be empty]

我尝试了很多方法，例如：

添加 SpringBootTest 替换 PropertySource 为 TestPropertySource

Spring boot 版本为：2.2.2.RELEASE

有人有想法吗？

【参考方案1】：

将属性或 yaml 文件绑定到 POJO 是 Spring Boot 功能 Loading YAML，因此如果您想在测试期间使用它，您需要使用 @SpringBootTest 加载测试应用程序上下文。我也建议使用 @Configuration 与 @Configurationproperties。请参阅here 了解更多信息

注意：如果我们不在POJO中使用@Configuration，那么我们需要在主Spring应用类中添加@EnableConfigurationProperties(ConfigProperties.class)来将属性绑定到POJO中：