深入解析com.codahale.metrics.servlets.AdminServlet.()方法及其应用实例

本文详细介绍了 Java 中 com.codahale.metrics.servlets.AdminServlet.() 方法的使用场景和具体实现方式。通过分析来自 Github、Stackoverflow 和 Maven 等平台上的多个实际项目中的代码片段，本文为读者提供了丰富的参考资料，旨在帮助开发者更好地理解并利用 AdminServlet.() 方法。

AdminServlet. 方法概述

AdminServlet.() 是一个构造函数，用于初始化 AdminServlet 类的实例。该类通常用于提供系统管理和监控功能，如健康检查、性能指标展示等。通过配置不同的参数和监听器，可以实现对应用状态的全面监控。

代码示例

示例 1 - 来源：twitter/distributedlog

public void start() throws Exception {
  ServletContextHandler cOntext= new ServletContextHandler(ServletContextHandler.SESSIONS);
  context.setContextPath("/");
  jettyServer.setHandler(context);
  context.addEventListener(new HealthCheckServletContextListener(healthCheckRegistry));
  context.addEventListener(new MetricsServletContextListener(metricRegistry));
  context.addServlet(new ServletHolder(new AdminServlet()), "/*");
  jettyServer.start();
}

示例 2 - 来源：dropwizard/dropwizard

protected Handler createAdminServlet(Server server,
                   MutableServletContextHandler handler,
                   MetricRegistry metrics,
                   HealthCheckRegistry healthChecks) {
  configureSessionsAndSecurity(handler, server);
  handler.setServer(server);
  handler.getServletContext().setAttribute(MetricsServlet.METRICS_REGISTRY, metrics);
  handler.getServletContext().setAttribute(HealthCheckServlet.HEALTH_CHECK_REGISTRY, healthChecks);
  handler.addServlet(new NonblockingServletHolder(new AdminServlet()), "/*");
  final String allowedMethodsParam = allowedMethods.stream()
      .collect(Collectors.joining(","));
  handler.addFilter(AllowedMethodsFilter.class, "/*", EnumSet.of(DispatcherType.REQUEST))
      .setInitParameter(AllowedMethodsFilter.ALLOWED_METHODS_PARAM, allowedMethodsParam);
  return handler;
}

示例 3 - 来源：io.dropwizard/dropwizard-core

protected Handler createAdminServlet(Server server,
                   MutableServletContextHandler handler,
                   MetricRegistry metrics,
                   HealthCheckRegistry healthChecks) {
  configureSessionsAndSecurity(handler, server);
  handler.setServer(server);
  handler.getServletContext().setAttribute(MetricsServlet.METRICS_REGISTRY, metrics);
  handler.getServletContext().setAttribute(HealthCheckServlet.HEALTH_CHECK_REGISTRY, healthChecks);
  handler.addServlet(new NonblockingServletHolder(new AdminServlet()), "/*");
  handler.addFilter(AllowedMethodsFilter.class, "/*", EnumSet.of(DispatcherType.REQUEST))
      .setInitParameter(AllowedMethodsFilter.ALLOWED_METHODS_PARAM, Joiner.on(',').join(allowedMethods));
  return handler;
}

示例 4 - 来源：com.opentable.components/otj-metrics-core

@Bean
public ServletRegistrationBean getMetricsServlet() {
  return new ServletRegistrationBean<>(new AdminServlet(), path + "/*");
}

示例 5 - 来源：stackoverflow.com

@Bean
public ServletRegistrationBean servletRegistrationBean(){
  return new ServletRegistrationBean(new AdminServlet(),"/metrics/admin/*");
}

示例 6 - 来源：stackoverflow.com

@Bean
public ServletRegistrationBean axisServletRegistrationBean() {
  ServletRegistrationBean registration = new ServletRegistrationBean(new AxisServlet(), "/services/*");
  registration.addUrlMappings("*.jws");
  return registration;
}
@Bean
public ServletRegistrationBean adminServletRegistrationBean() {
  return new ServletRegistrationBean(new AdminServlet(), "/servlet/AdminServlet");
}

示例 7 - 来源：org.apache.distributedlog/distributedlog-service

public void start() throws Exception {
  ServletContextHandler cOntext= new ServletContextHandler(ServletContextHandler.SESSIONS);
  context.setContextPath("/");
  jettyServer.setHandler(context);
  context.addEventListener(new HealthCheckServletContextListener(healthCheckRegistry));
  context.addEventListener(new MetricsServletContextListener(metricRegistry));
  context.addServlet(new ServletHolder(new AdminServlet()), "/*");
  jettyServer.start();
}

示例 8 - 来源：airbnb/billow

adminHandler.addServlet(new ServletHolder(new AdminServlet()), "/*");

示例 9 - 来源：Kixeye/chassis

context.getServletContext().setAttribute(HealthCheckServlet.HEALTH_CHECK_REGISTRY, healthCheckRegistry);
ServletHolder holder = new ServletHolder(new AdminServlet());
holder.setInitParameter("service-name", System.getProperty("app.name"));
context.addServlet(holder, "/metrics/*");

示例 10 - 来源：stackoverflow.com

public class YourApplication extends Application {
  // ...
  @Override
  public void run(YourConfiguration configuration, Environment environment) throws Exception {
    environment.jersey().register(new MyResource());
    environment.getApplicationContext().setAttribute(
        MetricsServlet.METRICS_REGISTRY,
        environment.metrics());
    environment.getApplicationContext().setAttribute(
        HealthCheckServlet.HEALTH_CHECK_REGISTRY,
        environment.healthChecks());
    environment.getApplicationContext().addServlet(
        new NonblockingServletHolder(new AdminServlet()), "/admin/*");
  }
}

示例 11 - 来源：apache/lens

.setAttribute("com.codahale.metrics.servlets.MetricsServlet.registry", (metricsService.getMetricRegistry()));
adminCtx.setAttribute("com.codahale.metrics.servlets.HealthCheckServlet.registry", metricsService.getHealthCheck());
final ServletRegistration sgMetrics = adminCtx.addServlet("admin", new AdminServlet());
sgMetrics.addMapping("/admin/*");
adminCtx.deploy(server);