OpenJDK 27 · java.lang.management.BufferPoolMXBean · APIdia, the JavaDoc alternative

The management interface for a buffer pool, for example a pool of direct or mapped buffers.

A class implementing this interface is an javax.management.MXBean. A Java virtual machine has one or more implementations of this interface. The getPlatformMXBeans method can be used to obtain the list of BufferPoolMXBean objects representing the management interfaces for pools of buffers as follows:

    List<BufferPoolMXBean> pools = ManagementFactory.getPlatformMXBeans(BufferPoolMXBean.class);

The management interfaces are also registered with the platform MBeanServer. The ObjectName that uniquely identifies the management interface within the MBeanServer takes the form:

    java.nio:type=BufferPool,name=pool name

where pool name is the name of the buffer pool.

Method Summary

Modifier and Type	Method and Description
public long	Returns: An estimate of the number of buffers in this pool getCount() Returns an estimate of the number of buffers in the pool.
public long	Returns: An estimate of the memory that the Java virtual machine is using for this buffer pool in bytes, or `-1L` if an estimate of the memory usage is not available getMemoryUsed() Returns an estimate of the memory that the Java virtual machine is using for this buffer pool.
public String	Returns: The name of this buffer pool. getName() Returns the name representing this buffer pool.
public long	Returns: An estimate of the total capacity of the buffers in this pool in bytes getTotalCapacity() Returns an estimate of the total capacity of the buffers in this pool.

Inherited from java.lang.management.PlatformManagedObject:: getObjectName

Method Detail

getCount	back to summary
public long getCount() Returns an estimate of the number of buffers in the pool. Returns:long An estimate of the number of buffers in this pool

getCount

back to summary

public long getCount()

Returns an estimate of the number of buffers in the pool.

Returns:long: An estimate of the number of buffers in this pool

getMemoryUsed back to summary

getMemoryUsed	back to summary
public long getMemoryUsed() Returns an estimate of the memory that the Java virtual machine is using for this buffer pool. The value returned by this method may differ from the estimate of the total `capacity` of the buffers in this pool. This difference is explained by alignment, memory allocator, and other implementation specific reasons. Returns:long An estimate of the memory that the Java virtual machine is using for this buffer pool in bytes, or `-1L` if an estimate of the memory usage is not available

public long getMemoryUsed()

Returns an estimate of the memory that the Java virtual machine is using for this buffer pool. The value returned by this method may differ from the estimate of the total capacity of the buffers in this pool. This difference is explained by alignment, memory allocator, and other implementation specific reasons.

Returns:long: An estimate of the memory that the Java virtual machine is using for this buffer pool in bytes, or -1L if an estimate of the memory usage is not available

getName	back to summary
public String getName() Returns the name representing this buffer pool. Returns:String The name of this buffer pool.

getName

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public String getName()

Returns the name representing this buffer pool.

Returns:String: The name of this buffer pool.

getTotalCapacity	back to summary
public long getTotalCapacity() Returns an estimate of the total capacity of the buffers in this pool. A buffer's capacity is the number of elements it contains and the value returned by this method is an estimate of the total capacity of buffers in the pool in bytes. Returns:long An estimate of the total capacity of the buffers in this pool in bytes

getTotalCapacity

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public long getTotalCapacity()

Returns an estimate of the total capacity of the buffers in this pool. A buffer's capacity is the number of elements it contains and the value returned by this method is an estimate of the total capacity of buffers in the pool in bytes.

Returns:long: An estimate of the total capacity of the buffers in this pool in bytes

public Interface BufferPoolMXBean

Method Summary

Method Detail