某些数组和字符串类型转换（转）__字符串数组转换为int数组

相关文章推荐

小胡子的皮带 · C# 中的ushort - CSDN文库· 2 月前 ·

完美的苹果 · 安克创新25届校招CATA北森测评：笔试攻略 ...· 2 月前 ·

玩篮球的西装 · 伍慧萍：从汉堡的产业集群战略看德国地方政府的 ...· 4 月前 ·

干练的打火机 · 渝昆高铁川渝段全线贯通_手机新浪网· 1 年前 ·

温文尔雅的蘑菇 · 《极地恶灵 ...· 1 年前 ·

骑白马的开水瓶 · ν姬 - 萌娘百科万物皆可萌的百科全书· 1 年前 ·

jbytearray转c++byte数组

1 jbyte * arrayBody = env->GetByteArrayElements(data,0);   
2 jsize theArrayLengthJ = env->GetArrayLength(data);   
3 BYTE * starter = (BYTE *)arrayBody;

jbyteArray 转 c++中的BYTE[]

1 //jbytearray strIn  
2 jbyte * olddata = (jbyte*)env->GetByteArrayElements(strIn, 0);  
3 jsize  oldsize = env->GetArrayLength(strIn);  
4 BYTE* bytearr = (BYTE*)olddata;  
5 int len = (int)oldsize;

C++中的BYTE[]转jbyteArray

1 //nOutSize是BYTE数组的长度 BYTE pData[]  
2 jbyte *by = (jbyte*)pData;  
3 jbyteArray jarray = env->NewByteArray(nOutSize);  
4 env->SetByteArrayRegin(jarray, 0, nOutSize, by);

jbyteArray 转 char *

char* data = (char*)env->GetByteArrayElements(strIn, 0);

char* 转jstring

1 jstring WindowsTojstring(JNIEnv* env, char* str_tmp) 2 { 3 jstring rtn=0; 4 int slen = (int)strlen(str_tmp); 5 unsigned short* buffer=0; 6 if(slen == 0) 8 rtn = env->NewStringUTF(str_tmp); 10 else 11 { 12 int length = MultiByteToWideChar(CP_ACP, 0, (LPCSTR)str_tmp, slen, NULL, 0); 13 buffer = (unsigned short*)malloc(length*2+1); 14 if(MultiByteToWideChar(CP_ACP, 0, (LPCSTR)str_tmp, slen, (LPWSTR)buffer, length) > 0) 15 { 16 rtn = env->NewString((jchar*)buffer, length); 17 } 18 } 19 if(buffer) 20 { 21 free(buffer); 22 } 23 return rtn;

下面这个没有用过，刚看到，也写进来，以后如果遇到可以验证下看。

jstring 转 char* 或者 const char*

1 // jstring str  
2 const char *key = env->GetStringUTFChars(str, 0);  
3 //jboolean isOffer  
4 jsClient->modify(key, isOffer);  
5 env->ReleaseStringUTFChars(str, key);

JNI 返回 jbyteArray

1 JNIEXPORT jbyteArray JNICALL Java_Test_getByteArray(JNIEnv *env, jobject obj)  
 2 {  
 3     jbyteArray firstMacArray = env->NewByteArray( 6 );  
 4     ......  
 5     jbyte *bytes = env->GetByteArrayElements( firstMacArray, 0);  
 6     for ( int i = 0; i < sizeof( pAdapterInfo->Address ); i++ )  
 7     {  
 8        bytes[ i ] = pAdapterInfo->Address[ i ];  
 9     }  
10   
11     env->SetByteArrayRegion(firstMacArray, 0, 6, bytes );  
12     return firstMacArray;  
13 }

//jstring to char*

1 char* jstringTostring(JNIEnv* env, jstring jstr)  
 2 {          
 3   char* rtn = NULL;  
 4   jclass clsstring = env->FindClass("java/lang/String");  
 5   jstring strencode = env->NewStringUTF("utf-8");  
 6   jmethodID mid = env->GetMethodID(clsstring, "getBytes", "(Ljava/lang/String;)[B");  
 7   jbyteArray barr= (jbyteArray)env->CallObjectMethod(jstr, mid, strencode);  
 8   jsize alen = env->GetArrayLength(barr);  
 9   jbyte* ba = env->GetByteArrayElements(barr, JNI_FALSE);  
10   if (alen > 0)  
11   {  
12     rtn = (char*)malloc(alen + 1);  
13     memcpy(rtn, ba, alen);  
14     rtn[alen] = 0;  
15   }  
16   env->ReleaseByteArrayElements(barr, ba, 0);  
17   return rtn;  
18 }

