The
ManagementFactory class is a factory class for getting managed beans for the Java platform. This class consists of static methods each of which returns one or more platform MXBeans representing the management interface of a component of the Java virtual machine.
Platform MXBeans
A platform MXBean is a managed bean that conforms to the JMX Instrumentation Specification and only uses a set of basic data types. A JMX management application and the platform MBeanServer can interoperate without requiring classes for MXBean specific data types. The data types being transmitted between the JMX connector server and the connector client are open types and this allows interoperation across versions. See the specification of MXBeans for details.
Each platform MXBean is a PlatformManagedObject and it has a unique ObjectName for registration in the platform MBeanServer as returned by by the getObjectName method.
An application can access a platform MXBean in the following ways:
1. Direct access to an MXBean interface
- Get an MXBean instance by calling the
getPlatformMXBeanorgetPlatformMXBeansmethod and access the MXBean locally in the running virtual machine.- Construct an MXBean proxy instance that forwards the method calls to a given
MBeanServerby calling thegetPlatformMXBean(MBeanServerConnection, Class)orgetPlatformMXBeans(MBeanServerConnection, Class)method. ThenewPlatformMXBeanProxymethod can also be used to construct an MXBean proxy instance of a givenObjectName. A proxy is typically constructed to remotely access an MXBean of another running virtual machine.2. Indirect access to an MXBean interface via MBeanServer
- Go through the platform
MBeanServerto access MXBeans locally or a specific MBeanServerConnection to access MXBeans remotely. The attributes and operations of an MXBean use only JMX open types which include basic data types,CompositeData, andTabularDatadefined inOpenType. The mapping is specified in theMXBean specification for details.
The getPlatformManagementInterfaces method returns all management interfaces supported in the Java virtual machine including the standard management interfaces listed in the tables below as well as the management interfaces extended by the JDK implementation.
A Java virtual machine has a single instance of the following management interfaces:
A Java virtual machine has zero or a single instance of the following management interfaces.
Management Interface ObjectName CompilationMXBeanjava.lang:type=Compilation
A Java virtual machine may have one or more instances of the following management interfaces.
Management Interface ObjectName GarbageCollectorMXBeanjava.lang:type=GarbageCollector,name=collector's nameMemoryManagerMXBeanjava.lang:type=MemoryManager,name=manager's nameMemoryPoolMXBeanjava.lang:type=MemoryPool,name=pool's nameBufferPoolMXBeanjava.nio:type=BufferPool,name=pool name
实例1：
import java.io.IOException;
import java.lang.management.ManagementFactory;
import java.util.Set;
import javax.management.AttributeNotFoundException;
import javax.management.BadAttributeValueExpException;
import javax.management.BadBinaryOpValueExpException;
import javax.management.BadStringOperationException;
import javax.management.InstanceNotFoundException;
import javax.management.IntrospectionException;
import javax.management.InvalidApplicationException;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanException;
import javax.management.MBeanInfo;
import javax.management.MBeanServer;
import javax.management.MBeanServerConnection;
import javax.management.MalformedObjectNameException;
import javax.management.ObjectInstance;
import javax.management.ObjectName;
import javax.management.QueryExp;
import javax.management.ReflectionException;
