Spring Boot 存储库指标

Question

我正在尝试在 SpringBoot 中创建一个对象 repositoryMetrics，后来我通过这个存储库获得了信息。但我创建了一个存储库，它始终为空。

如何生成存储库并保存指标？ 我有这个代码：

public static void stateSist() throws Exception {

    InMemoryMetricRepository metricRepository = null;
    metricRepository.findAll();
    System.out.println(metricRepository.count());

}

编辑 1：

我在我的版本中做了这个改变，我得到了这个错误：

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'actuatorMetricsPrinter' defined in file [ActuatorMetricsPrinter.class]: Unsatisfied dependency expressed through constructor argument with index 0 of type [java.util.Collection]: : No qualifying bean of type [org.springframework.boot.actuate.endpoint.PublicMetrics] found for dependency [collection of org.springframework.boot.actuate.endpoint.PublicMetrics]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.boot.actuate.endpoint.PublicMetrics] found for dependency [collection of org.springframework.boot.actuate.endpoint.PublicMetrics]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:747)
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:185)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1115)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1018)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:504)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:706)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:762)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:109)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:691)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:320)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:952)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:941)
at hello.Application.main(Application.java:14)
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.boot.actuate.endpoint.PublicMetrics] found for dependency [collection of org.springframework.boot.actuate.endpoint.PublicMetrics]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}
at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1118)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:919)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:862)
at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:811)
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:739)
... 18 common frames omitted

谢谢！

Answer 1

为了访问 Spring Boot 执行器框架打印的所有公共指标，您需要将“集合”注入到您的组件中，然后访问它以读取所有指标。这是一个例子：

    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.actuate.endpoint.PublicMetrics;
    import org.springframework.boot.actuate.metrics.Metric;
    import org.springframework.stereotype.Component;

    import java.util.Collection;

    @Component
    public class ActuatorMetricsPrinter {
        private static final String TEMPLATE = "Metric: %s [%s]";

        private final Collection<PublicMetrics> publicMetrics;

        @Autowired
        public ActuatorMetricsPrinter(Collection<PublicMetrics> publicMetrics) {
            this.publicMetrics = publicMetrics;
        }

        public String printAllMetrics() {

            StringBuilder sb = new StringBuilder();

            for (PublicMetrics pm : publicMetrics) {
                sb.append("Public Metric: " + pm.getClass().getName());
                sb.append("\n\n");

                for (Metric<?> m : pm.metrics()) {
                    sb.append(String.format(TEMPLATE, m.getName(), m.getValue().toString()));
                    sb.append("\n");
                }
            }

            return sb.toString();
        }
    }

如果你想重现这个简单的场景，那么：

1. 转到 http://start.spring.io/ 并创建新项目，并检查 Actuator 和 Web，
2. 使用您选择的构建工具（Gradle、Maven）创建一个演示项目，
3. 下载并在您的 IDE 中打开，
4. 创建一个新组件，就像我的示例中的一样，
5. 创建一个新的 RestController，如下所示：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class DummyController {

    private final ActuatorMetricsPrinter metricsPrinter;

    @Autowired
    public DummyController(ActuatorMetricsPrinter metricsPrinter) {
        this.metricsPrinter = metricsPrinter;
    }

    @RequestMapping(value = "/customMetrics", method = RequestMethod.GET)
    public String printMetrics() {
        return metricsPrinter.printAllMetrics();
    }
}

6. 然后启动应用程序并在浏览器中输入：http://localhost:8080/customMetrics
7. 你应该看到你的班级以最混乱的方式打印的所有指标

Answer 2

如果您使用 Maven 或 Gradle 进行依赖管理，那么您必须确保它们存在于其中（来自Spring Clouds's Home Page）：

Maven：

<parent>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-parent</artifactId>
    <version>Angel.SR4</version>
</parent>
<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-config</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-eureka</artifactId>
    </dependency>
</dependencies>

Gradle：

buildscript {
  dependencies {
    classpath "io.spring.gradle:dependency-management-plugin:0.4.0.RELEASE"
  }
}

apply plugin: "io.spring.dependency-management"

dependencyManagement {
  imports {
    mavenBom 'org.springframework.cloud:spring-cloud-starter-parent:Angel.SR4'
  }
}

dependencies {
    compile 'org.springframework.cloud:spring-cloud-starter-config'
    compile 'org.springframework.cloud:spring-cloud-starter-eureka'
}

如果您在 Maven 中省略 parent 或在 gradle 中省略 dependencyManagement，并尝试仅导入每个依赖项的最新版本，您将收到您所描述的运行时错误。

类似的问题解决了 GitHub 上的 here。