Java JNI 调用C++ API及中文编码问题

上一篇 / 下一篇 2012-08-10 10:17:05 / 个人分类：Java

)H1pRM6h0z#W1k0　　Java调用C++可以通过JNI声明native方法进行调用，主要步骤有：

　　1、声明类及相关nativ方法，加载要调用的C++库

package bupt.cist.nlp.ner;51Testing软件测试网3K,]5T)]5h

public class ChineseNER {
static{51Testing软件测试网3j7AG;~ AC
System.loadLibrary("CIST_NER");51Testing软件测试网1iR!T}gx
}
public ChineseNER(){
gJAe,?PWY0 }
public native void say(String msg);
jC.k)d1x x W/M3Y0 public native String process(String line);
.`dmse1k*_0}

?U'L,jrS;Q0　　2、到源码目录下，通过命令javah -jni bupt.cist.nlp.ner.ChineseNER编译类，生成.h头文件

/* DO NOT EDIT THIS FILE - it is machine generated */
#include "jni.h"
/* Header for class bupt_cist_nlp_ner_ChineseNER */51Testing软件测试网;U}_0jL

+Y"CMOw3Q/M;bS#v0#ifndef _Included_bupt_cist_nlp_ner_ChineseNER
#define _Included_bupt_cist_nlp_ner_ChineseNER
h o#Z2N3Q&{^0#ifdef __cplusplus51Testing软件测试网M5bQ*B an
extern "C" {
9^3d!xOW#v1|zH0#endif
;}-z4yPVK}+`E0/*
O2_J UI"H1VT.OB0 * Class: bupt_cist_nlp_ner_ChineseNER
* Method: say51Testing软件测试网DIz*}.v#h
* Signature: (Ljava/lang/String;)V
VdD0IR;p|3k0 */51Testing软件测试网2xEv4XU]
JNIEXPORT void JNICALL Java_bupt_cist_nlp_ner_ChineseNER_say51Testing软件测试网S[-Q y,a,mH
(JNIEnv *, jobject, jstring);

;WHusCU|teM0/*
* Class: bupt_cist_nlp_ner_ChineseNER
7d` t9K:L&CRr)BQ0 * Method: process51Testing软件测试网BHW1Do
* Signature: (Ljava/lang/String;)Ljava/lang/String;
+j;Z"FZ.Le3F0 */
n2W`kk%R&~p4c0JNIEXPORT jstring JNICALL Java_bupt_cist_nlp_ner_ChineseNER_process
4n _IX9[7^o/A0 (JNIEnv *, jobject, jstring);

E0J#jiJ0#ifdef __cplusplus51Testing软件测试网kK%N5?7S7T R
}
#endif51Testing软件测试网-TvVyY.v3}
#endif51Testing软件测试网cT9^$H `

\^7|o%[Ca4A:@0　　3、新建CIST_NER的dll工程，加载.h头文件，编写cpp文件实现dll库

#include <iostream>
#include <string>
l}"c7hcd0#include "bupt_cist_nlp_ner_ChineseNER.h"
_+o0gl2G6}2A;E0#include "windows.h"51Testing软件测试网8I*Pbt/v3\'b

]V7k'I5`0using namespace std;

