MemoryPoolMXBean

MemoryPoolMXBean

java.lang.management

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Java 5.0

This MXBean interface allows monitoring of the current and peak memory usage for a single memory pool. Typical Java VM implementations segregate garbage-collected heap memory into two or more memory pools based on the age of the objects. Obtain a List of MemoryPoolMXBean instances with ManagementFactory.getMemoryPoolMXBeans( ) . getName( ) and getType( ) return the name and type of each pool. getUsage( ) and getPeakUsage( ) return the current and peak memory usage for the pool in the form of a MemoryUsage object.

If isUsageThresholdSupported( ) returns TRue , you can use setUsageThreshold( ) to define a memory usage threshold. The MemoryPoolMXBean then keeps track of threshold crossings and issues notifications through the javax.management.NotificationEmitter API. You can register a javax.management.NotificationListener to receive these notifications. (Note that the javax.management package is not covered in this book.) Use setCollectionUsageThreshold( ) instead to receive notifications when memory usage exceeds a specified threshold after a garbage collection pass.

 public interface  MemoryPoolMXBean  {  // Public Instance Methods  MemoryUsage  getCollectionUsage  ( );        long  getCollectionUsageThreshold  ( );        long  getCollectionUsageThresholdCount  ( );        String[ ]  getMemoryManagerNames  ( );        String  getName  ( );        MemoryUsage  getPeakUsage  ( );        MemoryType  getType  ( );        MemoryUsage  getUsage  ( );        long  getUsageThreshold  ( );        long  getUsageThresholdCount  ( );        boolean  isCollectionUsageThresholdExceeded  ( );        boolean  isCollectionUsageThresholdSupported  ( );        boolean  isUsageThresholdExceeded  ( );        boolean  isUsageThresholdSupported  ( );        boolean  isValid  ( );        void  resetPeakUsage  ( );        void  setCollectionUsageThreshold  (long  threhsold  );        void  setUsageThreshold  (long  threshold  );   }