Quick Reference

The following two tables list the native type that corresponds to each Java type. The first table describes the mappings for parameters and return values, and the second table shows the mappings that are used with the @dll.struct directive.

Parameter and Return Value Mappings

Java	Native	Notes/Restrictions
byte	BYTE or CHAR
short	SHORT or WORD
int	INT, UINT, LONG, ULONG, or DWORD
char	TCHAR
long	__int64
float	float
double	double
boolean	BOOL
String	LPCTSTR	Not allowed as return value, except in ole mode. In ole mode, String maps to LPWSTR. The Microsoft VM frees the string by using CoTaskMemFree.
StringBuffer	LPTSTR	Not allowed as return value. Set the StringBuffer capacity large enough to hold the largest string that the DLL function can generate.
byte[]	BYTE*
short[]	WORD*
char[]	TCHAR*
int[]	DWORD*
float[]	float*
double[]	double*
long[]	__int64*
boolean[]	BOOL[]
Object	pointer to struct	In ole mode, an IUnknown* is passed instead.
Interface	COM interface	Use jactivex or similar tool to generate interface file.
com.ms.com.SafeArray	SAFEARRAY*	Not allowed as return value.
com.ms.com._Guid	GUID,IID,CLSID
com.ms.com.Variant	VARIANT*
@dll.struct classes	pointer to struct
@com.struct classes	pointer to struct
void	VOID	As return value only.
com.ms.dll.Callback	function pointer	As parameter only.

Mappings used with @dll.struct

Java	Native
byte	BYTE or CHAR
char	TCHAR
short	SHORT or WORD
int	INT, UINT, LONG, ULONG or DWORD
float	__int64
long	float
double	double
boolean	BOOL[]
Java	Native
String	Pointer to a string, or an embedded fixed-size string
Class marked with @dll.struct	Nested structure
char[]	Nested array of TCHAR
byte[]	Nested array of BYTE
short[]	Nested array of SHORT
int[]	Nested array of LONG
long[]	Nested array of __int64
float[]	Nested array of floats
double[]	Nested array of doubles