Package com.sun.jna

Klasse Function

java.lang.Object

com.sun.jna.Pointer

com.sun.jna.Function

public class Function
extends Pointer

An abstraction for a native function pointer. An instance of Function represents a pointer to some native function. invoke(Class,Object[],Map) is the primary means to call the function.

Function call behavior may be modified by passing one of the following call flags:

• C_CONVENTION Use C calling convention (default)
• ALT_CONVENTION Use alternate calling convention (e.g. stdcall)
• THROW_LAST_ERROR Throw a LastErrorException if the native function sets the system error to a non-zero value (errno or GetLastError). Setting this flag will cause the system error to be cleared prior to native function invocation.

Autor:

Sheng Liang, originator, Todd Fast, suitability modifications, Timothy Wall

Siehe auch:

• Pointer

Verschachtelte Klassen - Übersicht

Verschachtelte Klassen

Modifizierer und Typ	Klasse	Beschreibung
static interface	Function.PostCallRead	Any argument which implements this interface will have the Function.PostCallRead.read() method called immediately after function invocation.

Feldübersicht

Felder

Modifizierer und Typ	Feld	Beschreibung
static final int	ALT_CONVENTION	First alternate convention (currently used only for w32 stdcall).
static final int	C_CONVENTION	Standard C calling convention.
(Package privat) final int	callFlags
(Package privat) final String	encoding
(Package privat) static final Integer	INTEGER_FALSE
(Package privat) static final Integer	INTEGER_TRUE
static final int	MAX_NARGS	Maximum number of arguments supported by a JNA function call.
(Package privat) static final String	OPTION_INVOKING_METHOD	For internal JNA use.
(Package privat) final Map<String,?>	options
static final int	THROW_LAST_ERROR	Whether to throw an exception if last error is non-zero after call.
static final int	USE_VARARGS	Mask for number of fixed args (max 255) for varargs calls.

Von Klasse geerbte Felder com.sun.jna.Pointer

NULL, peer

Konstruktorübersicht

Konstruktoren

Konstruktor	Beschreibung
Function(NativeLibrary library, String functionName, int callFlags, String encoding)	Create a new Function that is linked with a native function that follows the given calling convention.
Function(Pointer functionAddress, int callFlags, String encoding)	Create a new Function that is linked with a native function that follows the given calling convention.

Methodenübersicht

Modifizierer und Typ	Methode	Beschreibung
(Package privat) static Object[]	concatenateVarArgs(Object[] inArgs)	Concatenate varargs with normal args to obtain a simple argument array.
boolean	equals(Object o)	Two function pointers are equal if they share the same peer address and calling convention.
(Package privat) static int	fixedArgs(Method m)	Varargs are only supported on 1.5+.
int	getCallingConvention()
static Function	getFunction(Pointer p)	Obtain a Function representing a native function pointer.
static Function	getFunction(Pointer p, int callFlags)	Obtain a Function representing a native function pointer.
static Function	getFunction(Pointer p, int callFlags, String encoding)	Obtain a Function representing a native function pointer.
static Function	getFunction(String libraryName, String functionName)	Obtain a Function representing a native function that follows the standard "C" calling convention.
static Function	getFunction(String libraryName, String functionName, int callFlags)	Obtain a Function representing a native function.
static Function	getFunction(String libraryName, String functionName, int callFlags, String encoding)	Obtain a Function representing a native function.
String	getName()
int	hashCode()	Provide a unique hash code for Functions which are equivalent.
Object	invoke(Class<?> returnType, Object[] inArgs)	Invoke the native function with the given arguments, returning the native result as an Object.
Object	invoke(Class<?> returnType, Object[] inArgs, Map<String,?> options)	Invoke the native function with the given arguments, returning the native result as an Object.
void	invoke(Object[] args)	Call the native function being represented by this object
(Package privat) Object	invoke(Object[] args, Class<?> returnType, boolean allowObjects)
(Package privat) Object	invoke(Object[] args, Class<?> returnType, boolean allowObjects, int fixedArgs)
(Package privat) Object	invoke(Method invokingMethod, Class<?>[] paramTypes, Class<?> returnType, Object[] inArgs, Map<String,?> options)	Invoke the native function with the given arguments, returning the native result as an Object.
double	invokeDouble(Object[] args)	Convenience method for invoke(Double.class, args).
float	invokeFloat(Object[] args)	Convenience method for invoke(Float.class, args).
int	invokeInt(Object[] args)	Convenience method for invoke(Integer.class, args).
long	invokeLong(Object[] args)	Convenience method for invoke(Long.class, args).
Object	invokeObject(Object[] args)	Convenience method for invokeObject(Object.class, args).
Pointer	invokePointer(Object[] args)	Convenience method for invoke(Pointer.class, args).
String	invokeString(Object[] args, boolean wide)	Convenience method for invoke(String.class, args) or invoke(WString.class, args)
void	invokeVoid(Object[] args)	Convenience method for invoke(Void.class, args).
(Package privat) static boolean	isVarArgs(Method m)	Varargs are only supported on 1.5+.
String	toString()	Provide a human-readable representation of this object.
(Package privat) static Boolean	valueOf(boolean b)	Implementation of Boolean.valueOf for older VMs.

