Netty 应用 | 跟踪诊断 | Console | JMX
    https://blog.csdn.net/weixin_33669968/article/details/104552393

    2. @ChannelHandler.Sharable
    3. public class MetricHandler extends ChannelDuplexHandler {
    5.     private AtomicLong totalConnectionNumber = new AtomicLong();
    7.     {
    8.         MetricRegistry metricRegistry = new MetricRegistry();
    9.         metricRegistry.register("totalConnectionNumber", new Gauge<Long>() {
    10.             public Long getValue() {
    11.                 return totalConnectionNumber.longValue();
    12.             }
    13.         });
    15.         ConsoleReporter consoleReporter = ConsoleReporter.forRegistry(metricRegistry).build();
    16.         consoleReporter.start(5, TimeUnit.SECONDS);
    18.         JmxReporter jmxReporter = JmxReporter.forRegistry(metricRegistry).build();
    19.         jmxReporter.start();
    20.     }
    22.     @Override
    23.     public void channelActive(ChannelHandlerContext ctx) throws Exception {
    24.         totalConnectionNumber.incrementAndGet();
    25.         super.channelActive(ctx);
    26.     }
    28.     @Override
    29.     public void channelInactive(ChannelHandlerContext ctx) throws Exception {
    30.         totalConnectionNumber.decrementAndGet();
    31.         super.channelInactive(ctx);
    32.     }
    34. }