如何做自己的服务监控？spring boot 2.x服务监控揭秘

Actuator是spring boot项目中非常强大一个功能，有助于对应用程序进行监视和管理，通过 restful api请求来监管、审计、收集应用的运行情况，针对微服务而言它是必不可少的一个环节。

spring 2.x actuator相对于spring 1.x actuator做了较大的改变。

****提供了更多的endpoint管理

ID	Description	Enabled by default
`auditevents`	Exposes audit events information for the current application.	Yes
`beans`	Displays a complete list of all the Spring beans in your application.	Yes
`caches`	Exposes available caches.	Yes
`conditions`	Shows the conditions that were evaluated on configuration and auto-configuration classes and the reasons why they did or did not match.	Yes
`configprops`	Displays a collated list of all `@ConfigurationProperties`.	Yes
`env`	Exposes properties from Spring’s `ConfigurableEnvironment`.	Yes
`flyway`	Shows any Flyway database migrations that have been applied.	Yes
`health`	Shows application health information.	Yes
`httptrace`	Displays HTTP trace information (by default, the last 100 HTTP request-response exchanges).	Yes
`info`	Displays arbitrary application info.	Yes
`integrationgraph`	Shows the Spring Integration graph.	Yes
`loggers`	Shows and modifies the configuration of loggers in the application.	Yes
`liquibase`	Shows any Liquibase database migrations that have been applied.	Yes
`metrics`	Shows ‘metrics’ information for the current application.	Yes
`mappings`	Displays a collated list of all `@RequestMapping` paths.	Yes
`scheduledtasks`	Displays the scheduled tasks in your application.	Yes
`sessions`	Allows retrieval and deletion of user sessions from a Spring Session-backed session store. Not available when using Spring Session’s support for reactive web applications.	Yes
`shutdown`	Lets the application be gracefully shutdown.	No
`threaddump`	Performs a thread dump.	Yes

If your application is a web application (Spring MVC, Spring WebFlux, or Jersey), you can use the following additional endpoints:

ID	Description	Enabled by default
`heapdump`	Returns an `hprof` heap dump file.	Yes
`jolokia`	Exposes JMX beans over HTTP (when Jolokia is on the classpath, not available for WebFlux).	Yes
`logfile`	Returns the contents of the logfile (if `logging.file` or `logging.path` properties have been set). Supports the use of the HTTP `Range` header to retrieve part of the log file’s content.	Yes
`prometheus`	Exposes metrics in a format that can be scraped by a Prometheus server.	Yes

********更多的metrics

JVM metrics, report utilization of:
- Various memory and buffer pools
- Statistics related to garbage collection
- Threads utilization
- Number of classes loaded/unloaded
CPU metrics
File descriptor metrics
Kafka consumer metrics
Log4j2 metrics: record the number of events logged to Log4j2 at each level
Logback metrics: record the number of events logged to Logback at each level
Uptime metrics: report a gauge for uptime and a fixed gauge representing the application’s absolute start time
Tomcat metrics
Spring Integration metrics

*********内部实现也发生了较大的变化，使用micrometer第三方工具来完成metric的实现。下面我们就亲自看看吧！

1.准备源码

https://github.com/tjanusz-personal/springbootrestdemo/tree/master/src/main/java/com/demo/springbootrestdemo

2.导入并启动项目

( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v2.0.4.RELEASE)

