Java HeapDump 生成解析

jmap -dump：格式= b，文件= <文件路径> <pid>
pid：Java进程ID，应捕获其堆转储
file-path：堆转储将写入的文件路径。

[administrator@JavaLangOutOfMemory ~ ] % jmap -dump:live,format=b,file=/data/logs/heap.hprof <pid>

-XX:+HeapDumpOnOutOfMemoryError -XX:+HeapDumpBeforeFullGC -XX:+HeapDumpAfterFullGC -XX:HeapDumpPath=

jcmd <pid> GC.heap_dump <file-path>
where
pid: is the Java Process Id, whose heap dump should be captured
file-path: is the file path where heap dump will be written in to.

[administrator@JavaLangOutOfMemory ~ ] % jcmd <pid> GC.heap_dump /data/logs/heapdump.bin

import javax.management.MBeanServer;
import java.lang.management.ManagementFactory;
import com.sun.management.HotSpotDiagnosticMXBean;
public class HeapDumper {
    // This is the name of the HotSpot Diagnostic MBean
    private static final String HOTSPOT_BEAN_NAME =
         "com.sun.management:type=HotSpotDiagnostic";
    // field to store the hotspot diagnostic MBean 
    private static volatile HotSpotDiagnosticMXBean hotspotMBean;
    /\*\*
     \* Call this method from your application whenever you 
     \* want to dump the heap snapshot into a file.
     \*
     \* @param fileName name of the heap dump file
     \* @param live flag that tells whether to dump
     \*             only the live objects
     \*/
    static void dumpHeap(String fileName, boolean live) {
        // initialize hotspot diagnostic MBean
        initHotspotMBean();
        try {
            hotspotMBean.dumpHeap(fileName, live);
        } catch (RuntimeException re) {
            throw re;
        } catch (Exception exp) {
            throw new RuntimeException(exp);
        }
    }
    // initialize the hotspot diagnostic MBean field
    private static void initHotspotMBean() {
        if (hotspotMBean == null) {
            synchronized (HeapDumper.class) {
                if (hotspotMBean == null) {
                    hotspotMBean = getHotspotMBean();
                }
            }
        }
    }
    // get the hotspot diagnostic MBean from the
    // platform MBean server
    private static HotSpotDiagnosticMXBean getHotspotMBean() {
        try {
            MBeanServer server = ManagementFactory.getPlatformMBeanServer();
            HotSpotDiagnosticMXBean bean = 
                ManagementFactory.newPlatformMXBeanProxy(server,
                HOTSPOT_BEAN_NAME, HotSpotDiagnosticMXBean.class);
            return bean;
        } catch (RuntimeException re) {
            throw re;
        } catch (Exception exp) {
            throw new RuntimeException(exp);
        }
    }
    public static void main(String[] args) {
        // default heap dump file name
        String fileName = "heap.bin";
        // by default dump only the live objects
        boolean live = true;
        // simple command line options
        switch (args.length) {
            case 2:
                live = args[1].equals("true");
            case 1:
                fileName = args[0];
        }
        // dump the heap
        dumpHeap(fileName, live);
    }
}