JNI各类型参数互相调用

た入场券 2022-08-23 00:36 192阅读 0赞

1、java 传入的String 在 C 中转化为 char\*打印出来

jstring obj；

const char\* string = (char\*)(\*env)->GetStringUTFChars(env,obj,NULL);

\_\_android\_log\_print(ANDROID\_LOG\_INFO, "JNIMsg",string);

2、'for' loop initial declarations are only allowed in C99 mode 错误

int i = 0;

for (; i < size; i++) \{\}

需要把int i 定义在前面

3、取得数组中下标为 i 的元素

jobject obj= ((\*env)->GetObjectArrayElement(env, array, i));

4、JNI定义字符串数组并给字符串数组赋值

jobjectArray arrays = 0; 
//定义长度 
jsize len = 20; 
arrays = (\*jniEnv)->NewObjectArray(jniEnv, len, (\*jniEnv)->FindClass( 
 jniEnv, "java/lang/String"), 0); 
 
jstring jstr; 
char\* sa\[\] = \{ "Hello,", "world!", "JNI", "很", "好玩" \}; 
int i = 0; 
for (; i < len; i++) 
\{ 
 jstr = (\*env)->NewStringUTF(env, sa\[i\]); 
 (\*env)->SetObjectArrayElement(env, arrays, i, jstr);//必须放入jstring 
\}

5、获取数组的值

int k = 0; 
for (; k < len; k++) \{ 
jstring string = (jstring)((\*jniEnv)->GetObjectArrayElement(jniEnv, 
 arrays, k)); 
if (string != NULL) \{ 
char \* c = (\*jniEnv)->GetStringUTFChars(jniEnv, string, 0); 
\_\_android\_log\_print(ANDROID\_LOG\_INFO, "JNIMsg", c); 
\} 
\}

6、中间层数据类型转化

char\* ---> jstring (\*jniEnv)->NewStringUTF(jniEnv,char\*)  
jstring ---> char (\*jniEnv)->GetStringUTFChars(jniEnv, jstring, 0);  
long ---> char\* ltoa(long,char\*,10); sprintf(csendBodyLen,"%ld",sendBodyLen);  
char\* ---> long \*long = atol(char\*);

### jni和java之间字符串的转换方法。   　　C的实现:   　　JNIEXPORTjstring JNICALL Java\_Android123\_CwjC (JNIEnv \*env, jobject obj,jstring string)   　　\{   　　　charszBuffer\[255\];   　　　return(\*env)->NewStringUTF(env, szBuffer);   　　\}   　　C++的实现:   　　JNIEXPORTjstring JNICALL Java\_Android123\_CwjCpp (JNIEnv \*env, jobject obj,jstring string)   　　\{   　　constchar \*strUTF = env->GetStringUTFChars(string,0);   　　charszBuffer\[255\];   　　strcpy(szBuffer,strUTF);   　　env->ReleaseStringUTFChars(string,strUTF);   　　returnenv->NewStringUTF(szBuffer);   　　\} ###

### java中string与byte\[\]的转换  ###

1.string 转 byte\[\]

byte\[\]midbytes=isoString.getBytes("UTF8");

//为UTF8编码

byte\[\]isoret = srt2.getBytes("ISO-8859-1");

//为ISO-8859-1编码

其中ISO-8859-1为单字节的编码

2.byte\[\]转string

StringisoString = new String(bytes,"ISO-8859-1");

Stringsrt2=new String(midbytes,"UTF-8");