2019-01-17 11:20:39.076  INFO 5180 --- [           main] c.d.s.SpringbootrestdemoApplication      : Starting SpringbootrestdemoApplication on DESKTOP-405G2C8 with PID 5180 (E:\document\springbootrestdemo\build\classes\java\main started by dell in E:\document\springbootrestdemo)
2019-01-17 11:20:39.080  INFO 5180 --- [           main] c.d.s.SpringbootrestdemoApplication      : No active profile set, falling back to default profiles: default
2019-01-17 11:20:39.147  INFO 5180 --- [           main] ConfigServletWebServerApplicationContext : Refreshing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@6f01b95f: startup date [Thu Jan 17 11:20:39 CST 2019]; root of context hierarchy
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.springframework.cglib.core.ReflectUtils$1 (file:/D:/gradle/caches/modules-2/files-2.1/org.springframework/spring-core/5.0.8.RELEASE/dc39c49e3246cdf73d3786ac41119140aed3fa08/spring-core-5.0.8.RELEASE.jar) to method java.lang.ClassLoader.defineClass(java.lang.Stri
ng,byte[],int,int,java.security.ProtectionDomain)
WARNING: Please consider reporting this to the maintainers of org.springframework.cglib.core.ReflectUtils$1
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
2019-01-17 11:20:40.341  INFO 5180 --- [           main] trationDelegate$BeanPostProcessorChecker : Bean 'org.springframework.hateoas.config.HateoasConfiguration' of type [org.springframework.hateoas.config.HateoasConfiguration$$EnhancerBySpringCGLIB$$ecf2a812] is not eligible for getting processed by a
ll BeanPostProcessors (for example: not eligible for auto-proxying)
2019-01-17 11:20:40.982  INFO 5180 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
2019-01-17 11:20:41.015  INFO 5180 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2019-01-17 11:20:41.016  INFO 5180 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.32
2019-01-17 11:20:41.029  INFO 5180 --- [ost-startStop-1] o.a.catalina.core.AprLifecycleListener   : The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [D:\software\jdk11\bin;C:\Windows\Sun\Java\bin;C:\Windows\sys
tem32;C:\Windows;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;D:\software\jdk11\bin;D:\software\TortoiseGit\bin;D:\software\Git\cmd;D:\software\apache-maven-3.5.4\bin;D:\software\gradle-4.10.2\bin;D:\software\go\bin;D:\s
oftware\ant\bin;D:\software\anaconda;D:\software\anaconda\Scripts;D:\software\anaconda\Library\bin;C:\Users\dell\AppData\Local\Microsoft\WindowsApps;;.]
2019-01-17 11:20:41.162  INFO 5180 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2019-01-17 11:20:41.168  INFO 5180 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 2035 ms
2019-01-17 11:20:41.832  INFO 5180 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
2019-01-17 11:20:41.832  INFO 5180 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'webMvcMetricsFilter' to: [/*]
2019-01-17 11:20:41.832  INFO 5180 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpTraceFilter' to: [/*]
2019-01-17 11:20:41.833  INFO 5180 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Servlet dispatcherServlet mapped to [/]
2019-01-17 11:20:41.960  INFO 5180 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/saveUrl],methods=[POST],consumes=[application/json;charset=UTF-8 || application/x-www-form-urlencoded],produces=[application/json;charset=UTF-8 || application/xml]}" onto public com.demo.spring
bootrestdemo.domain.response.SaveUrlResponse com.demo.springbootrestdemo.web.DemoController.saveUrl(com.demo.springbootrestdemo.domain.request.SaveUrlRequest,java.lang.String,java.lang.String)
2019-01-17 11:20:41.961  INFO 5180 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/alive],methods=[GET]}" onto public com.demo.springbootrestdemo.domain.response.DemoPingResponse com.demo.springbootrestdemo.web.DemoController.alive()
2019-01-17 11:20:41.964  INFO 5180 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.errorHtml(javax.servlet.http
.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2019-01-17 11:20:41.964  INFO 5180 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.err
or(javax.servlet.http.HttpServletRequest)
2019-01-17 11:20:42.038  INFO 5180 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@6f01b95f: startup date [Thu Jan 17 11:20:39 CST 2019]; root of context hierar
chy
2019-01-17 11:20:42.087  INFO 5180 --- [           main] .m.m.a.ExceptionHandlerExceptionResolver : Detected @ExceptionHandler methods in restResponseEntityExceptionHandler
2019-01-17 11:20:42.529  INFO 5180 --- [           main] o.s.b.a.e.web.EndpointLinksResolver      : Exposing 14 endpoint(s) beneath base path '/actuator'
2019-01-17 11:20:42.538  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator/auditevents],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}" onto public java.lang.Object org.springframework.boot.actuate.endpoint.web.serv
let.AbstractWebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)
2019-01-17 11:20:42.539  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator/beans],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}" onto public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.Ab
stractWebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)
2019-01-17 11:20:42.539  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator/health],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}" onto public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.A
bstractWebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)
2019-01-17 11:20:42.540  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator/conditions],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}" onto public java.lang.Object org.springframework.boot.actuate.endpoint.web.servl
et.AbstractWebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)
2019-01-17 11:20:42.540  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator/configprops],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}" onto public java.lang.Object org.springframework.boot.actuate.endpoint.web.serv
let.AbstractWebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)
2019-01-17 11:20:42.540  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator/env/{toMatch}],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}" onto public java.lang.Object org.springframework.boot.actuate.endpoint.web.se
rvlet.AbstractWebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)
2019-01-17 11:20:42.541  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator/env],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}" onto public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.Abst
ractWebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)
2019-01-17 11:20:42.541  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator/info],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}" onto public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.Abs
tractWebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)
2019-01-17 11:20:42.541  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator/loggers/{name}],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}" onto public java.lang.Object org.springframework.boot.actuate.endpoint.web.s
ervlet.AbstractWebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)
2019-01-17 11:20:42.542  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator/loggers/{name}],methods=[POST],consumes=[application/vnd.spring-boot.actuator.v2+json || application/json]}" onto public java.lang.Object org.springframework.boot.actuate.endpoint.web.
servlet.AbstractWebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)
2019-01-17 11:20:42.542  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator/loggers],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}" onto public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.
AbstractWebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)
2019-01-17 11:20:42.543  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator/heapdump],methods=[GET],produces=[application/octet-stream]}" onto public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.AbstractWebMvcEndpointHandlerMapping$Op
erationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)
2019-01-17 11:20:42.543  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator/threaddump],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}" onto public java.lang.Object org.springframework.boot.actuate.endpoint.web.servl
et.AbstractWebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)
2019-01-17 11:20:42.543  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator/metrics],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}" onto public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.
AbstractWebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)
2019-01-17 11:20:42.544  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator/metrics/{requiredMetricName}],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}" onto public java.lang.Object org.springframework.boot.actuate.
endpoint.web.servlet.AbstractWebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)
2019-01-17 11:20:42.544  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator/scheduledtasks],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}" onto public java.lang.Object org.springframework.boot.actuate.endpoint.web.s
ervlet.AbstractWebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)
2019-01-17 11:20:42.544  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator/httptrace],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}" onto public java.lang.Object org.springframework.boot.actuate.endpoint.web.servle
t.AbstractWebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)
2019-01-17 11:20:42.545  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator/mappings],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}" onto public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet
.AbstractWebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)
2019-01-17 11:20:42.546  INFO 5180 --- [           main] s.b.a.e.w.s.WebMvcEndpointHandlerMapping : Mapped "{[/actuator],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}" onto protected java.util.Map<java.lang.String, java.util.Map<java.lang.String, org.springfr
amework.boot.actuate.endpoint.web.Link>> org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping.links(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2019-01-17 11:20:42.590  INFO 5180 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2019-01-17 11:20:42.641  INFO 5180 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
2019-01-17 11:20:42.648  INFO 5180 --- [           main] c.d.s.SpringbootrestdemoApplication      : Started SpringbootrestdemoApplication in 4.008 seconds (JVM running for 4.517)
<=========----> 75% EXECUTING [25s]
> :bootRun

