com.iizix.os

Class OSSystemInfo<INFO>

java.lang.Object

com.iizix.os.OSSystemInfo<INFO>

public class OSSystemInfo<INFO>
extends Object

Package to retrieve system information from the OS.

Author:

Christopher Mindus

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	OSSystemInfo.Basic Basic OS and JVM information class.
static class	OSSystemInfo.Details Detailed information class.
static class	OSSystemInfo.HistoryEntry<INFO> The history entry information.

Field Summary

Fields

Modifier and Type	Field and Description
static long	DEFAULT_INTERVAL The default history gatherer interval: 30 seconds.

Constructor Summary

Constructors

Constructor and Description
OSSystemInfo(IAdditonalInformation<INFO> informationProvider) The constructor.

Method Summary

Modifier and Type	Method and Description
static int	getAvailableProcessors() Gets the number of processors available to the Java virtual machine.
static OSSystemInfo.Basic	getBasic() Gets the basic information.
static OSSystemInfo.Details	getDetails() Gets detailed information of the OS and process memory/swap space usage and CPU load.
OSSystemInfo.HistoryEntry<INFO>[]	getHistory(long start) Gets the history entries gathered between a date up to the last available entry.
long	getHistoryInterval() Gets the interval used for gathering of history entries.
static double	getSystemLoadAverage() Gets the average load during the last minute.
boolean	isGatheringHistory() Checks if history is being gathered.
void	setMaxHistorySize(int maxSize) Sets the maximum number of entries in the history.
boolean	startHistory(long interval) Starts the history gatherer.
boolean	stopHistory() Stops the history gatherer.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_INTERVAL

public static final long DEFAULT_INTERVAL

The default history gatherer interval: 30 seconds.

See Also:

Constant Field Values

Constructor Detail

OSSystemInfo

public OSSystemInfo(IAdditonalInformation<INFO> informationProvider)

The constructor.

Parameters:

informationProvider - The additional information provider to be stored with the history data, or null for none.

Method Detail

getBasic

public static OSSystemInfo.Basic getBasic()

Gets the basic information.

If a security manager prohibits access to the OS information, a warning message is logged in the console.

Returns:

The basic information, or null if the OS management bean failed loading or a security manager restricts access to the OS information.

getSystemLoadAverage

public static double getSystemLoadAverage()

Gets the average load during the last minute.

Returns:

The load between 0.0 to 1.0, negative if not available.

getAvailableProcessors

public static int getAvailableProcessors()

Gets the number of processors available to the Java virtual machine. Note that this value may change during the JVM lifetime.

Returns:

The number of processors, never smaller than 1.

getDetails

public static OSSystemInfo.Details getDetails()

Gets detailed information of the OS and process memory/swap space usage and CPU load.

Returns:

The details instance or null if not supported.

startHistory

public boolean startHistory(long interval)

Starts the history gatherer. This clears the history. If the gathering information is not available, a warning message is logged, otherwise an information message is logged about the start.

Parameters:

interval - In milliseconds.

Returns:

true for OK, false if already started or history not available due to security restrictions.

setMaxHistorySize

public void setMaxHistorySize(int maxSize)

Sets the maximum number of entries in the history.

Parameters:

maxSize - The maximum size, between 100 and 100_000.

Throws:

IllegalArgumentException - If range is invalid.

getHistoryInterval

public long getHistoryInterval()

Gets the interval used for gathering of history entries.

Returns:

Interval in milliseconds, zero if never started.

isGatheringHistory

public boolean isGatheringHistory()

Checks if history is being gathered.

Returns:

true if timer is running, false otherwise.

stopHistory

public boolean stopHistory()

Stops the history gatherer.

Returns:

true for OK, false if already stopped or never started.

getHistory

public OSSystemInfo.HistoryEntry<INFO>[] getHistory(long start)

Gets the history entries gathered between a date up to the last available entry. The history entries are gathered at specific interval defined at start of history.

Parameters:

start - The start time for the events in milliseconds since the Epoch, or zero for all history entries.

Returns:

The entries, possibly empty array.