<table> 
 <tbody> 
 <tr> 
 <td colspan="2"> //jbytearray转c++byte数组 </td> 
 </tr> 
 <tr> 
 <td> </td> 
 <td colspan="2"> jbyte * arrayBody =env-&gt;GetByteArrayElements(data,0); </td> 
 </tr> 
 <tr> 
 <td> </td> 
 <td> </td> 
 <td> </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 3 </td> 
 <td colspan="2"> jsize theArrayLengthJ = env-&gt;GetArrayLength(data); </td> 
 </tr> 
 <tr> 
 <td> 4 </td> 
 <td> BYTE * starter = (BYTE *)arrayBody; </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 1 </td> 
 <td colspan="2"> //jbyteArray 转 c++中的BYTE[] </td> 
 </tr> 
 <tr> 
 <td> 2 </td> 
 <td> //jbytearray array </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 3 </td> 
 <td colspan="2"> jbyte * olddata = (jbyte*)env-&gt;GetByteArrayElements(array,0); </td> 
 </tr> 
 <tr> 
 <td> 4 </td> 
 <td> jsize&nbsp; oldsize =env-&gt;GetArrayLength(array); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 5 </td> 
 <td colspan="2"> BYTE* bytearr = (BYTE*)olddata; </td> 
 </tr> 
 <tr> 
 <td> 6 </td> 
 <td> int len = (int)oldsize; </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 1 </td> 
 <td> //C++中的BYTE[]转jbyteArray </td> 
 </tr> 
 <tr> 
 <td> 2 </td> 
 <td colspan="2"> //nOutSize是BYTE数组的长度BYTE pData[] </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 3 </td> 
 <td> jbyte *by = (jbyte*)pData; </td> 
 </tr> 
 <tr> 
 <td> 4 </td> 
 <td colspan="2"> jbyteArray jarray = env-&gt;NewByteArray(nOutSize); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 5 </td> 
 <td> env-&gt;SetByteArrayRegin(jarray, 0, nOutSize, by); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 1 </td> 
 <td> //jbyteArray 转 char * </td> 
 </tr> 
 <tr> 
 <td> 2 </td> 
 <td colspan="2"> char* data = (char*)env-&gt;GetByteArrayElements(strIn,0); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 1 </td> 
 <td> //char* 转jstring </td> 
 </tr> 
 <tr> 
 <td> 2 </td> 
 <td colspan="2"> jstring WindowsTojstring(JNIEnv* env, char* str_tmp) </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 3 </td> 
 <td> { </td> 
 </tr> 
 <tr> 
 <td> 4 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;jstringrtn=0; </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 5 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;intslen = (int)strlen(str_tmp); </td> 
 </tr> 
 <tr> 
 <td> 6 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;unsignedshort* buffer=0; </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 9 </td> 
 <td colspan="3"> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;rtn= env-&gt;NewStringUTF(str_tmp); </td> 
 </tr> 
 <tr> 
 <td colspan="2"> 10 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;} </td> 
 </tr> 
 <tr> 
 <td> </td> 
 <td> </td> 
 <td> </td> 
 <td> </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 13 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;intlength = MultiByteToWideChar(CP_ACP, 0, (LPCSTR)str_tmp, slen,NULL, 0); </td> 
 </tr> 
 <tr> 
 <td> 14 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;buffer= (unsigned short*)malloc(length*2+1); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 15 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(MultiByteToWideChar(CP_ACP,0, (LPCSTR)str_tmp, slen, (LPWSTR)buffer, length) &gt;0) </td> 
 </tr> 
 <tr> 
 <td> 16 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{ </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 17 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;rtn= env-&gt;NewString((jchar*)buffer, length); </td> 
 </tr> 
 <tr> 
 <td> 18 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;} </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 19 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;} </td> 
 </tr> 
 <tr> 
 <td> 20 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;if(buffer) </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 21 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;{ </td> 
 </tr> 
 <tr> 
 <td> 22 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;free(buffer); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 23 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;} </td> 
 </tr> 
 <tr> 
 <td> 24 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;returnrtn; </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 1 </td> 
 <td colspan="2"> //jstring 转 char* 或者 constchar* </td> 
 </tr> 
 <tr> 
 <td> 2 </td> 
 <td> // jstring str </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 3 </td> 
 <td colspan="2"> const char *key = env-&gt;GetStringUTFChars(str, 0); </td> 
 </tr> 
 <tr> 
 <td> 4 </td> 
 <td> //jboolean isOffer </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 5 </td> 
 <td colspan="2"> jsClient-&gt;modify(key, isOffer); </td> 
 </tr> 
 <tr> 
 <td> 6 </td> 
 <td> //需要释放，否则容易内存泄露 </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 7 </td> 
 <td> env-&gt;ReleaseStringUTFChars(str, key); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 1 </td> 
 <td> //JNI 返回 jbyteArray </td> 
 </tr> 
 <tr> 
 <td> 2 </td> 
 <td colspan="2"> JNIEXPORT jbyteArray JNICALL Java_Test_getByteArray(JNIEnv *env,jobject obj) </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 3 </td> 
 <td> { </td> 
 </tr> 
 <tr> 
 <td> 4 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;jbyteArrayfirstMacArray = env-&gt;NewByteArray( 6 ); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 5 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;...... </td> 
 </tr> 
 <tr> 
 <td> 6 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;jbyte*bytes = env-&gt;GetByteArrayElements( firstMacArray,0); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 7 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;for( int i = 0; i &lt; sizeof( pAdapterInfo-&gt;Address ); i++ ) </td> 
 </tr> 
 <tr> 
 <td> 8 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;{ </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 9 </td> 
 <td colspan="3"> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;bytes[i ] = pAdapterInfo-&gt;Address[ i ]; </td> 
 </tr> 
 <tr> 
 <td colspan="2"> 10 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;} </td> 
 </tr> 
 <tr> 
 <td> </td> 
 <td> </td> 
 <td> </td> 
 <td> </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 11 </td> 
 <td> &nbsp; </td> 
 </tr> 
 <tr> 
 <td> 12 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;env-&gt;SetByteArrayRegion(firstMacArray,0, 6, bytes ); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td colspan="2"> 13 </td> 
 <td colspan="3"> &nbsp;&nbsp;&nbsp;&nbsp;returnfirstMacArray; </td> 
 </tr> 
 <tr> 
 <td colspan="2"> 14 </td> 
 <td colspan="2"> } </td> 
 </tr> 
 <tr> 
 <td> 1 </td> 
 <td colspan="2"> //jstring to char* </td> 
 </tr> 
 <tr> 
 <td> </td> 
 <td> </td> 
 <td> </td> 
 <td> </td> 
 <td> </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 2 </td> 
 <td colspan="2"> char* jstringTostring(JNIEnv* env, jstring jstr) </td> 
 </tr> 
 <tr> 
 <td> 3 </td> 
 <td> {&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 4 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;char*rtn = NULL; </td> 
 </tr> 
 <tr> 
