我如何在不使用类HotSpotDiagnosticMXBean的情况下从应用程序中创建堆转储。
由于java/rt.jar
的访问限制,我无法依赖HotSpotDiagnosticMXBean
对其进行编译。我知道如何解决eclipse.compiler错误,但是如何为我的版本修复它?
除了以编程方式创建堆转储以外,还有其他方法吗?
最佳答案
好的,似乎您可以使用反射来绕过限制:
package lab.heapdump;
import javax.management.MBeanServer;
import java.lang.management.ManagementFactory;
import java.lang.reflect.Method;
@SuppressWarnings("restriction")
public class HeapDump {
// 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 Object 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 {
Class clazz = Class.forName("com.sun.management.HotSpotDiagnosticMXBean");
Method m = clazz.getMethod("dumpHeap", String.class, boolean.class);
m.invoke( hotspotMBean , 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 (HeapDump.class) {
if (hotspotMBean == null) {
hotspotMBean = getHotspotMBean();
}
}
}
}
// get the hotspot diagnostic MBean from the
// platform MBean server
private static Object getHotspotMBean() {
try {
Class clazz = Class.forName("com.sun.management.HotSpotDiagnosticMXBean");
MBeanServer server = ManagementFactory.getPlatformMBeanServer();
Object bean =
ManagementFactory.newPlatformMXBeanProxy(server,
HOTSPOT_BEAN_NAME, clazz);
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 = "D:\\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);
}
}