使用Guice和Embedded jetty配置codahale MetricsServlet

Question

我似乎無法正確設置Metrics servlet。它的404。我使用Guice 3.0，嵌入式Jetty 9和Metrics 3.0.1。這裏就是我設置Jetty服務器：

public void start() { 
    //start jetty 
    _server = new Server(_port); 
    ResourceHandler resourceHandler = new ResourceHandler(); 
    resourceHandler.setDirectoriesListed(true); 
    resourceHandler.setWelcomeFiles(new String[]{"index.html"}); 
    resourceHandler.setResourceBase("."); 
    HandlerList handlers = new HandlerList(); 
    ServletContextHandler guiceHandler = new ServletContextHandler(); 
    guiceHandler.addEventListener(_metricsServletContextListener); 
    guiceHandler.setContextPath("/rest"); 
    guiceHandler.addServlet(new ServletHolder(new MetricsServlet(_metricRegistry)), "/metrics"); 
    FilterHolder guiceFilter = new FilterHolder(_filter); 
    guiceHandler.addFilter(guiceFilter, "/*", EnumSet.allOf(DispatcherType.class)); 
    handlers.setHandlers(new Handler[]{guiceHandler, resourceHandler}); 
    _server.setHandler(handlers); 
    _server.setDumpAfterStart(true); 
    try { 
     _server.start(); 
    }catch(Exception ex) { 
     log.error("Error starting http server", ex); 
     throw new RuntimeException(ex); 
    } 
    log.info("one id http service started, doc base: {}, URI: {}", resourceHandler.getResourceBase(), _server.getURI()); 
} 

這裏的ContextListener擴展：

public class MetricsServletContextListener extends MetricsServlet.ContextListener { 
    private MetricRegistry _metricRegistry; 

    public MetricsServletContextListener(MetricRegistry metricRegistry) { 
     _metricRegistry = metricRegistry; 
    } 

    @Override 
    protected MetricRegistry getMetricRegistry() { 
     return _metricRegistry; 
    } 
} 

如果我打http://localhost:8080/rest/metrics，它404的。看到碼頭啓動日誌，該servlet得到創建的，似乎是高達：

+= org.eclipse.jetty.server.handler.HandlerList@766adae2 - STARTED 
| += o.e.j.s.ServletContextHandler@478e3145{/rest,null,AVAILABLE} - STARTED 
| | += org.eclipse.jetty.servlet.ServletHandler@40542fa7 - STARTED 
| | | += com.codahale.metrics.servlets.MetricsServlet- 299abf92@b8bee068==com.codahale.metrics.servlets.MetricsServlet,-1,true - STARTED 
| | | +- [/metrics]=>com.codahale.metrics.servlets.MetricsServlet-299abf92 
| | | += com.google.inject.servlet.GuiceFilter-5baef385 - STARTED 

Answer 1

添加MetricsServlet到它自己的ServletContextHandler和註冊MetricsServlet.ContextListener的實現固定它。

_server = new Server(_port); 
    ResourceHandler resourceHandler = new ResourceHandler(); 
    resourceHandler.setDirectoriesListed(true); 
    resourceHandler.setWelcomeFiles(new String[]{"index.html"}); 
    resourceHandler.setResourceBase("."); 
    HandlerList handlers = new HandlerList(); 
    ServletContextHandler guiceHandler = new ServletContextHandler(); 

    ServletContextHandler metricsContextHandler = new ServletContextHandler(); 
    metricsContextHandler.setContextPath("/one/metrics"); 
    metricsContextHandler.addEventListener(new MyMetricsServletContextListener(_metricRegistry)); 
    metricsContextHandler.addServlet(MetricsServlet.class, "/registry"); 

    guiceHandler.setContextPath("/one/id"); 
    try { 
     FilterHolder guiceFilter = new FilterHolder(_filter); 
     guiceHandler.addFilter(guiceFilter, "/*", EnumSet.allOf(DispatcherType.class)); 
     handlers.setHandlers(new Handler[]{metricsContextHandler, guiceHandler, resourceHandler}); 
     _server.setHandler(handlers); 
     _server.setDumpAfterStart(true); 
     _server.start(); 
    }catch(Exception ex) { 
     log.error("Error starting http server", ex); 
     throw new RuntimeException(ex); 
    } 

的MetricsServlet.ContextListener實現（經由吉斯結合設置註冊表）：

private static class MyMetricsServletContextListener extends MetricsServlet.ContextListener { 
    private MetricRegistry _metricRegistry; 
    public MyMetricsServletContextListener(MetricRegistry metricRegistry) { 
     _metricRegistry = metricRegistry; 
    } 
    @Override 
    protected MetricRegistry getMetricRegistry() { 
     return _metricRegistry; 
    } 
}