Java 为什么SpringBoot从2.3.0升级到2.5.0无法启动tomcat，普罗米修斯例外？

以前的SpringBoot升级都是无痛的，但是我们的2.5.0升级并没有开始。以下是异常的排序版本：

Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'webMvcMetricsFilter' defined in class path resource [org/springframework/boot/actuate/autoconfigure/metrics/web/servlet/WebMvcMetricsAutoConfiguration.class]: Unsatisfied dependency expressed through method 'webMvcMetricsFilter' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'prometheusMeterRegistry' defined in class path resource [org/springframework/boot/actuate/autoconfigure/metrics/export/prometheus/PrometheusMetricsExportAutoConfiguration.class]: Unsatisfied dependency expressed through method 'prometheusMeterRegistry' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'prometheusConfig' defined in class path resource [org/springframework/boot/actuate/autoconfigure/metrics/export/prometheus/PrometheusMetricsExportAutoConfiguration.class]: Unsatisfied dependency expressed through method 'prometheusConfig' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'management.metrics.export.prometheus-org.springframework.boot.actuate.autoconfigure.metrics.export.prometheus.PrometheusProperties': Lookup method resolution failed; nested exception is java.lang.IllegalStateException: Failed to introspect Class [org.springframework.boot.actuate.autoconfigure.metrics.export.prometheus.PrometheusProperties] from ClassLoader [org.springframework.boot.loader.LaunchedURLClassLoader@7c0e2abd]

最后一个例外似乎造成了这场混乱：

Caused by: java.lang.IllegalStateException: Failed to introspect Class [org.springframework.boot.actuate.autoconfigure.metrics.export.prometheus.PrometheusProperties] from ClassLoader [org.springframework.boot.loader.LaunchedURLClassLoader@7c0e2abd]
        at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:481)
        at org.springframework.util.ReflectionUtils.doWithLocalMethods(ReflectionUtils.java:321)
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.determineCandidateConstructors(AutowiredAnnotationBeanPostProcessor.java:267)
        ... 103 common frames omitted
Caused by: java.lang.NoClassDefFoundError: io/micrometer/prometheus/HistogramFlavor
        at java.base/java.lang.Class.getDeclaredMethods0(Native Method)
        at java.base/java.lang.Class.privateGetDeclaredMethods(Class.java:3244)
        at java.base/java.lang.Class.getDeclaredMethods(Class.java:2387)
        at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:463)
        ... 105 common frames omitted
Caused by: java.lang.ClassNotFoundException: io.micrometer.prometheus.HistogramFlavor
        at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:435)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:590)
        at org.springframework.boot.loader.LaunchedURLClassLoader.loadClass(LaunchedURLClassLoader.java:129)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:523)
        ... 109 common frames omitted

---

我找到了这个参考资料：，事实上，这个项目包括了答案中提到的致动器和测微计的依赖关系。我最初并没有设置它，所以组件之间的相互作用，或者人们通常是如何对这类事情进行故障诊断和修复的，我并不十分清楚。

从由引起的

来看，测微计dependecny缺少或不是正确的版本，您需要将其添加到项目的pom.xml中。测微计是一个维度优先的度量集合外观，其目的是允许您使用与供应商无关的AP对代码进行计时、计数和度量

<dependency>
    <groupId>io.micrometer</groupId>
    <artifactId>micrometer-spring-legacy</artifactId>
    <version>1.5.1</version>
</dependency>


千分尺
千分尺弹簧
1.5.1
如上所述，它已经依赖测微计（版本为1.3.2）和弹簧启动启动器执行器（未指定版本）。我修改了版本，但还是同样的错误。