在JDK1.7中，您可以通过com.sun.management.OperatingSystemMXBean..这与java.lang.management.OperatingSystemMXBean.
long getCommittedVirtualMemorySize()
Returns the amount of virtual memory that is guaranteed to be available to the running process in bytes, or -1 if this operation is not supported.
long getFreePhysicalMemorySize()
Returns the amount of free physical memory in bytes.
long getFreeSwapSpaceSize()
Returns the amount of free swap space in bytes.
double getProcessCpuLoad()
Returns the "recent cpu usage" for the Java Virtual Machine process.
long getProcessCpuTime()
Returns the CPU time used by the process on which the Java virtual machine is running in nanoseconds.
double getSystemCpuLoad()
Returns the "recent cpu usage" for the whole system.
long getTotalPhysicalMemorySize()
Returns the total amount of physical memory in bytes.
long getTotalSwapSpaceSize()
Returns the total amount of swap space in bytes.
