jna 解决乱码 GBK

如何使用java调用dll?

一般是用jni直接来调用dll的接口.因为中文乱码,GBK,utf-8等一系列原因,我选择了用jna这个第三方接口来.

Dll放的位置:可以放在项目的根目录下,可以放在jdk目录中的bin目录下.这两个地方jna都是可以找到的.

因为调用的过程中设计了中文,dll中的中文是用GBK进行编码的,所以java传给dll也得是GBK,不然就会乱码.因为c,c++中的char*对应java中的string,不过jna默认的编码方式是utf-8,所以要手动的将编码方式改为GBK.

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System.setProperty("jna.encoding","GBK");

c,c++对应java中的类型如下:

C Type	Native Representation	Java Type
char	8-bit integer	byte
wchar_t	platform-dependent	char
short	16-bit integer	short
int	32-bit integer	int
int	boolean flag	boolean
enum	enumeration type	int (usually)
long long, __int64	64-bit integer	long
float	32-bit floating point	float
double	64-bit floating point	double
pointer (e.g. void*)	platform-dependent (32- or 64-bit pointer to memory)	Buffer Pointer
pointer (e.g. void*), array	32- or 64-bit pointer to memory (argument/return) contiguous memory (struct member)	<P>[] (array of primitive type)
In addition to the above types, which are supported at the native layer, the JNA Java library automatically handles the following types. All but NativeMapped and NativeLong are converted to Pointer before being passed to the native layer.
long	platform-dependent (32- or 64-bit integer)	NativeLong
const char*	NUL-terminated array (native encoding or jna.encoding)	String
const wchar_t*	NUL-terminated array (unicode)	WString
char**	NULL-terminated array of C strings	String[]
wchar_t**	NULL-terminated array of wide C strings	WString[]
void**	NULL-terminated array of pointers	Pointer[]
struct* struct	pointer to struct (argument or return) (or explicitly) struct by value (member of struct) (or explicitly)	Structure
union	same as Structure	Union
struct[]	array of structs, contiguous in memory	Structure[]
void (*FP)()	function pointer (Java or native)	Callback
pointer (<T> *)	same as Pointer	PointerType
other	integer type	IntegerType
other	custom mapping, depends on definition	NativeMapped

获取double*指针返回的数据,char*的返回数据.

对于函数原型为

const char*fszSimilarArticle( int iIndex, double *pSimilarity );

其中pSimilarity是返回的数据,c,c++语言经常这样子进行返回数据.

对应的java原型:

StringfszSimilarArticle(int iIndex,Memory pSimilarity);

使用 jna-4.0.0.jar

调用方式:

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Double pSimilarity = null;

Memory memory_sililar = new Memory(8);

String articleId_section = fszSimilarArticle(iIndex,memory_sililar);

pSimilarity=memory_sililar.getDouble(0);

这样可以获取返回数据.

创建对应的接口:

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package netinet.thesis.release;

importcom.sun.jna.Library;

importcom.sun.jna.Memory;

importcom.sun.jna.Native;

public MOD extends Library {

/*mean语义分析*/

public final static String CHECK_MEAN = "0";

/*order词序分析*/

public final static String CHECK_ORDER = "1";

public int fnVersion(Memory CheckArticle);

public String fszSimilarArticle(intiIndex,Memory pSimilarity);

}

创建实例的方式:

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public static MOD newThesisMod(){

System.setProperty("jna.encoding","GBK"); //如果不适用GBK进行编码,则改为对应的编码方式.

return (MOD)Native.loadLibrary("MOD",MOD.class);

}

jar包下载

http://download.csdn.net/detail/w329636271/8846031

github官网: http://twall.github.io/jna/3.4.0/javadoc/overview-summary.html

如何创建一个dll: /article/8815249.html

Api: https://jna.java.net/javadoc/com/sun/jna/Memory.html

参考: /article/3943044.html

转载于：http://blog.csdn.net/w329636271/article/details/46665239