IS7~]!ii YSu ]'n p0char* jstringToWindows( JNIEnv *env, jstring jstr )
{
,X5S)\J3Al0 int length = env->GetStringLength(jstr);
UF5w-[[ _L8W$N WX"mW0 const jchar* jcstr = env->GetStringChars(jstr, 0);
,vpi/STu$_0 char* rtn = (char*)malloc(length*2+1);
int size = 0; 51Testing软件测试网-G9bZ&y"r
size = WideCharToMultiByte(CP_ACP, 0, (LPCWSTR)jcstr, length, rtn,(length*2+1), NULL, NULL);
h [C])n9WH,?R0 if( size <= 0 )
    return NULL;
jB` u:oj'~G[0 env->ReleaseStringChars(jstr, jcstr); 51Testing软件测试网g7M.Kpb*Y
rtn[size] = 0;
'f(x!n0^mS+^"_+l0 return rtn;
}
jstring WindowsTojstring( JNIEnv *env, const char* str ) 51Testing软件测试网K8Xk`0j4p6e
{ 51Testing软件测试网r*Y:[&`d"k!o
jstring rtn = 0;
e7e.GC3EZ}_0 int slen = strlen(str);
unsigned short* buffer = 0;
qs wl+Jk0 if( slen == 0 ) 51Testing软件测试网$sQob7a0nD2~
    rtn = env->NewStringUTF(str);  51Testing软件测试网_a3qN^L{
else 51Testing软件测试网)} lItH1rf
{ 51Testing软件测试网8y&t(@;sA`O
    int length = MultiByteToWideChar(CP_ACP, 0, (LPCSTR)str, slen, NULL, 0);
!e|JKf!M0    buffer = (unsigned short*)malloc(length*2 + 1);
DMy1Bi/Tt0    if( MultiByteToWideChar(CP_ACP, 0, (LPCSTR)str, slen, (LPWSTR)buffer, length) >0)
fa$T` \l*|M x0      rtn = env->NewString((jchar*)buffer, length);
'np^6jM0 }
if(buffer)
free(buffer);
return rtn; 51Testing软件测试网#?re{0[a
} 51Testing软件测试网"E]C5`,y
char* U2G(const char* utf8)
r9DWy'N8E/y0{51Testing软件测试网8A9s7d2l7v5M8@
int len = MultiByteToWideChar(CP_UTF8, 0, utf8, -1, NULL, 0);51Testing软件测试网2Ct*I ]H+k
wchar_t* wstr = new wchar_t[len+1];51Testing软件测试网W;Hv#A f&w.Tb
memset(wstr, 0, len+1);
A&OAO~}D0 MultiByteToWideChar(CP_UTF8, 0, utf8, -1, wstr, len);
len = WideCharToMultiByte(CP_ACP, 0, wstr, -1, NULL, 0, NULL, NULL);
'k!Ux?^8]0 char* str = new char[len+1];51Testing软件测试网[8W mi\.U6oS
memset(str, 0, len+1);
GHh Gge0z0 WideCharToMultiByte(CP_ACP, 0, wstr, -1, str, len, NULL, NULL);
1C2znA)?,}Z0 if(wstr) delete[] wstr;
krw7N:S0 return str;
4B-\if:q5j#n0}
[/y0A1UU$ynU0char* G2U(const char* gb2312)51Testing软件测试网`qG-G)l w&}
{
n.K8a&]8zQ0 int len = MultiByteToWideChar(CP_ACP, 0, gb2312, -1, NULL, 0);
Q4ipkz*l1S0 wchar_t* wstr = new wchar_t[len+1];
$A2B#l6Ara"Wu1z0 memset(wstr, 0, len+1);
)? v4xM$Y9T~ _3v0 MultiByteToWideChar(CP_ACP, 0, gb2312, -1, wstr, len);51Testing软件测试网 Q uE0MF
len = WideCharToMultiByte(CP_UTF8, 0, wstr, -1, NULL, 0, NULL, NULL);51Testing软件测试网-A:f(ne8~-?
char* str = new char[len+1];
u[4` C0o7Zm0 memset(str, 0, len+1);
WideCharToMultiByte(CP_UTF8, 0, wstr, -1, str, len, NULL, NULL);
;n#u:[]3H0 if(wstr) delete[] wstr;
oH%z2m{ Q*GD0 return str;
`7wR5rP0}51Testing软件测试网h(P D O6q3@
JNIEXPORT void JNICALL Java_bupt_cist_nlp_ner_ChineseNER_say(JNIEnv *env, jobject obj, jstring msg)
}tc$S(F/k0{
const char* pmsg = env->GetStringUTFChars(msg, NULL);
'j*w'Cjo9? P0 cout << pmsg << endl;
}51Testing软件测试网t)TMY cJ^
JNIEXPORT jstring JNICAL Java_bupt_cist_nlp_ner_ChineseNER_process(JNIEnv *env, jobject obj, jstring line)
bt Y?Ot3qX0{51Testing软件测试网#Z9M}*\#R
const char* pmsg = jstringToWindows(env, line);
*h"SS5G[/v ?0 cout << pmsg << endl;51Testing软件测试网Y%Tf2P i
// process
    return WindowsTojstring(env, res.c_str());
#u-diHdTH0}51Testing软件测试网AZp`3[

　　4、编译生成dll库，放在java工程目录下即可调用

package cpp;51Testing软件测试网Z*_1CQG b

DSdoNA,ixL%n0import bupt.cist.nlp.ner.*;
/p,^n:hZDPq0public class test {

/**
5YrWk/U3D_2Ck0 * @param args
;xB,gQX'h s7h0I0 */
public static void main(String[] args) {
&XdH4^Z'H0  // TODO Auto-generated method stub
z.X9KX!KGT0  ChineseNER a = new ChineseNER();
  String line = "星期一中国北京";
K4w7ye/l.w0  System.out.println(line);
[u[ I"?Bv0  String b = a.process(line);
^9~ ^!|4JD0  a.say(b);51Testing软件测试网t4V4b\+V#{I
}51Testing软件测试网 C8eDw-p
}

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