Package oshi.util.platform.windows

Class WmiQueryHandler

java.lang.Object

oshi.util.platform.windows.WmiQueryHandler

@ThreadSafe
public class WmiQueryHandler
extends Object

Utility to handle WMI Queries. Designed to be extended with user-customized behavior.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	WmiQueryHandler()

Method Summary

Modifier and Type	Method	Description
static WmiQueryHandler	createInstance()	Factory method to create an instance of this class.
int	getComThreading()	Returns the current threading model for COM initialization, as OSHI is required to match if an external program has COM initialized already.
int	getWmiTimeout()	Gets the current WMI timeout.
protected void	handleComException(com.sun.jna.platform.win32.COM.WbemcliUtil.WmiQuery<?> query, com.sun.jna.platform.win32.COM.COMException ex)	COM Exception handler.
boolean	initCOM()	Initializes COM library and sets security to impersonate the local user
protected boolean	initCOM(int coInitThreading)	Initializes COM with a specific threading model
boolean	isSecurityInitialized()	Security only needs to be initialized once.
<T extends Enum<T>> com.sun.jna.platform.win32.COM.WbemcliUtil.WmiResult<T>	queryWMI(com.sun.jna.platform.win32.COM.WbemcliUtil.WmiQuery<T> query)	Query WMI for values.
<T extends Enum<T>> com.sun.jna.platform.win32.COM.WbemcliUtil.WmiResult<T>	queryWMI(com.sun.jna.platform.win32.COM.WbemcliUtil.WmiQuery<T> query, boolean initCom)	Query WMI for values.
static void	setInstanceClass(Class<? extends WmiQueryHandler> instanceClass)	Define a subclass to be instantiated by createInstance().
void	setWmiTimeout(int wmiTimeout)	Sets the WMI timeout.
int	switchComThreading()	Switches the current threading model for COM initialization, as OSHI is required to match if an external program has COM initialized already.
void	unInitCOM()	UnInitializes COM library.

Methods inherited from class java.lang.Object

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

Constructor Details

WmiQueryHandler

protected WmiQueryHandler()

Method Details

createInstance

public static WmiQueryHandler createInstance()

Factory method to create an instance of this class. To override this class, use setInstanceClass(Class) to define a subclass which extends WmiQueryHandler.

Returns:

An instance of this class or a class defined by setInstanceClass(Class)

setInstanceClass

public static void setInstanceClass(Class<? extends WmiQueryHandler> instanceClass)

Define a subclass to be instantiated by createInstance(). The class must extend WmiQueryHandler.

Parameters:

instanceClass - The class to instantiate with createInstance().

queryWMI

public <T extends Enum<T>>
com.sun.jna.platform.win32.COM.WbemcliUtil.WmiResult<T> queryWMI(com.sun.jna.platform.win32.COM.WbemcliUtil.WmiQuery<T> query)

Query WMI for values. Makes no assumptions on whether the user has previously initialized COM.

Type Parameters:

T - WMI queries use an Enum to identify the fields to query, and use the enum values as keys to retrieve the results.

Parameters:

query - A WmiQuery object encapsulating the namespace, class, and properties

Returns:

a WmiResult object containing the query results, wrapping an EnumMap

queryWMI

public <T extends Enum<T>>
com.sun.jna.platform.win32.COM.WbemcliUtil.WmiResult<T> queryWMI(com.sun.jna.platform.win32.COM.WbemcliUtil.WmiQuery<T> query,
 boolean initCom)

Query WMI for values.

Type Parameters:

T - WMI queries use an Enum to identify the fields to query, and use the enum values as keys to retrieve the results.

Parameters:

query - A WmiQuery object encapsulating the namespace, class, and properties

initCom - Whether to initialize COM. If true, initializes COM before the query and uninitializes after. If false, assumes the user has initialized COM separately. This can improve WMI query performance.

Returns:

a WmiResult object containing the query results, wrapping an EnumMap

handleComException

protected void handleComException(com.sun.jna.platform.win32.COM.WbemcliUtil.WmiQuery<?> query,
 com.sun.jna.platform.win32.COM.COMException ex)

COM Exception handler. Logs a warning message.

Parameters:

query - a WbemcliUtil.WmiQuery object.

ex - a COMException object.

initCOM

public boolean initCOM()

Initializes COM library and sets security to impersonate the local user

Returns:

True if COM was initialized and needs to be uninitialized, false otherwise

initCOM

protected boolean initCOM(int coInitThreading)

Initializes COM with a specific threading model

Parameters:

coInitThreading - The threading model

Returns:

True if COM was initialized and needs to be uninitialized, false otherwise

unInitCOM

public void unInitCOM()

UnInitializes COM library. This should be called once for every successful call to initCOM.

getComThreading

public int getComThreading()

Returns the current threading model for COM initialization, as OSHI is required to match if an external program has COM initialized already.

Returns:

The current threading model

switchComThreading

public int switchComThreading()

Switches the current threading model for COM initialization, as OSHI is required to match if an external program has COM initialized already.

Returns:

The new threading model after switching

isSecurityInitialized

public boolean isSecurityInitialized()

Security only needs to be initialized once. This boolean identifies whether that has happened.

Returns:

Returns the securityInitialized.

getWmiTimeout

public int getWmiTimeout()

Gets the current WMI timeout. WMI queries will fail if they take longer than this number of milliseconds. A value of -1 is infinite (no timeout).

Returns:

Returns the current value of wmiTimeout.

setWmiTimeout

public void setWmiTimeout(int wmiTimeout)

Sets the WMI timeout. WMI queries will fail if they take longer than this number of milliseconds.

Parameters:

wmiTimeout - The wmiTimeout to set, in milliseconds. To disable timeouts, set timeout as -1 (infinite).