import javax.management.RuntimeMBeanException; public class JMXUtils { private final static MBeanServer DEFAULT_MBEAN_SERVER = ManagementFactory
.getPlatformMBeanServer(); public static long getYongGC() {
return getYoungGC(DEFAULT_MBEAN_SERVER);
} public static long getFullGC() {
return getFullGC(DEFAULT_MBEAN_SERVER);
} public static long findLoadedClass() {
return findLoadedClass(DEFAULT_MBEAN_SERVER);
} public static long getYoungGC(MBeanServerConnection mbeanServer) {
try {
ObjectName objectName;
if (mbeanServer.isRegistered(new ObjectName("java.lang:type=GarbageCollector,name=ParNew"))) {
objectName = new ObjectName("java.lang:type=GarbageCollector,name=ParNew");
} else if (mbeanServer.isRegistered(new ObjectName("java.lang:type=GarbageCollector,name=Copy"))) {
objectName = new ObjectName("java.lang:type=GarbageCollector,name=Copy");
} else {
objectName = new ObjectName("java.lang:type=GarbageCollector,name=PS Scavenge");
}
return (Long) mbeanServer.getAttribute(objectName , "CollectionCount");
} catch (Exception e) {
throw new RuntimeException(e);
}
} public static long getFullGC(MBeanServerConnection mbeanServer) {
try {
ObjectName objectName;
if (mbeanServer.isRegistered(new ObjectName("java.lang:type=GarbageCollector,name=ConcurrentMarkSweep"))) {
objectName = new ObjectName("java.lang:type=GarbageCollector,name=ConcurrentMarkSweep");
} else if (mbeanServer.isRegistered(new ObjectName("java.lang:type=GarbageCollector,name=MarkSweepCompact"))) {
objectName = new ObjectName("java.lang:type=GarbageCollector,name=MarkSweepCompact");
} else {
objectName = new ObjectName("java.lang:type=GarbageCollector,name=PS MarkSweep");
}
return (Long) mbeanServer.getAttribute(objectName , "CollectionCount");
} catch (Exception e) {
throw new RuntimeException(e);
}
} public static long findLoadedClass(MBeanServerConnection mBeanServer) {
try {
return (Long) (mBeanServer.getAttribute(new ObjectName(
"java.lang:type=ClassLoading"), "TotalLoadedClassCount"));
} catch (Exception e) {
throw new RuntimeException(e);
}
} public static void traceOneDomain(String doMain,
MBeanServerConnection mBeanServer)
throws MalformedObjectNameException, IntrospectionException,
InstanceNotFoundException, AttributeNotFoundException,
ReflectionException, MBeanException, IOException { Set<ObjectInstance> set = mBeanServer.queryMBeans(new ObjectName(doMain + ":*"), new QueryExp() {
private static final long serialVersionUID = 1L; @Override
public boolean apply(ObjectName name)
throws BadStringOperationException,
BadBinaryOpValueExpException,
BadAttributeValueExpException, InvalidApplicationException {
return true;
} @Override
public void setMBeanServer(MBeanServer s) {}
});
for (ObjectInstance objectInstance : set) {
System.out.println("\t\t\t" + objectInstance.getObjectName() + "\t"
+ objectInstance.getClassName());
traceMebeanInfo(mBeanServer, objectInstance.getObjectName());
}
} public static void traceMebeanInfo(MBeanServerConnection mBeanServer,
ObjectName objectName) throws IntrospectionException,
InstanceNotFoundException, MalformedObjectNameException,
ReflectionException, AttributeNotFoundException, MBeanException,
IOException {
MBeanInfo mBeanInfo = mBeanServer.getMBeanInfo(objectName);
MBeanAttributeInfo[] mBeanAttributes = mBeanInfo.getAttributes(); System.out.println("\t\t\tMBeanInfos : ");
for (MBeanAttributeInfo mBeanAttribute : mBeanAttributes) {
try {
System.out.println("\t\t\t\t\t"
+ mBeanAttribute.getName()
+ "\t"
+ mBeanAttribute.getType()
+ "\tvalue = >"
+ mBeanServer.getAttribute(objectName,
mBeanAttribute.getName()));
} catch (RuntimeMBeanException e) {
if (e.getCause() instanceof UnsupportedOperationException) {
System.out.println("\t\t\t\t\t" + mBeanAttribute.getName()
