使用拖放向导指标获取 JMX 值-Jvm

Question

我尝试使用dropWizard库获取JVM度量值（MemoryUsageGaugeSet、GarbageCollectionUsageGaigeSet）

 <dependency>
    <groupId>io.dropwizard.metrics</groupId>
    <artifactId>metrics-jvm</artifactId>
    <version>3.1.2</version>
 </dependency>

代码实现。

  public static void main(String[] args ){
  MemoryUsageGaugeSet memory = new MemoryUsageGaugeSet();
  Map<String, Metric> memoryMap = memory.getMetrics();
  system.out.println( memoryMap);}

我得到的结果是

{heap.committed=com.codahale.metrics.jvm.MemoryUsageGaugeSet$8@d16011， non-heap.used=com.codahale.metrics.jvm.MemoryUsageGaugeSet$11@cc09904， pools.Code-Cache.used=com.codahale.metrics.jvm.MemoryUsageGaugeSet$17@748032cc， pools.Code-Cache.committed=com.codahale.metrics.jvm.MemoryUsageGaugeSet$18@2b6e0423， heap.used=com.codahale.metrics.jvm.MemoryUsageGaugeSet$6@203428b7， pools.PS-Old-Gen.init=com.codahale.metrics.jvm.MemoryUsageGaugeSet$19@28b49d0c， total.committed=com.codahale.metrics.jvm.MemoryUsageGaugeSet$4@5dd7cc84， pools.PS-Old-Gen.max=com.codahale.metrics.jvm.MemoryUsageGaugeSet$16@6438401， total.init=com.codahale.metrics.jvm.MemoryUsageGaugeSet$1@7b365ee， non-heap.max=com.codahale.metrics.jvm.MemoryUsageGaugeSet$12@be3d4e9， pools.PS-Eden-Space.init=com.codahale.metrics.jvm.MemoryUsageGaugeSet$19@68339afd， pools.压缩类空间.used=com.codahale.metrics.jvm.MemoryUsageGaugeSet$17@724a6876， pools.Metaspace.usage=com.codahale.metrics.jvm.MemoryUsageGaugeSet$15@6ecaffc4， pools.Metaspace.max=com.codahale.metrics.jvm.MemoryUsageGaugeSet$16@7b1b3a68， pools.PS-Eden-Space.committed=com.codahale.metrics.jvm.MemoryUsageGaugeSet$18@f8ba384， pools.PS-Eden-Space.max=com.codahale.metrics.jvm.MemoryUsageGaugeSet$16@2e2373db， pools.压缩类空间.usage=com.codahale.metrics.jvm.MemoryUsageGaugeSet$15@17ae8d04， 堆.usage=com.codahale.metrics.jvm.MemoryUsageGaugeSet$9@35c43de3， pools.PS-Eden-Space.usage=com.codahale.metrics.jvm.MemoryUsageGaugeSet$15@67013f5c， pools.PS-Survivor-Space.max=com.codahale.metrics.jvm.MemoryUsageGaugeSet$16@520935cc， pools.Code-Cache.max=com.codahale.metrics.jvm.MemoryUsageGaugeSet$16@31ac5424， pools.Compress-Class-Space.init=com.codahale.metrics.jvm.MemoryUsageGaugeSet$19@25135cd7， pools.Metaspace.init=com.codahale.metrics.jvm.MemoryUsageGaugeSet$19@4b066cf6， pools.PS-Surviver-Space.usage=com.codahale.metrics.jvm.MemoryUsageGaugeSet$15@50ba970f， pools.PS-Old-Gen.usage=com.codahale.metrics.jvm.MemoryUsageGaugeSet$15@3e4e448， pools.Code-Cache.usage=com.codahale.metrics.jvm.MemoryUsageGaugeSet$15@3c2ef507， pools.PS-Survivor-Space.init=com.codahale.metrics.jvm.MemoryUsageGaugeSet$19@44374fa8， total.used=com.codahale.metrics.jvm.MemoryUsageGaugeSet$2@40b1aace， pools.Code-Cache.init=com.codahale.metrics.jvm.MemoryUsageGaugeSet$19@6453d034， pools.PS-Old-Gen.committed=com.codahale.metrics.jvm.MemoryUsageGaugeSet$18@2f9e8774， 堆.init=com.codahale.metrics.jvm.MemoryUsageGaugeSet$5@512ad720， non-heap.committed=com.codahale.metrics.jvm.MemoryUsageGaugeSet$13@1c80e011， pools.Compressed-Class-Space.committed=com.codahale.metrics.jvm.MemoryUsageGaugeSet$18@662841c5， non-heap.init=com.codahale.metrics.jvm.MemoryUsageGaugeSet$10@3dd6cf53， pools.PS-Eden-Space.used=com.codahale.metrics.jvm.MemoryUsageGaugeSet$17@3a428c1e， non-heap.usage=com.codahale.metrics.jvm.MemoryUsageGaugeSet$14@21d9632f， 堆.max=com.codahale.metrics.jvm.MemoryUsageGaugeSet$7@5db28b8， pools.PS-Surviver-Space.used=com.codahale.metrics.jvm.MemoryUsageGaugeSet$17@efcd307， pools.Metaspace.committed=com.codahale.metrics.jvm.MemoryUsageGaugeSet$18@20f09cba， total.max=com.codahale.metrics.jvm.MemoryUsageGaugeSet$3@4ada5390， pools.Metaspace.used=com.codahale.metrics.jvm.MemoryUsageGaugeSet$17@16982c9b， pools.压缩类空间.max=com.codahale.metrics.jvm.MemoryUsageGaugeSet$16@7e94b1a4， pools.PS-Surviver-Space.committed=com.codahale.metrics.jvm.MemoryUsageGaugeSet$18@5aa5f780， pools.PS-Old-Gen.used=com.codahale.metrics.jvm.MemoryUsageGaugeSet$17@427b7997}

我得到了对象的引用，而不是这些引用的值。怎么办？

Answer 1

要获取/打印对象的值，需要在类中实现＜code＞toString（）没有。验证@javadoc

一种方法是使用自己的实现toString（）扩展类。

另一种方法是遍历地图并打印每个值。您可能想尝试下面这样的东西.

Map<String, Metric> memoryMap = memory.getMetrics();

for (String key : memoryMap.keySet()) {
    Metric m = memoryMap.get(key);
    System.out.println(m.getClass());

    if (m instanceof Gauge) {
        System.out.println(((Gauge<Long>) m).getValue());
    }
}

memorySageGaugeSet产生仪表

希望这能有所帮助。