升级到spring boot 2.6.7导致循环依赖

Question

我正在将我的项目从 springboot 2.4.4 升级到 2.6.7，但是在较新的版本中，由于循环依赖，我遇到了这个运行时错误：

***************************
APPLICATION FAILED TO START
***************************

Description:

The dependencies of some of the beans in the application context form a cycle:

   webMvcMetricsFilter defined in class path resource [org/springframework/boot/actuate/autoconfigure/metrics/web/servlet/WebMvcMetricsAutoConfiguration.class]
┌─────┐
|  prometheusMeterRegistry defined in class path resource [org/springframework/boot/actuate/autoconfigure/metrics/export/prometheus/PrometheusMetricsExportAutoConfiguration.class]
↑     ↓
|  meterRegistryConfig defined in URL [jar:file:/Users/myname/Documents/repo/myrepo/my-module/bin/my-module.jar!/com/mypackage/app/metrics/MeterRegistryConfig.class]
└─────┘

这是我的 MeterRegistryConfig class:

import io.micrometer.core.instrument.Meter;
import io.micrometer.core.instrument.MeterRegistry;
import io.micrometer.core.instrument.config.MeterFilter;
import io.micrometer.core.instrument.distribution.DistributionStatisticConfig;
import org.jetbrains.annotations.NotNull;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

@Component
public class MeterRegistryConfig implements MeterFilter {

  @Autowired
  public MeterRegistryConfig(final MeterRegistry registry) {
    registry
        .config()
        .meterFilter(
            new MeterFilter() {
              @Override
              public DistributionStatisticConfig configure(
                  @NotNull final Meter.Id id, @NotNull final DistributionStatisticConfig config) {
                return DistributionStatisticConfig.builder()
                    .percentilesHistogram(true)
                    .percentilePrecision(3)
                    .build()
                    .merge(config);
              }
            });
  }
}

我不确定为什么这种循环依赖会发生在新版本而不是旧版本上。谁能帮我解决一下？

Answer 1

Spring 引导会自动将每个 MeterFilter bean 添加到 auto-configured MeterRegistry，因此不需要当前形式的 MeterRegistryConfig。我将用定义 MeterFilter bean 的 @Configuration class 替换它。像这样：

import io.micrometer.core.instrument.Meter;
import io.micrometer.core.instrument.config.MeterFilter;
import io.micrometer.core.instrument.distribution.DistributionStatisticConfig;
import org.jetbrains.annotations.NotNull;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
class MeterRegistryConfig {

    @Bean
    MeterFilter yourMeterFilter() {
        return new MeterFilter() {
            @Override
            public DistributionStatisticConfig configure(
                    @NotNull final Meter.Id id,
                    @NotNull final DistributionStatisticConfig config) {
                return DistributionStatisticConfig.builder()
                    .percentilesHistogram(true)
                    .percentilePrecision(3)
                    .build()
                    .merge(config);
            }
        };
    }

}

升级到spring boot 2.6.7导致循环依赖

Upgrading to springboot 2.6.7 leads to cyclic dependency

java

cyclic-dependency

spring-boot

prometheus

micrometer