Spring Cloud GCP PubSub版本迁移报错：DefaultSubscriberFactory构造参数不匹配

Spring Cloud GCP 5.x版本对DefaultSubscriberFactory的构造器做了调整，移除了仅接收GcpProjectIdProvider的单参数构造器，强制要求传入PubSubConfiguration参数（注意这里是框架提供的com.google.cloud.spring.pubsub.core.PubSubConfiguration，不是你自定义的配置类）。

修改步骤： #

1. 在mySubscriberFactory方法中注入框架的PubSubConfiguration
   直接将PubSubConfiguration作为方法参数注入，Spring会自动提供这个实例。修改后的代码如下：

import com.google.cloud.spring.pubsub.core.PubSubConfiguration;

@Bean
@Qualifier("mySubscriberFactory")
public DefaultSubscriberFactory mySubscriberFactory(
    GcpProjectIdProvider gcpProjectIdProvider,
    PubSubConfiguration pubSubConfiguration,
    ApplicationProperties applicationProperties
) throws IOException {
    // 使用新的双参数构造器
    final DefaultSubscriberFactory defaultSubscriberFactory = new DefaultSubscriberFactory(gcpProjectIdProvider, pubSubConfiguration);

    var serviceAccountCredentials = ServiceAccountCredentials.fromStream(
        new ByteArrayInputStream(applicationProperties.getGoogleCloudStorage().getAuthentication().getBytes()));

    defaultSubscriberFactory.setCredentialsProvider(FixedCredentialsProvider.create(serviceAccountCredentials));
    return defaultSubscriberFactory;
}

2. 推荐使用Builder模式（更灵活）
   5.x版本也提供了Builder方式来创建DefaultSubscriberFactory，代码更清晰：

import com.google.cloud.spring.pubsub.core.PubSubConfiguration;

@Bean
@Qualifier("mySubscriberFactory")
public DefaultSubscriberFactory mySubscriberFactory(
    GcpProjectIdProvider gcpProjectIdProvider,
    PubSubConfiguration pubSubConfiguration,
    ApplicationProperties applicationProperties
) throws IOException {
    var serviceAccountCredentials = ServiceAccountCredentials.fromStream(
        new ByteArrayInputStream(applicationProperties.getGoogleCloudStorage().getAuthentication().getBytes()));

    return DefaultSubscriberFactory.builder(gcpProjectIdProvider, pubSubConfiguration)
        .credentialsProvider(FixedCredentialsProvider.create(serviceAccountCredentials))
        .build();
}

3. 同步修改DefaultPublisherFactory的构造（可选但建议）
   同样，5.x版本中DefaultPublisherFactory的构造器也做了相同调整，所以你的PubSubTemplate创建代码也需要同步更新：

@Bean
@Qualifier("myPubSubTemplate")
public PubSubTemplate mercareonPubSubTemplate(
    GcpProjectIdProvider gcpProjectIdProvider,
    PubSubConfiguration pubSubConfiguration,
    @Qualifier("mySubscriberFactory") SubscriberFactory subscriberFactory
) {
    DefaultPublisherFactory publisherFactory = new DefaultPublisherFactory(gcpProjectIdProvider, pubSubConfiguration);
    return new PubSubTemplate(publisherFactory, subscriberFactory);
}

注意事项 #

如果你的自定义配置类也叫PubSubConfiguration，为避免类名冲突，注入时可以使用全类名：

@Bean
@Qualifier("mySubscriberFactory")
public DefaultSubscriberFactory mySubscriberFactory(
    GcpProjectIdProvider gcpProjectIdProvider,
    com.google.cloud.spring.pubsub.core.PubSubConfiguration frameworkPubSubConfig,
    ApplicationProperties applicationProperties
) throws IOException {
    final DefaultSubscriberFactory defaultSubscriberFactory = new DefaultSubscriberFactory(gcpProjectIdProvider, frameworkPubSubConfig);
    // ... 其余代码不变
}

内容的提问来源于stack exchange，提问作者Amir Choubani