+ "\t" + mBeanAttribute.getType()
+ "\tvalue = > value not supported");
}
} }
} public static void traceAll(MBeanServerConnection mBeanServer)
throws MalformedObjectNameException, IntrospectionException,
InstanceNotFoundException, AttributeNotFoundException,
ReflectionException, MBeanException, IOException {
System.out.println("MBean count = " + mBeanServer.getMBeanCount());
String[] domains = mBeanServer.getDomains();
for (String domain : domains) {
System.out.println("\tbegin trace domain -> " + domain);
traceOneDomain(domain, mBeanServer);
}
}
}
实例2：
<%@ page import="java.lang.management.*" %>
<%@ page import="java.util.*" %>
<html>
<head>
<title>JVM Memory Monitor</title>
</head>
<body>
<table border="0" width="100%">
<tr><td colspan="2" align="center"><h3>Memory MXBean</h3></td></tr>
<tr><td width="200">Heap Memory Usage</td><td><%=ManagementFactory.getMemoryMXBean().getHeapMemoryUsage()%></td></tr>
<tr><td>Non-Heap Memory Usage</td><td><%=ManagementFactory.getMemoryMXBean().getNonHeapMemoryUsage()%></td></tr>
<tr><td colspan="2"> </td></tr>
<tr><td colspan="2" align="center"><h3>Memory Pool MXBeans</h3></td></tr>
<%
Iterator iter = ManagementFactory.getMemoryPoolMXBeans().iterator();
while (iter.hasNext()) {
MemoryPoolMXBean item = (MemoryPoolMXBean) iter.next();
%>
<tr><td colspan="2">
<table border="0" width="100%" style="border: 1px #98AAB1 solid;">
<tr><td colspan="2" align="center"><b><%= item.getName() %></b></td></tr>
<tr><td width="200">Type</td><td><%= item.getType() %></td></tr>
<tr><td>Usage</td><td><%= item.getUsage() %></td></tr>
<tr><td>Peak Usage</td><td><%= item.getPeakUsage() %></td></tr>
<tr><td>Collection Usage</td><td><%= item.getCollectionUsage() %></td></tr>
</table>
</td></tr>
<tr><td colspan="2"> </td></tr>
<%} %>
</table>
</body>
</html>
另外的方式：
内存监控的方法： 1. jmap -heap pid
查看java 堆（heap）使用情况 using thread-local object allocation.
Parallel GC with 4 thread(s) //GC 方式 Heap Configuration: //堆内存初始化配置
MinHeapFreeRatio=40 //对应jvm启动参数-XX:MinHeapFreeRatio设置JVM堆最小空闲比率(default 40)
MaxHeapFreeRatio=70 //对应jvm启动参数 -XX:MaxHeapFreeRatio设置JVM堆最大空闲比率(default 70)
MaxHeapSize=512.0MB //对应jvm启动参数-XX:MaxHeapSize=设置JVM堆的最大大小
NewSize = 1.0MB //对应jvm启动参数-XX:NewSize=设置JVM堆的‘新生代’的默认大小
MaxNewSize =4095MB //对应jvm启动参数-XX:MaxNewSize=设置JVM堆的‘新生代’的最大大小
OldSize = 4.0MB //对应jvm启动参数-XX:OldSize=<value>:设置JVM堆的‘老生代’的大小
NewRatio = 8 //对应jvm启动参数-XX:NewRatio=:‘新生代’和‘老生代’的大小比率
SurvivorRatio = 8 //对应jvm启动参数-XX:SurvivorRatio=设置年轻代中Eden区与Survivor区的大小比值
PermSize= 16.0MB //对应jvm启动参数-XX:PermSize=<value>:设置JVM堆的‘永生代’的初始大小
MaxPermSize=64.0MB //对应jvm启动参数-XX:MaxPermSize=<value>:设置JVM堆的‘永生代’的最大大小 Heap Usage: //堆内存分步
PS Young Generation
Eden Space: //Eden区内存分布
capacity = 20381696 (19.4375MB) //Eden区总容量
used = 20370032 (19.426376342773438MB) //Eden区已使用
free = 11664 (0.0111236572265625MB) //Eden区剩余容量
99.94277218147106% used //Eden区使用比率
From Space: //其中一个Survivor区的内存分布
capacity = 8519680 (8.125MB)
used = 32768 (0.03125MB)
free = 8486912 (8.09375MB)
0.38461538461538464% used
To Space: //另一个Survivor区的内存分布
capacity = 9306112 (8.875MB)
used = 0 (0.0MB)
free = 9306112 (8.875MB)
0.0% used
PS Old Generation //当前的Old区内存分布
capacity = 366280704 (349.3125MB)
used = 322179848 (307.25464630126953MB)
free = 44100856 (42.05785369873047MB)
87.95982001825573% used
PS Perm Generation //当前的 “永生代” 内存分布
capacity = 32243712 (30.75MB)
used = 28918584 (27.57891082763672MB)
free = 3325128 (3.1710891723632812MB)
89.68751488662348% used
参考文献
【1】http://docs.oracle.com/javase/7/docs/api/java/lang/management/ManagementFactory.html
【2】http://blog.csdn.net/xieyuooo/article/details/9817231
【3】http://xstarcd.github.io/wiki/Java/JVM_Heap_Non-heap.html
【4】https://zhidao.baidu.com/question/1989362303218106827.html