3.获取EndPoint

3.0 来源

        "webEndpointServletHandlerMapping": {
          "aliases": [
            
          ],
          "scope": "singleton",
          "type": "org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping",
          "resource": "class path resource [org/springframework/boot/actuate/autoconfigure/endpoint/web/servlet/WebMvcEndpointManagementContextConfiguration.class]",
          "dependencies": [
            "webEndpointDiscoverer",
            "servletEndpointDiscoverer",
            "controllerEndpointDiscoverer",
            "endpointMediaTypes",
            "management.endpoints.web.cors-org.springframework.boot.actuate.autoconfigure.endpoint.web.CorsEndpointProperties",
            "management.endpoints.web-org.springframework.boot.actuate.autoconfigure.endpoint.web.WebEndpointProperties"
          ]
        }

spring.factories定义了

org.springframework.boot.actuate.autoconfigure.web.ManagementContextConfiguration=\
org.springframework.boot.actuate.autoconfigure.endpoint.web.ServletEndpointManagementContextConfiguration,\
org.springframework.boot.actuate.autoconfigure.endpoint.web.reactive.WebFluxEndpointManagementContextConfiguration,\
org.springframework.boot.actuate.autoconfigure.endpoint.web.servlet.WebMvcEndpointManagementContextConfiguration,\
org.springframework.boot.actuate.autoconfigure.endpoint.web.jersey.JerseyWebEndpointManagementContextConfiguration,\
org.springframework.boot.actuate.autoconfigure.web.jersey.JerseyManagementChildContextConfiguration,\
org.springframework.boot.actuate.autoconfigure.web.reactive.ReactiveManagementChildContextConfiguration,\
org.springframework.boot.actuate.autoconfigure.web.servlet.ServletManagementChildContextConfiguration,\
org.springframework.boot.actuate.autoconfigure.web.servlet.WebMvcEndpointChildContextConfiguration

