获取Full GC的次数

1、Jstat方式

public class Main {
    
    

    private static final String YOUNG_GC_MONITOR_NAME = "sun.gc.collector.0.invocations";
    private static final String FULL_GC_MONITOR_NAME = "sun.gc.collector.1.invocations";

    public static void main(String[] args) throws URISyntaxException, MonitorException {
    
    
        /*
          Returns the managed bean for the runtime system of
          the Java virtual machine.
         */
        String name = ManagementFactory.getRuntimeMXBean().getName();
        //获取pid
        String pid = name.substring(0, name.indexOf("@"));

        VmIdentifier vmId = new VmIdentifier(pid);
        MonitoredHost monitoredHost = MonitoredHost.getMonitoredHost(vmId);
        MonitoredVm monitoredVm = monitoredHost.getMonitoredVm(vmId, 0);

        Monitor youngGCMonitor = monitoredVm.findByName(YOUNG_GC_MONITOR_NAME);
        Monitor fullGCMonitor = monitoredVm.findByName(FULL_GC_MONITOR_NAME);
        System.out.println(youngGCMonitor.getValue());
        System.out.println(fullGCMonitor.getValue());
    }
}

2、收集器名称方式

//新生代GC收集器名称
private Set<String> younggcAlgorithm = new LinkedHashSet<String>() {
    
    
    private static final long serialVersionUID = -2953196532584721351L;

    {
    
    
        this.add("Copy");
        this.add("ParNew");
        this.add("PS Scavenge");
        this.add("G1 Young Generation");
    }
};
//老年代GC收集器名称
private Set<String> oldgcAlgorithm = new LinkedHashSet<String>() {
    
    
    private static final long serialVersionUID = -8267829533109860610L;

    {
    
    
        this.add("MarkSweepCompact");
        this.add("PS MarkSweep");
        this.add("ConcurrentMarkSweep");
        this.add("G1 Old Generation");
    }
};

 //核心代码
 Iterator iterator = ManagementFactory.getGarbageCollectorMXBeans().iterator();
 while(iterator.hasNext()) {
    
    
       GarbageCollectorMXBean garbageCollector = (GarbageCollectorMXBean)iterator.next();
       String gcAlgorithm = garbageCollector.getName();
       if (this.younggcAlgorithm.contains(gcAlgorithm)) {
    
    
           youngGcCount += garbageCollector.getCollectionCount();
       } else if (this.oldgcAlgorithm.contains(gcAlgorithm)) {
    
    
           oldGCount += garbageCollector.getCollectionCount();
       } else {
    
    
           //...
       }
   }

关于GC收集器的名称，可以参考：这里