spring 从非 bean 访问代理 bean class

Question

我有一个 spring bean，它在其方法上使用 dropwizard-metrics 注释来测量某些指标（参见 #parse 方法）：

@Component
public class Consumer extends AbstractConsumer {

  @Autowired
  private EventsService eventsService;

  private ExecutorService executor;

  @PostConstruct
  void init() throws Exception {
    executor = Executors.newFixedThreadPool(1);

    ConsumerEventsHandler consumer = new ConsumerEventsHandler(Arrays.asList("topic1"), this);
    executor.submit(consumer);
  }

  @Timed(name = CONSUMER_BATCH_PARSING_TIME, absolute = true)
  public void parse(ConsumerRecord<String, String> record) {
    String val = record.value();
    eventsService.parseToDB(val);
  }
}

如您所见，此 bean 向执行程序服务提交了一个新任务，该任务不是一个 bean，但它需要引用 Consumer bean 以重用其逻辑（请参阅consumer.parse(记录);调用:

public class ConsumerEventsHandler implements Runnable {

private Consumer consumer;
private List<String> topics;
protected final KafkaConsumer<String, String> kafkaConsumer;

public ConsumerEventsHandler(List<String> topics, Consumer consumer) {
    this.topics = topics;
    this.consumer = consumer;
    this.kafkaConsumer = new KafkaConsumer<>();
}

@Override
public void run() {
    try {
        consumer.subscribe(topics);
        while (true) {
            ConsumerRecords<String, String> records = consumer.poll(Long.MAX_VALUE);

            for (ConsumerRecord<String, String> record : records) {
                consumer.parse(record);
            }
        }
    } finally {
        consumer.close();
    }
}

}

这是指标配置（我使用 'ryantenney/metrics-spring' 库）：

@Configuration
@EnableMetrics(proxyTargetClass = true)
@ComponentScan(basePackages = "com.inq")
public class SsvpApiMetricsConfig extends MetricsConfigurerAdapter {
  @Resource
  private MetricRegistry registry;

  @PostConstruct()
  public void init() {
    configureReporters(registry);
  }

  @Override
  public void configureReporters(MetricRegistry metricRegistry) {

    registerReporter(JmxReporter.forRegistry(metricRegistry).
       inDomain("com.inq.metrics").build()).start();
  }
}

结果，我看到 Consumer bean 被代理了，但是 ConsumerEventsHandler 包含对普通 bean 的引用，因为它在创建时在 Consumer 的 @PostConstruct 方法中，通过 'new ConsumerEventsHandler(..)' Consumer bean 尚未被代理，我假设在代理事物之前调用了 @PostConstruct。

我看到的唯一解决方法是每次在#运行方法中通过 ApplicationContext#getBean 获取 Consumer bean ref，而不是将 ref 存储在 ConsumerEventsHandler class 变量。还有其他解决方案吗？

Answer 1

只需在非 spring class

上创建静态

public class ConsumerEventsHandler implements Runnable {

private static Consumer consumer;
private List<String> topics;
protected final KafkaConsumer<String, String> kafkaConsumer;

public ConsumerEventsHandler(List<String> topics) {
    this.topics = topics;
    this.kafkaConsumer = new KafkaConsumer<>();
}

public static setConsumer(Consumer consumer) {
    ConsumerEventsHandler.consumer = consumer;
}

那么在你的spring这边你可以有：

  @PostConstruct()
  public void init() {
    configureReporters(registry);
    ConsumerEventsHandler.setConsumer(consumer);
  }

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