 <td> 5 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;jclassclsstring = env-&gt;FindClass("java/lang/String"); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 6 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;jstringstrencode = env-&gt;NewStringUTF("utf-8"); </td> 
 </tr> 
 <tr> 
 <td> 7 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;jmethodIDmid = env-&gt;GetMethodID(clsstring, "getBytes","(Ljava/lang/String;)[B"); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 8 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;jbyteArraybarr= (jbyteArray)env-&gt;CallObjectMethod(jstr, mid,strencode); </td> 
 </tr> 
 <tr> 
 <td> 9 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;jsizealen = env-&gt;GetArrayLength(barr); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 10 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;jbyte*ba = env-&gt;GetByteArrayElements(barr, JNI_FALSE); </td> 
 </tr> 
 <tr> 
 <td> 11 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;if(alen &gt; 0) </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 12 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;{ </td> 
 </tr> 
 <tr> 
 <td> 13 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;rtn= (char*)malloc(alen + 1); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 14 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;memcpy(rtn,ba, alen); </td> 
 </tr> 
 <tr> 
 <td> 15 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;rtn[alen]= 0; </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 16 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;} </td> 
 </tr> 
 <tr> 
 <td> 17 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;env-&gt;ReleaseByteArrayElements(barr,ba, 0); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 18 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;returnrtn; </td> 
 </tr> 
 <tr> 
 <td> 19 </td> 
 <td> } </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 1 </td> 
 <td> char* to jstring </td> 
 </tr> 
 <tr> 
 <td> 2 </td> 
 <td colspan="2"> jstring stoJstring(JNIEnv* env, const char* pat) </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 3 </td> 
 <td> { </td> 
 </tr> 
 <tr> 
 <td> 4 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;jclassstrClass = env-&gt;FindClass("Ljava/lang/String;"); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 5 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;jmethodIDctorID = env-&gt;GetMethodID(strClass, "","([BLjava/lang/String;)V"); </td> 
 </tr> 
 <tr> 
 <td> 6 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;jbyteArraybytes = env-&gt;NewByteArray(strlen(pat)); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 7 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;env-&gt;SetByteArrayRegion(bytes,0, strlen(pat), (jbyte*)pat); </td> 
 </tr> 
 <tr> 
 <td> 8 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;jstringencoding = env-&gt;NewStringUTF("utf-8"); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 9 </td> 
 <td colspan="3"> &nbsp;&nbsp;&nbsp;&nbsp;return(jstring)env-&gt;NewObject(strClass, ctorID, bytes,encoding); </td> 
 </tr> 
 <tr> 
 <td colspan="2"> 10 </td> 
 <td> } </td> 
 </tr> 
 <tr> 
 <td> </td> 
 <td> </td> 
 <td> </td> 
 <td> </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 1 </td> 
 <td> //将jstring类型转换成windows类型 </td> 
 </tr> 
 <tr> 
 <td> 2 </td> 
 <td colspan="2"> char* jstringToWindows( JNIEnv *env, jstring jstr ) </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 3 </td> 
 <td> { </td> 
 </tr> 
 <tr> 
 <td> 4 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;intlength = (env)-&gt;GetStringLength(jstr ); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 5 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;constjchar* jcstr = (env)-&gt;GetStringChars(jstr, 0 ); </td> 
 </tr> 
 <tr> 
 <td> 6 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;char*rtn = (char*)malloc( length*2+1 ); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 7 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;intsize = 0; </td> 
 </tr> 
 <tr> 
 <td> 8 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;size= WideCharToMultiByte( CP_ACP, 0, (LPCWSTR)jcstr, length,rtn,(length*2+1), NULL, NULL ); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 9 </td> 
 <td colspan="3"> &nbsp;&nbsp;&nbsp;&nbsp;if(size &lt;= 0 ) </td> 
 </tr> 
 <tr> 
 <td colspan="2"> 10 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;returnNULL; </td> 
 </tr> 
 <tr> 
 <td> </td> 
 <td> </td> 
 <td> </td> 
 <td> </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 1 </td> 
 <td> //将windows类型转换成jstring类型 </td> 
 </tr> 
 <tr> 
 <td> 2 </td> 
 <td colspan="2"> jstring WindowsTojstring( JNIEnv* env, char* str ) </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 5 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;intslen = strlen(str); </td> 
 </tr> 
 <tr> 
 <td> 6 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;unsignedshort * buffer = 0; </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 7 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;if(slen == 0 ) </td> 
 </tr> 
 <tr> 
 <td> 8 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;rtn= (env)-&gt;NewStringUTF(str ); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 11 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;intlength = MultiByteToWideChar( CP_ACP, 0, (LPCSTR)str, slen, NULL, 0); </td> 
 </tr> 
 <tr> 
 <td> 12 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;buffer= (unsigned short *)malloc( length*2 + 1 ); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 13 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(MultiByteToWideChar( CP_ACP, 0, (LPCSTR)str, slen, (LPWSTR)buffer,length ) &gt;0 ) </td> 
 </tr> 
 <tr> 
 <td> 14 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;rtn= (env)-&gt;NewString( (jchar*)buffer, length ); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 15 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;} </td> 
 </tr> 
 <tr> 
 <td> 16 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;if(buffer ) </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 17 </td> 
 <td colspan="2"> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;free(buffer ); </td> 
 </tr> 
 <tr> 
 <td> 18 </td> 
 <td> &nbsp;&nbsp;&nbsp;&nbsp;returnrtn; </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 1 </td> 
 <td> //从传进来的对象中取出byte[] </td> 
 </tr> 
 <tr> 
 <td> 2 </td> 
 <td colspan="2"> jfieldID byteData =(env)-&gt;GetFieldID(clazz,"bData","[B"); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 3 </td> 
 <td colspan="2"> jbyteArray pDataIn = (jbyteArray)(env)-&gt;GetObjectField(objDataIn, byteData); </td> 
 </tr> 
 <tr> 
 <td> 4 </td> 
 <td> jsize theArrayLeng = env-&gt;GetArrayLength(pDataIn); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 1 </td> 
 <td> //byte[]转为BYTE[] </td> 
 </tr> 
 <tr> 
 <td> 2 </td> 
 <td colspan="2"> jbyte * arrayBody =env-&gt;GetByteArrayElements(pDataIn,0); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 3 </td> 
 <td> BYTE * jDataIn = (BYTE *)arrayBody; </td> 
 </tr> 
 </tbody> 
</table>