Von Klasse geerbte Methoden com.sun.jna.Pointer

clear, createConstant, createConstant, dump, getByte, getByteArray, getByteBuffer, getChar, getCharArray, getDouble, getDoubleArray, getFloat, getFloatArray, getInt, getIntArray, getLong, getLongArray, getNativeLong, getPointer, getPointerArray, getPointerArray, getShort, getShortArray, getString, getString, getStringArray, getStringArray, getStringArray, getStringArray, getValue, getWideString, getWideStringArray, getWideStringArray, indexOf, nativeValue, nativeValue, read, read, read, read, read, read, read, read, setByte, setChar, setDouble, setFloat, setInt, setLong, setMemory, setNativeLong, setPointer, setShort, setString, setString, setString, setValue, setWideString, share, share, write, write, write, write, write, write, write, write

Von Klasse geerbte Methoden java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Felddetails

MAX_NARGS

@Native
public static final int MAX_NARGS

Maximum number of arguments supported by a JNA function call.

Siehe auch:

• Konstantenfeldwerte

C_CONVENTION

@Native
public static final int C_CONVENTION

Standard C calling convention.

Siehe auch:

• Konstantenfeldwerte

ALT_CONVENTION

@Native
public static final int ALT_CONVENTION

First alternate convention (currently used only for w32 stdcall).

Siehe auch:

• Konstantenfeldwerte

THROW_LAST_ERROR

@Native
public static final int THROW_LAST_ERROR

Whether to throw an exception if last error is non-zero after call.

Siehe auch:

• Konstantenfeldwerte

USE_VARARGS

@Native
public static final int USE_VARARGS

Mask for number of fixed args (max 255) for varargs calls.

Siehe auch:

• Konstantenfeldwerte

INTEGER_TRUE

static final Integer INTEGER_TRUE

INTEGER_FALSE

static final Integer INTEGER_FALSE

encoding

final String encoding

callFlags

final int callFlags

options

final Map<String,?> options

OPTION_INVOKING_METHOD

static final String OPTION_INVOKING_METHOD

For internal JNA use.

Siehe auch:

• Konstantenfeldwerte

Konstruktordetails

Function

Function(NativeLibrary library,
 String functionName,
 int callFlags,
 String encoding)

Create a new Function that is linked with a native function that follows the given calling convention.

The allocated instance represents a pointer to the named native function from the supplied library, called with the given calling convention.

Parameter:

library - NativeLibrary in which to find the function

functionName - Name of the native function to be linked with

callFlags - Function call flags

encoding - Encoding for conversion between Java and native strings.

Löst aus:

UnsatisfiedLinkError - if the given function name is not found within the library.

Function

Function(Pointer functionAddress,
 int callFlags,
 String encoding)

Create a new Function that is linked with a native function that follows the given calling convention.

The allocated instance represents a pointer to the given function address, called with the given calling convention.

Parameter:

functionAddress - Address of the native function

callFlags - Function call flags

encoding - Encoding for conversion between Java and native strings.

Methodendetails

getFunction

public static Function getFunction(String libraryName,
 String functionName)

Obtain a Function representing a native function that follows the standard "C" calling convention.

The allocated instance represents a pointer to the named native function from the named library, called with the standard "C" calling convention.

Parameter:

libraryName - Library in which to find the native function

functionName - Name of the native function to be linked with

Löst aus:

UnsatisfiedLinkError - if the library is not found or the given function name is not found within the library.

getFunction

public static Function getFunction(String libraryName,
 String functionName,
 int callFlags)

Obtain a Function representing a native function.

The allocated instance represents a pointer to the named native function from the named library.

Parameter:

libraryName - Library in which to find the function

functionName - Name of the native function to be linked with

callFlags - Function call flags

Löst aus:

UnsatisfiedLinkError - if the library is not found or the given function name is not found within the library.

getFunction

public static Function getFunction(String libraryName,
 String functionName,
 int callFlags,
 String encoding)

Obtain a Function representing a native function.

