java string(byte[])_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
String isoString = new String(bytes,"ISO-8859-1");
String srt2=new String(midbytes,"UTF-8");
//jbytearray转c++byte数组
jbyte * arrayBody = env->GetByteArrayElements(data,0);
3
jsize theArrayLengthJ = env->GetArrayLength(data);
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BYTE * starter = (BYTE *)arrayBody;
1
//jbyteArray 转 c++中的BYTE[]
2
//jbytearray array
3
jbyte * olddata = (jbyte*)env->GetByteArrayElements(array, 0);
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jsize oldsize = env->GetArrayLength(array);
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BYTE* bytearr = (BYTE*)olddata;
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int len = (int)oldsize;
1
//C++中的BYTE[]转jbyteArray
2
//nOutSize是BYTE数组的长度 BYTE pData[]
3
jbyte *by = (jbyte*)pData;
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jbyteArray jarray = env->NewByteArray(nOutSize);
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env->SetByteArrayRegin(jarray, 0, nOutSize, by);
1
//jbyteArray 转 char *
2
char* data = (char*)env->GetByteArrayElements(strIn, 0);
1
//char* 转jstring
2
jstring WindowsTojstring(JNIEnv* env, char* str_tmp)
3
{
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jstring rtn=0;
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int slen = (int)strlen(str_tmp);
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unsigned short* buffer=0;
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if(slen == 0)
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{
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rtn = env->NewStringUTF(str_tmp);
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}
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else
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{
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int length = MultiByteToWideChar(CP_ACP, 0, (LPCSTR)str_tmp, slen, NULL, 0);
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buffer = (unsigned short*)malloc(length*2+1);
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if(MultiByteToWideChar(CP_ACP, 0, (LPCSTR)str_tmp, slen, (LPWSTR)buffer, length) > 0)
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{
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rtn = env->NewString((jchar*)buffer, length);
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}
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}
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if(buffer)
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{
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free(buffer);
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}
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return rtn;
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}
1
//jstring 转 char* 或者 const char*
2
// jstring str
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const char *key = env->GetStringUTFChars(str, 0);
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//jboolean isOffer
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jsClient->modify(key, isOffer);
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//需要释放，否则容易内存泄露
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env->ReleaseStringUTFChars(str, key);
1
//JNI 返回 jbyteArray
2
JNIEXPORT jbyteArray JNICALL Java_Test_getByteArray(JNIEnv *env, jobject obj)
3
{
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jbyteArray firstMacArray = env->NewByteArray( 6 );
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......
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jbyte *bytes = env->GetByteArrayElements( firstMacArray, 0);
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for ( int i = 0; i < sizeof( pAdapterInfo->Address ); i++ )
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{
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bytes[ i ] = pAdapterInfo->Address[ i ];
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}
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env->SetByteArrayRegion(firstMacArray, 0, 6, bytes );
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return firstMacArray;
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}
1
//jstring to char*
2
char* jstringTostring(JNIEnv* env, jstring jstr)
3
{
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char* rtn = NULL;
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jclass clsstring = env->FindClass("java/lang/String");
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jstring strencode = env->NewStringUTF("utf-8");
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jmethodID mid = env->GetMethodID(clsstring, "getBytes", "(Ljava/lang/String;)[B");
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jbyteArray barr= (jbyteArray)env->CallObjectMethod(jstr, mid, strencode);
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jsize alen = env->GetArrayLength(barr);
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jbyte* ba = env->GetByteArrayElements(barr, JNI_FALSE);
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if (alen > 0)
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{
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rtn = (char*)malloc(alen + 1);
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memcpy(rtn, ba, alen);
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rtn[alen] = 0;
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}
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env->ReleaseByteArrayElements(barr, ba, 0);
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return rtn;
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}
1
char* to jstring
2
jstring stoJstring(JNIEnv* env, const char* pat)
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{
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jclass strClass = env->FindClass("Ljava/lang/String;");
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jmethodID ctorID = env->GetMethodID(strClass, "", "([BLjava/lang/String;)V");
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jbyteArray bytes = env->NewByteArray(strlen(pat));
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env->SetByteArrayRegion(bytes, 0, strlen(pat), (jbyte*)pat);
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jstring encoding = env->NewStringUTF("utf-8");
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return (jstring)env->NewObject(strClass, ctorID, bytes, encoding);
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}
1
//将jstring类型转换成windows类型
2
char* jstringToWindows( JNIEnv *env, jstring jstr )
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{
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int length = (env)->GetStringLength(jstr );
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const jchar* jcstr = (env)->GetStringChars(jstr, 0 );
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char* rtn = (char*)malloc( length*2+1 );
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int size = 0;
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size = WideCharToMultiByte( CP_ACP, 0, (LPCWSTR)jcstr, length, rtn,(length*2+1), NULL, NULL );
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if( size <= 0 )
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return NULL;
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(env)->ReleaseStringChars(jstr, jcstr );
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rtn[size] = 0;
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return rtn;
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}
1
//将windows类型转换成jstring类型
2
jstring WindowsTojstring( JNIEnv* env, char* str )
3
{
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jstring rtn = 0;
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int slen = strlen(str);
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unsigned short * buffer = 0;
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if( slen == 0 )
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rtn = (env)->NewStringUTF(str );
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else
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{
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int length = MultiByteToWideChar( CP_ACP, 0, (LPCSTR)str, slen, NULL, 0 );
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buffer = (unsigned short *)malloc( length*2 + 1 );
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if( MultiByteToWideChar( CP_ACP, 0, (LPCSTR)str, slen, (LPWSTR)buffer, length ) >0 )
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rtn = (env)->NewString( (jchar*)buffer, length );
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}
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if( buffer )
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free( buffer );
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return rtn;
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}
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/*JNIEXPORT jstring JNICALL Java_test_cs_web_SWIFTAlianceCASmfTest_strcal
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(JNIEnv *env, jclass obj, jstring jstr1, jstring jstr2)
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{
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jbyteArray bytes = 0;
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jthrowable exc;
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char *pszResult = NULL;
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char *pszSTR1 = NULL;
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char *pszSTR2 = NULL;
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pszSTR1 = jstringTostring(env, jstr1);
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pszSTR2 = jstringTostring(env, jstr2);
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int nlen = sizeof(char)*(strlen(pszSTR1)+strlen(pszSTR2));
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pszResult = (char*)malloc(nlen);
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strcpy(pszResult, pszSTR1);
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strcat(pszResult, pszSTR2);
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jstring jstrRe = stoJstring(env, pszResult);
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free(pszSTR1);
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free(pszSTR2);
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free(pszResult);
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return(jstrRe);
}
1
//从传进来的对象中取出byte[]
2
jfieldID byteData = (env)->GetFieldID(clazz,"bData","[B");
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jbyteArray pDataIn = (jbyteArray) (env)->GetObjectField(objDataIn, byteData);
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jsize theArrayLeng = env->GetArrayLength(pDataIn);
1
//byte[]转为BYTE[]
2
jbyte * arrayBody = env->GetByteArrayElements(pDataIn,0);
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BYTE * jDataIn = (BYTE *)arrayBody;
1
//将BYTE数组转为jarray
2
jbyte* byte = (jbyte*)jDataOut;
3
jbyteArray jarray = env->NewByteArray(theArrayLeng);
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env->SetByteArrayRegion(jarray, 0, theArrayLeng, byte);
1
//给每一个实例的变量付值
2
(env)->SetObjectField(objDataIn,byteData,jarray);
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(env)->SetIntField(objDataIn,pDataInLen,jDataInLen);
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(env)->ReleaseByteArrayElements(pDataIn, arrayBody, 0);