JMX是defacto标准，用于监控与Java虚拟环境有任何关系的所有应用程序。鉴于Groovy直接位于Java之上，Groovy可以利用已经为Java实现的大量工作。
可以使用java.lang.management中提供的标准类来执行JVM的监视。以下代码示例说明如何完成此操作。
| import java.lang.management.* |
| def os = ManagementFactory.operatingSystemMXBean |
| println """OPERATING SYSTEM: |
| OS architecture = $os.arch |
| OS name = $os.name |
| OS version = $os.version |
| OS processors = $os.availableProcessors |
| """ |
| def rt = ManagementFactory.runtimeMXBean |
| println """RUNTIME: |
| Runtime name = $rt.name |
| Runtime spec name = $rt.specName |
| Runtime vendor = $rt.specVendor |
| Runtime spec version = $rt.specVersion |
| Runtime management spec version = $rt.managementSpecVersion |
| """ |
| def mem = ManagementFactory.memoryMXBean |
| def heapUsage = mem.heapMemoryUsage |
| def nonHeapUsage = mem.nonHeapMemoryUsage |
| println """MEMORY: |
| HEAP STORAGE: |
| Memory committed = $heapUsage.committed |
| Memory init = $heapUsage.init |
| Memory max = $heapUsage.max |
| Memory used = $heapUsage.used NON-HEAP STORAGE: |
| Non-heap memory committed = $nonHeapUsage.committed |
| Non-heap memory init = $nonHeapUsage.init |
| Non-heap memory max = $nonHeapUsage.max |
| Non-heap memory used = $nonHeapUsage.used |
| """ |
| println "GARBAGE COLLECTION:" |
| ManagementFactory.garbageCollectorMXBeans.each { gc -> |
| println " name = $gc.name" |
| println " collection count = $gc.collectionCount" |
| println " collection time = $gc.collectionTime" |
| String[] mpoolNames = gc.memoryPoolNames |
| mpoolNames.each { |
| mpoolName -> println " mpool name = $mpoolName" |
| } |
| } |
当代码执行时，输出将根据运行代码的系统而变化。下面给出了输出的样本。
OPERATING SYSTEM:
OS architecture = x86
OS name = Windows 7
OS version = 6.1
OS processors = 4
RUNTIME:
Runtime name = 5144@Babuli-PC
Runtime spec name = Java Virtual Machine Specification
Runtime vendor = Oracle Corporation
Runtime spec version = 1.7
Runtime management spec version = 1.2
MEMORY:
HEAP STORAGE:
Memory committed = 16252928
Memory init = 16777216
Memory max = 259522560
Memory used = 7355840
NON-HEAP STORAGE:
Non-heap memory committed = 37715968
Non-heap memory init = 35815424
Non-heap memory max = 123731968
Non-heap memory used = 18532232
GARBAGE COLLECTION:
name = Copy
collection count = 15
collection time = 47
mpool name = Eden Space
mpool name = Survivor Space
name = MarkSweepCompact
collection count = 0
collection time = 0
mpool name = Eden Space
mpool name = Survivor Space
mpool name = Tenured Gen
mpool name = Perm Gen
mpool name = Perm Gen [shared-ro]
mpool name = Perm Gen [shared-rw]
为了监视tomcat，在启动tomcat时应设置以下参数 -
set JAVA_OPTS = -Dcom.sun.management.jmxremote Dcom.sun.management.jmxremote.port = 9004 -Dcom.sun.management.jmxremote.authenticate=false Dcom.sun.management.jmxremote.ssl = false
以下代码使用JMX发现正在运行的Tomcat中的可用MBean，确定哪些是Web模块并提取每个Web模块的处理时间。
| import groovy.swing.SwingBuilder |
| import javax.management.ObjectName |
| import javax.management.remote.JMXConnectorFactory as JmxFactory |
| import javax.management.remote.JMXServiceURL as JmxUrl |
| import javax.swing.WindowConstants as WC |
| import org.jfree.chart.ChartFactory |
| import org.jfree.data.category.DefaultCategoryDataset as Dataset |
| import org.jfree.chart.plot.PlotOrientation as Orientation |
| def serverUrl = 'service:jmx:rmi:///jndi/rmi://localhost:9004/jmxrmi' |
| def server = JmxFactory.connect(new JmxUrl(serverUrl)).MBeanServerConnection |
| def serverInfo = new GroovyMBean(server, 'Catalina:type = Server').serverInfo |
| println "Connected to: $serverInfo" |
| def query = new ObjectName('Catalina:*') |
| String[] allNames = server.queryNames(query, null) |
| def modules = allNames.findAll { name -> |
| name.contains('j2eeType=WebModule') |
| }.collect{ new GroovyMBean(server, it) } |
| println "Found ${modules.size()} web modules. Processing ..." |
| def dataset = new Dataset() |
| modules.each { m -> |
| println m.name() |
| dataset.addValue m.processingTime, 0, m.path |
| } |