JNI开发交流 C/C++,JAVA，android，linux/unix QQ群：25093009

<table> 
 <tbody> 
 <tr> 
 <td> 1 </td> 
 <td> //将BYTE数组转为jarray </td> 
 </tr> 
 <tr> 
 <td> 2 </td> 
 <td colspan="2"> jbyte* byte =(jbyte*)jDataOut;&nbsp;&nbsp;&nbsp; </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 3 </td> 
 <td> jbyteArray jarray = env-&gt;NewByteArray(theArrayLeng); </td> 
 </tr> 
 <tr> 
 <td> 4 </td> 
 <td colspan="2"> env-&gt;SetByteArrayRegion(jarray, 0, theArrayLeng,byte); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 1 </td> 
 <td> //给每一个实例的变量付值 </td> 
 </tr> 
 <tr> 
 <td> 2 </td> 
 <td colspan="2"> (env)-&gt;SetObjectField(objDataIn,byteData,jarray); </td> 
 </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
 <tr> 
 <td> 3 </td> 
 <td> (env)-&gt;SetIntField(objDataIn,pDataInLen,jDataInLen); </td> 
 </tr> 
 <tr> 
 <td> 4 </td> 
 <td colspan="2"> (env)-&gt;ReleaseByteArrayElements(pDataIn, arrayBody,0); </td> 
 </tr> 
 </tbody> 
</table>