//char* to jstring

1 jstring stoJstring(JNIEnv* env, const char* pat)  
2 {  
3 jclass strClass = env->FindClass("Ljava/lang/String;");  
4 jmethodID ctorID = env->GetMethodID(strClass, "<init>", "([BLjava/lang/String;)V");  
5 jbyteArray bytes = env->NewByteArray(strlen(pat));  
6 env->SetByteArrayRegion(bytes, 0, strlen(pat), (jbyte*)pat);  
7 jstring encoding = env->NewStringUTF("utf-8");  
8 return (jstring)env->NewObject(strClass, ctorID, bytes, encoding);  
9 }

//将jstring类型转换成windows类型

1 char* jstringToWindows( JNIEnv *env, jstring jstr )  
 2 {  
 3 int length = (env)->GetStringLength(jstr );  
 4 const jchar* jcstr = (env)->GetStringChars(jstr, 0 );  
 5 char* rtn = (char*)malloc( length*2+1 );  
 6 int size = 0;  
 7 size = WideCharToMultiByte( CP_ACP, 0, (LPCWSTR)jcstr, length, rtn,(length*2+1), NULL, NULL );  
 8 if( size <= 0 )  
 9 return NULL;  
10 (env)->ReleaseStringChars(jstr, jcstr );  
11 rtn[size] = 0;  
12 return rtn;  
13 }

//将windows类型转换成jstring类型

1 jstring WindowsTojstring( JNIEnv* env, char* str )  
 2 {  
 3 jstring rtn = 0;  
 4 int slen = strlen(str);  
 5 unsigned short * buffer = 0;  
 6 if( slen == 0 )  
 7 rtn = (env)->NewStringUTF(str );  
 8 else  
 9 {  
10 int length = MultiByteToWideChar( CP_ACP, 0, (LPCSTR)str, slen, NULL, 0 );  
11 buffer = (unsigned short *)malloc( length*2 + 1 );  
12 if( MultiByteToWideChar( CP_ACP, 0, (LPCSTR)str, slen, (LPWSTR)buffer, length ) >0 )  
13 rtn = (env)->NewString( (jchar*)buffer, length );  
14 }  
15 if( buffer )  
16 free( buffer );  
17 return rtn;  
18 }  
19 /*JNIEXPORT jstring JNICALL Java_test_cs_web_SWIFTAlianceCASmfTest_strcal 
20 (JNIEnv *env, jclass obj, jstring jstr1, jstring jstr2) 
21 { 
22 jbyteArray bytes = 0; 
23 jthrowable exc; 
24 char *pszResult = NULL;     
25 char *pszSTR1 = NULL; 
26 char *pszSTR2 = NULL; 
27  
28 pszSTR1 = jstringTostring(env, jstr1); 
29 pszSTR2 = jstringTostring(env, jstr2); 
30  
31  
32 int nlen = sizeof(char)*(strlen(pszSTR1)+strlen(pszSTR2)); 
33 pszResult = (char*)malloc(nlen); 
34 strcpy(pszResult, pszSTR1); 
35 strcat(pszResult, pszSTR2); 
36  
37 jstring jstrRe = stoJstring(env, pszResult); 
38 free(pszSTR1); 
39 free(pszSTR2); 
40 free(pszResult); 
41 return(jstrRe); 
42 } 
43 */

jni object的使用

每一个jni格式的dll中的object对应该java里面的一个类。

如下例有一个 ObjData类，类中有成员bData ,Len

public class ObjData {

public byte[] bData;

public int Len;

}

//------------------------jni获得传过来的Object类型的变量objDataIn--------

jclass clazz =(env)->FindClass("ObjData");

//从传进来的对象中取出byte[]

1 jfieldID byteData = (env)->GetFieldID(clazz,"bData","[B");  
2 jbyteArray pDataIn = (jbyteArray) (env)->GetObjectField(objDataIn, byteData);  
3 jsize theArrayLeng = env->GetArrayLength(pDataIn);

//byte[]转为BYTE[]

1 jbyte * arrayBody = env->GetByteArrayElements(pDataIn,0);   
2 BYTE * jDataIn = (BYTE *)arrayBody;

//将BYTE数组转为jarray

1 jbyte* byte = (jbyte*)jDataOut;      
2 jbyteArray jarray = env->NewByteArray(theArrayLeng);  
3 env->SetByteArrayRegion(jarray, 0, theArrayLeng, byte);

//给每一个实例的变量付值

1 (env)->SetObjectField(objDataIn,byteData,jarray);  
2 (env)->SetIntField(objDataIn,pDataInLen,jDataInLen);  
3 (env)->ReleaseByteArrayElements(pDataIn, arrayBody, 0);