3.1 映射

    @Bean
    @ConditionalOnMissingBean
    public WebMvcEndpointHandlerMapping webEndpointServletHandlerMapping(
            WebEndpointsSupplier webEndpointsSupplier,
            ServletEndpointsSupplier servletEndpointsSupplier,
            ControllerEndpointsSupplier controllerEndpointsSupplier,
            EndpointMediaTypes endpointMediaTypes, CorsEndpointProperties corsProperties,
            WebEndpointProperties webEndpointProperties) {
        List<ExposableEndpoint<?>> allEndpoints = new ArrayList<>();
        Collection<ExposableWebEndpoint> webEndpoints = webEndpointsSupplier
                .getEndpoints();
        allEndpoints.addAll(webEndpoints);
        allEndpoints.addAll(servletEndpointsSupplier.getEndpoints());
        allEndpoints.addAll(controllerEndpointsSupplier.getEndpoints());
        EndpointMapping endpointMapping = new EndpointMapping(
                webEndpointProperties.getBasePath());
        return new WebMvcEndpointHandlerMapping(endpointMapping, webEndpoints,
                endpointMediaTypes, corsProperties.toCorsConfiguration(),
                new EndpointLinksResolver(allEndpoints,
                        webEndpointProperties.getBasePath()));
    }

3.2 获取EndPoint

3.2.1 EndPoint定义

/**
 * Identifies a type as being an actuator endpoint that provides information about the
 * running application. Endpoints can be exposed over a variety of technologies including
 * JMX and HTTP.
 * <p>
 * Most {@code @Endpoint} classes will declare one or more
 * {@link ReadOperation @ReadOperation}, {@link WriteOperation @WriteOperation},
 * {@link DeleteOperation @DeleteOperation} annotated methods which will be automatically
 * adapted to the exposing technology (JMX, Spring MVC, Spring WebFlux, Jersey etc.).
 * <p>
 * {@code @Endpoint} represents the lowest common denominator for endpoints and
 * intentionally limits the sorts of operation methods that may be defined in order to
 * support the broadest possible range of exposure technologies. If you need deeper
 * support for a specific technology you can either write an endpoint that is
 * {@link FilteredEndpoint filtered} to a certain technology, or provide
 * {@link EndpointExtension extension} for the broader endpoint.
 *
 * @author Andy Wilkinson
 * @author Phillip Webb
 * @since 2.0.0
 * @see EndpointExtension
 * @see FilteredEndpoint
 * @see EndpointDiscoverer
 */

使用了@Endpoint注解的类

3.2.2 获取所有的EndPoint

    @Override
    public final Collection<E> getEndpoints() {
        if (this.endpoints == null) {
            this.endpoints = discoverEndpoints();
        }
        return this.endpoints;
    }

    private Collection<E> discoverEndpoints() {
        Collection<EndpointBean> endpointBeans = createEndpointBeans();
        addExtensionBeans(endpointBeans);
        return convertToEndpoints(endpointBeans);
    }

    private Collection<EndpointBean> createEndpointBeans() {
        Map<EndpointId, EndpointBean> byId = new LinkedHashMap<>();
        String[] beanNames = BeanFactoryUtils.beanNamesForAnnotationIncludingAncestors(
                this.applicationContext, Endpoint.class);
        for (String beanName : beanNames) {
            if (!ScopedProxyUtils.isScopedTarget(beanName)) {
                EndpointBean endpointBean = createEndpointBean(beanName);
                EndpointBean previous = byId.putIfAbsent(endpointBean.getId(),
                        endpointBean);
                Assert.state(previous == null,
                        () -> "Found two endpoints with the id '" + endpointBean.getId()
                                + "': '" + endpointBean.getBeanName() + "' and '"
                                + previous.getBeanName() + "'");
            }
        }
        return byId.values();
    }

    private EndpointBean createEndpointBean(String beanName) {
        Object bean = this.applicationContext.getBean(beanName);
        return new EndpointBean(beanName, bean);
    }

    private void addExtensionBeans(Collection<EndpointBean> endpointBeans) {
        Map<EndpointId, EndpointBean> byId = endpointBeans.stream()
                .collect(Collectors.toMap(EndpointBean::getId, Function.identity()));
        String[] beanNames = BeanFactoryUtils.beanNamesForAnnotationIncludingAncestors(
                this.applicationContext, EndpointExtension.class);
        for (String beanName : beanNames) {
            ExtensionBean extensionBean = createExtensionBean(beanName);
            EndpointBean endpointBean = byId.get(extensionBean.getEndpointId());
            Assert.state(endpointBean != null,
                    () -> ("Invalid extension '" + extensionBean.getBeanName()
                            + "': no endpoint found with id '"
                            + extensionBean.getEndpointId() + "'"));
            addExtensionBean(endpointBean, extensionBean);
        }
    }

