SpringCloud之Resilience4j相关配置信息

# 1.resilience4j涉及的相关配置类

public class CommonProperties {

    Map<String, String> tags = new HashMap<>();
    public Map<String, String> getTags() {
        return tags;
    }
    public void setTags(Map<String, String> tags) {
        this.tags = tags;
    }
}

父类CommonProperties涉及的子类包含RateLimiterConfigurationProperties、CircuitBreakerConfigurationProperties、RetryConfigurationProperties、TimeLimiterConfigurationProperties等。

## 1.1.熔断器相关配置
通过`CircuitBreakerConfiguration`初始化类`CircuitBreakerRegistry`，该类存储了全部CircuitBreaker实例。并且CircuitBreaker实例所需的配置信息是通过`CommonProperties的子类`转化为`CircuitBreakerConfig`后得到的。

> 类CircuitBreakerConfig存在的配置项只是CommonProperties的子类中部分配置项内容。

public class CircuitBreakerConfigurationProperties extends CommonProperties {
	  //这个是可以针对特定业务线配置，但是其name值如下图中ID属性值。目前本人尚未解决是否可以简化name值的套路
    private Map<String, InstanceProperties> instances = new HashMap<>();
    private Map<String, InstanceProperties> configs = new HashMap<>();

    public Optional<InstanceProperties> findCircuitBreakerProperties(String name) {
        InstanceProperties instanceProperties = instances.get(name);
        if (instanceProperties == null) {
            instanceProperties = configs.get("default");
        }
        return Optional.ofNullable(instanceProperties);
    }

    public CircuitBreakerConfig createCircuitBreakerConfig(String backendName,
        InstanceProperties instanceProperties,
        CompositeCustomizer<CircuitBreakerConfigCustomizer> compositeCircuitBreakerCustomizer) {
        if (StringUtils.isNotEmpty(instanceProperties.getBaseConfig())) {
            InstanceProperties baseProperties = configs.get(instanceProperties.getBaseConfig());
            if (baseProperties == null) {
                throw new ConfigurationNotFoundException(instanceProperties.getBaseConfig());
            }
            return buildConfigFromBaseConfig(instanceProperties, baseProperties,
                compositeCircuitBreakerCustomizer,
                backendName);
        }
        return buildConfig(custom(), instanceProperties, compositeCircuitBreakerCustomizer,
            backendName);
    }
}

?

如上配置初始化过程只是将公共配置项复制到最终的CircuitBreakerConfig中，在属性configs中还是配置文件中配置的原始内容。

resilience4j:
  timelimiter:
    configs:
      default:
        timeoutDuration: 1s
  circuitbreaker:
    configs:
      myfans:
        baseConfig: common // 公共配置项
        registerHealthIndicator: true // 独有配置项
      default:
        baseConfig: common
        registerHealthIndicator: true // 独有配置项
      common:
        minimumNumberOfCalls: 3
        slidingWindowSize: 10
        automaticTransitionFromOpenToHalfOpenEnabled: true

如上所示，即类CircuitBreakerConfigurationProperties中configs属性中对应三个名为myfans、default、common的配置项内容。初始化CircuitBreakerConfig中配置时并不会将common中内容添加到myfans、default中。