如何让 spring 中的 prometheus webflux r2dbc 协同工作？当我尝试 运行 来自服务的实际 api 时，它给了我错误

Question

我在 spring-boot2 中使用 prometheus 生成指标，我正在使用 webflux 和 r2dbc 库进行反应式编程，但是我不确定它们是否可以协同工作。请帮助我理解我做错了什么。

它给出以下错误

java.lang.NoSuchMethodError: org.springframework.transaction.reactive.TransactionSynchronizationManager.currentTransaction()Lreactor/core/publisher/Mono;
    at org.springframework.data.r2dbc.connectionfactory.ConnectionFactoryUtils.doGetConnection(ConnectionFactoryUtils.java:88) ~[spring-data-r2dbc-1.0.0.M2.jar:1.0.0.M2]   at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:605) ~[spring-data-commons-2.2.3.RELEASE.jar:2.2.3.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.2.RELEASE.jar:5.2.2.RELEASE]
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93) ~[spring-aop-5.2.2.RELEASE.jar:5.2.2.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.2.RELEASE.jar:5.2.2.RELEASE]
    at org.springframework.data.repository.core.support.MethodInvocationValidator.invoke(MethodInvocationValidator.java:99) ~[spring-data-commons-2.2.3.RELEASE.jar:2.2.3.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.2.RELEASE.jar:5.2.2.RELEASE]
    at 

我的 build.gradle 看起来像这样：

 plugins {    
        id("org.springframework.boot") version "2.2.2.RELEASE",
        id ("io.spring.dependency-management") version "1.0.8.RELEASE"
     }
   dependencies {
       implementation ("org.springframework.boot.experimental:spring-boot-starter-r2dbc")
       implementation ("org.springframework.boot.experimental:spring-boot-starter-data-r2dbc")
       implementation ("org.springframework.boot:spring-boot-starter")
       implementation("org.springframework.boot:spring-boot-starter-actuator")
       implementation("io.micrometer:micrometer-registry-prometheus")
       implementation ("org.springframework.boot:spring-boot-starter-webflux")
       testImplementation ("io.projectreactor:reactor-test")
  }

控制器函数如下所示：

@Timed(histogram = true )
@GetMapping("/abc")
fun process(@PathVariable ab: String): Mono<xyz> {
    return service.getXYZ(xyz)
 }

Answer 1

当使用 spring 初始化程序生成新项目时，它将为您提供以下依赖项：

dependencies {
    implementation 'org.springframework.boot.experimental:spring-boot-actuator-autoconfigure-r2dbc'
    implementation 'org.springframework.boot:spring-boot-starter-actuator'
    implementation 'org.springframework.boot.experimental:spring-boot-starter-data-r2dbc'
    implementation 'org.springframework.boot:spring-boot-starter-webflux'
    testImplementation('org.springframework.boot:spring-boot-starter-test') {
        exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'
    }
    testImplementation 'org.springframework.boot.experimental:spring-boot-test-autoconfigure-r2dbc'
    testImplementation 'io.projectreactor:reactor-test'
}

您似乎缺少 spring-boot-actuator-autoconfigure-r2dbc，您可以删除

implementation ("org.springframework.boot.experimental:spring-boot-starter-r2dbc")

因为 spring-boot-starter-data-r2dbc 将引入其传递依赖项。

由于 R2DBC 仍处于实验阶段，其自动配置尚未合并到 spring 引导中，必须单独包含。我已经向开发人员提出了一个问题，并要求现在这部分应该在官方文档中提及。