3.3 WebMvcEndpointHandlerMapping

3.3.0 spring mvc的流程复习

其中：

第2步获取HandlerMapping，其层次结构

其中RequestMappingHandlerMapping用来处理@RequestMapping注解

    private RequestMappingInfo createRequestMappingInfo(AnnotatedElement element) {
        RequestMapping requestMapping = AnnotatedElementUtils.findMergedAnnotation(element, RequestMapping.class);
        RequestCondition<?> condition = (element instanceof Class ?
                getCustomTypeCondition((Class<?>) element) : getCustomMethodCondition((Method) element));
        return (requestMapping != null ? createRequestMappingInfo(requestMapping, condition) : null);
    }

第3步获取HandlerAdapter，其层次结构

默认handlerMapping和handlerAdapter定义在DispatcherServlet.properties

org.springframework.web.servlet.HandlerMapping=org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping,\
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping

org.springframework.web.servlet.HandlerAdapter=org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter,\
    org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter,\
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter

3.3.1 获取WebMvcEndpointHandlerMapping

    /**
     * Creates a new {@code WebMvcEndpointHandlerMapping} instance that provides mappings
     * for the given endpoints.
     * @param endpointMapping the base mapping for all endpoints
     * @param endpoints the web endpoints
     * @param endpointMediaTypes media types consumed and produced by the endpoints
     * @param corsConfiguration the CORS configuration for the endpoints or {@code null}
     * @param linksResolver resolver for determining links to available endpoints
     */
    public WebMvcEndpointHandlerMapping(EndpointMapping endpointMapping,
            Collection<ExposableWebEndpoint> endpoints,
            EndpointMediaTypes endpointMediaTypes, CorsConfiguration corsConfiguration,
            EndpointLinksResolver linksResolver) {
        super(endpointMapping, endpoints, endpointMediaTypes, corsConfiguration);
        this.linksResolver = linksResolver;
        setOrder(-100);
    }

父类实现了initHandlerMethods()

    @Override
    protected void initHandlerMethods() {
        for (ExposableWebEndpoint endpoint : this.endpoints) {
            for (WebOperation operation : endpoint.getOperations()) {
                registerMappingForOperation(endpoint, operation);
            }
        }
        if (StringUtils.hasText(this.endpointMapping.getPath())) {
            registerLinksMapping();
        }
    }

将endpoint的Operation映射到Method级别，类似于@RequestMapping

    private void registerMappingForOperation(ExposableWebEndpoint endpoint,
            WebOperation operation) {
        ServletWebOperation servletWebOperation = wrapServletWebOperation(endpoint,
                operation, new ServletWebOperationAdapter(operation));
        registerMapping(createRequestMappingInfo(operation),
                new OperationHandler(servletWebOperation), this.handleMethod);
    }

    /**
     * Hook point that allows subclasses to wrap the {@link ServletWebOperation} before
     * it's called. Allows additional features, such as security, to be added.
     * @param endpoint the source endpoint
     * @param operation the source operation
     * @param servletWebOperation the servlet web operation to wrap
     * @return a wrapped servlet web operation
     */
    protected ServletWebOperation wrapServletWebOperation(ExposableWebEndpoint endpoint,
            WebOperation operation, ServletWebOperation servletWebOperation) {
        return servletWebOperation;
    }

    private RequestMappingInfo createRequestMappingInfo(WebOperation operation) {
        WebOperationRequestPredicate predicate = operation.getRequestPredicate();
        PatternsRequestCondition patterns = patternsRequestConditionForPattern(
                predicate.getPath());
        RequestMethodsRequestCondition methods = new RequestMethodsRequestCondition(
                RequestMethod.valueOf(predicate.getHttpMethod().name()));
        ConsumesRequestCondition consumes = new ConsumesRequestCondition(
                StringUtils.toStringArray(predicate.getConsumes()));
        ProducesRequestCondition produces = new ProducesRequestCondition(
                StringUtils.toStringArray(predicate.getProduces()));
        return new RequestMappingInfo(null, patterns, methods, null, null, consumes,
                produces, null);
    }

