投稿と議論をしてくれた Nicholas と Scott に感謝します。その情報といくつかの試行錯誤に基づいて、これをつなぎ合わせることができました。
共有することで、他の人が同じ作業を行う必要がなくなります。これは JVM にアタッチし、そのメモリ使用量を取得します。
import com.sun.tools.attach.VirtualMachine;
import com.sun.tools.attach.VirtualMachineDescriptor;
import com.sun.tools.attach.spi.AttachProvider;
import javax.management.MBeanServerConnection;
import javax.management.ObjectName;
import javax.management.openmbean.CompositeData;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;
public class AttachFun {
public static void main(String[] args) throws Exception {
final AttachProvider attachProvider = AttachProvider.providers().get(0);
VirtualMachineDescriptor descriptor = null;
for (VirtualMachineDescriptor virtualMachineDescriptor : attachProvider.listVirtualMachines()) {
if (pickThisOne(virtualMachineDescriptor)) {
descriptor = virtualMachineDescriptor;
break;
}
}
if (descriptor == null) throw new RuntimeException("You didn't pick one");
final VirtualMachine virtualMachine = attachProvider.attachVirtualMachine(descriptor);
virtualMachine.loadAgent("/System/Library/Frameworks/JavaVM.framework/Home/lib/management-agent.jar", "com.sun.management.jmxremote");
final Object portObject = virtualMachine.getAgentProperties().get("com.sun.management.jmxremote.localConnectorAddress");
final JMXServiceURL target = new JMXServiceURL(portObject + "");
final JMXConnector connector = JMXConnectorFactory.connect(target);
final MBeanServerConnection remote = connector.getMBeanServerConnection();
final ObjectName memory = new ObjectName("java.lang:type=Memory");
CompositeData cd = (CompositeData) remote.getAttribute(memory, "HeapMemoryUsage");
final Long used = (Long) cd.get("used");
System.out.println(used);
}
private static boolean pickThisOne(VirtualMachineDescriptor virtualMachineDescriptor) {
// TODO
return false;
}
}