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。
监视JVM
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]
监控Tomcat
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