3.3.2 获取ServletWebOperationAdapter

AbstractWebMvcEndpointHandlerMapping$OperationHandler.handle

        @Override
        public Object handle(HttpServletRequest request,
                @RequestBody(required = false) Map<String, String> body) {
            Map<String, Object> arguments = getArguments(request, body);
            try {
                return handleResult(
                        this.operation.invoke(new InvocationContext(
                                new ServletSecurityContext(request), arguments)),
                        HttpMethod.valueOf(request.getMethod()));
            }
            catch (InvalidEndpointRequestException ex) {
                throw new BadOperationRequestException(ex.getReason());
            }
        }

4.触发机制

If you add a @Bean annotated with @Endpoint, any methods annotated with @ReadOperation, @WriteOperation, or @DeleteOperation are automatically exposed over JMX and, in a web application, over HTTP as well. Endpoints can be exposed over HTTP using Jersey, Spring MVC, or Spring WebFlux.

if you need access to web-framework-specific functionality, you can implement Servlet or Spring @Controller and @RestController endpoints at the cost of them not being available over JMX or when using a different web framework.

EndpointDiscoverer

    @Override
    public final Collection<E> getEndpoints() {
        if (this.endpoints == null) {
            this.endpoints = discoverEndpoints();
        }
        return this.endpoints;
    }

    private Collection<E> discoverEndpoints() {
        Collection<EndpointBean> endpointBeans = createEndpointBeans();
        addExtensionBeans(endpointBeans);
        return convertToEndpoints(endpointBeans);
    }

调用 @ReadOperation, @WriteOperation, or @DeleteOperation方法

    private void addOperations(MultiValueMap<OperationKey, O> indexed, EndpointId id,
            Object target, boolean replaceLast) {
        Set<OperationKey> replacedLast = new HashSet<>();
        Collection<O> operations = this.operationsFactory.createOperations(id, target);
        for (O operation : operations) {
            OperationKey key = createOperationKey(operation);
            O last = getLast(indexed.get(key));
            if (replaceLast && replacedLast.add(key) && last != null) {
                indexed.get(key).remove(last);
            }
            indexed.add(key, operation);
        }
    }

其中DiscoveredOperationsFactory定义了@ReadOperation, @WriteOperation, or @DeleteOperation方法

    private static final Map<OperationType, Class<? extends Annotation>> OPERATION_TYPES;

    static {
        Map<OperationType, Class<? extends Annotation>> operationTypes = new EnumMap<>(
                OperationType.class);
        operationTypes.put(OperationType.READ, ReadOperation.class);
        operationTypes.put(OperationType.WRITE, WriteOperation.class);
        operationTypes.put(OperationType.DELETE, DeleteOperation.class);
        OPERATION_TYPES = Collections.unmodifiableMap(operationTypes);
    }

    private final ParameterValueMapper parameterValueMapper;

    private final Collection<OperationInvokerAdvisor> invokerAdvisors;

    DiscoveredOperationsFactory(ParameterValueMapper parameterValueMapper,
            Collection<OperationInvokerAdvisor> invokerAdvisors) {
        this.parameterValueMapper = parameterValueMapper;
        this.invokerAdvisors = invokerAdvisors;
    }

    public Collection<O> createOperations(EndpointId id, Object target) {
        return MethodIntrospector.selectMethods(target.getClass(),
                (MetadataLookup<O>) (method) -> createOperation(id, target, method))
                .values();
    }

    private O createOperation(EndpointId endpointId, Object target, Method method) {
        return OPERATION_TYPES.entrySet().stream()
                .map((entry) -> createOperation(endpointId, target, method,
                        entry.getKey(), entry.getValue()))
                .filter(Objects::nonNull).findFirst().orElse(null);
    }

总结：

1.若一个Bean在类上使用@Endpoint注解，并且在方法上使用@ReadOperation, @WriteOperation, or @DeleteOperation注解，那么自动可以使用jmx或者http访问，http提供服务的可以是Jersey, Spring MVC或者Spring WebFlux.

2.http提供服务的基本机制

2.1 使用HandlerMapping映射请求
2.2 使用HandlerAdapter(自定义)聚合EndPoint，并代理EndPoint的请求。

参考文献

【1】https://terasolunaorg.github.io/guideline/1.0.x/en/Overview/SpringMVCOverview.html

【2】https://docs.spring.io/spring-boot/docs/2.1.2.RELEASE/reference/htmlsingle/#production-ready-enabling

posted on 2019-01-22 17:28 一天不进步，就是退步阅读(2752) 评论(0) 编辑收藏举报