The allocated instance represents a pointer to the named native function from the named library.

Parameter:

libraryName - Library in which to find the function

functionName - Name of the native function to be linked with

callFlags - Function call flags

encoding - Encoding to use for conversion between Java and native strings.

Löst aus:

UnsatisfiedLinkError - if the library is not found or the given function name is not found within the library.

getFunction

public static Function getFunction(Pointer p)

Obtain a Function representing a native function pointer. In general, this function should be used by dynamic languages; Java code should allow JNA to bind to a specific Callback interface instead by defining a return type or Structure field type.

The allocated instance represents a pointer to the native function pointer.

Parameter:

p - Native function pointer

getFunction

public static Function getFunction(Pointer p,
 int callFlags)

Obtain a Function representing a native function pointer. In general, this function should be used by dynamic languages; Java code should allow JNA to bind to a specific Callback interface instead by defining a return type or Structure field type.

The allocated instance represents a pointer to the native function pointer.

Parameter:

p - Native function pointer

callFlags - Function call flags

getFunction

public static Function getFunction(Pointer p,
 int callFlags,
 String encoding)

Obtain a Function representing a native function pointer. In general, this function should be used by dynamic languages; Java code should allow JNA to bind to a specific Callback interface instead by defining a return type or Structure field type.

The allocated instance represents a pointer to the native function pointer.

Parameter:

p - Native function pointer

callFlags - Function call flags

encoding - Encoding to use for conversion between Java and native strings.

getName

public String getName()

getCallingConvention

public int getCallingConvention()

invoke

public Object invoke(Class<?> returnType,
 Object[] inArgs)

Invoke the native function with the given arguments, returning the native result as an Object.

invoke

public Object invoke(Class<?> returnType,
 Object[] inArgs,
 Map<String,?> options)

Invoke the native function with the given arguments, returning the native result as an Object.

invoke

Object invoke(Method invokingMethod,
 Class<?>[] paramTypes,
 Class<?> returnType,
 Object[] inArgs,
 Map<String,?> options)

Invoke the native function with the given arguments, returning the native result as an Object. This method can be called if invoking method and parameter types are already at hand. When calling invoke(Class, Object[], Map), the method has to be in the options under key OPTION_INVOKING_METHOD.

invoke

Object invoke(Object[] args,
 Class<?> returnType,
 boolean allowObjects)

invoke

Object invoke(Object[] args,
 Class<?> returnType,
 boolean allowObjects,
 int fixedArgs)

invoke

public void invoke(Object[] args)

Call the native function being represented by this object

Parameter:

args - Arguments to pass to the native function

toString

public String toString()

Provide a human-readable representation of this object.

Setzt außer Kraft:

toString in Klasse Pointer

invokeObject

public Object invokeObject(Object[] args)

Convenience method for invokeObject(Object.class, args).

invokePointer

public Pointer invokePointer(Object[] args)

Convenience method for invoke(Pointer.class, args).

invokeString

public String invokeString(Object[] args,
 boolean wide)

Convenience method for invoke(String.class, args) or invoke(WString.class, args)

Parameter:

args - Arguments passed to native function

wide - Whether the return value is of type wchar_t*; if false, the return value is of type char*.

invokeInt

public int invokeInt(Object[] args)

Convenience method for invoke(Integer.class, args).

invokeLong

public long invokeLong(Object[] args)

Convenience method for invoke(Long.class, args).

invokeFloat

public float invokeFloat(Object[] args)

Convenience method for invoke(Float.class, args).

invokeDouble

public double invokeDouble(Object[] args)

Convenience method for invoke(Double.class, args).

invokeVoid

public void invokeVoid(Object[] args)

Convenience method for invoke(Void.class, args).

equals

public boolean equals(Object o)

Two function pointers are equal if they share the same peer address and calling convention.

Setzt außer Kraft:

equals in Klasse Pointer

hashCode

public int hashCode()

Provide a unique hash code for Functions which are equivalent.

Setzt außer Kraft:

hashCode in Klasse Pointer

concatenateVarArgs

static Object[] concatenateVarArgs(Object[] inArgs)

Concatenate varargs with normal args to obtain a simple argument array.

isVarArgs

static boolean isVarArgs(Method m)

Varargs are only supported on 1.5+.

fixedArgs

static int fixedArgs(Method m)

Varargs are only supported on 1.5+.

valueOf

static Boolean valueOf(boolean b)

Implementation of Boolean.valueOf for older VMs.