JMX：Java Management Extensions ，可以管理，监控运行中的Java程序。
Groovy结合JMX可以实现很多工作：

监视JVM

通过java.lang.management提供的标准类可以对JVM进行监视：

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"
   } 
}

代码执行的时候回根据运行时的系统而变化：

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

为了监控Tomcat，在启动Tomcat的时候设置以下参数：

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