Java调用dll 闪退,java 调用DLL 读串口,不久就死了,请帮忙看看什么原因?
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发表于2009-6-1 14:20
java 调用DLL 读串口,不久就死了,请帮忙看看什么原因?
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经过仔细分析问题出这dll这里,但始终找不到解决办法,请大家帮忙看看,谢谢!
dll代码如下:
JNIEXPORT jstring JNICALL Java_getGPS
(JNIEnv * env, jobject obj)
{
char * cIpAddress =compressWideChar((LPCWSTR)L"empty value!");
int baud = 9600;//BaudTbl[1];
int parity = 0;//ParityTbl[1];
int databit = 8;//DataBitTbl[1];
int stopbit = 0;//StopBitTbl[1];
//打开串口
if(m_hComm==INVALID_HANDLE_VALUE)
{
m_hComm=CreateFile(TEXT("COM3:"),GENERIC_READ|GENERIC_WRITE,0,0,OPEN_EXISTING,0,0);
if(m_hComm==INVALID_HANDLE_VALUE )
{
cIpAddress =compressWideChar((LPCWSTR)L"COM3 open error!");
ClosePort();
return WindowsTojstring(env, cIpAddress);
}
GetCommState(m_hComm,&dcb);
dcb.BaudRate=baud;//BaudRate;
dcb.ByteSize=databit;//DataBits;
dcb.Parity=parity;//Parity;
dcb.StopBits=stopbit;//StopBits;
dcb.fParity=FALSE;
dcb.fBinary=TRUE;
dcb.fDtrControl=0;
dcb.fRtsControl=0;
dcb.fOutX=dcb.fInX=dcb.fTXContinueOnXoff=0;
//设置状态参数
SetCommMask(m_hComm,EV_RXCHAR);
SetupComm(m_hComm,16384,16384); //old
//SetupComm(m_hComm,4096,4096); //new my add
if(!SetCommState(m_hComm,&dcb))
{
//AfxMessageBox(_T("无法按当前参数配置端口，请检查参数！"));
cIpAddress =compressWideChar((LPCWSTR)L"setup com3 error!");
PurgeComm(m_hComm,PURGE_TXCLEAR|PURGE_RXCLEAR);
ClosePort();
// bOpen = FALSE;
return WindowsTojstring(env, cIpAddress);
}
//设置超时参数
GetCommTimeouts(m_hComm,&CommTimeOuts);
CommTimeOuts.ReadIntervalTimeout=100;//old
CommTimeOuts.ReadTotalTimeoutMultiplier=1;//old
CommTimeOuts.ReadTotalTimeoutConstant=100;//old
CommTimeOuts.WriteTotalTimeoutMultiplier=0;
CommTimeOuts.WriteTotalTimeoutConstant=0;
if(!SetCommTimeouts(m_hComm,&CommTimeOuts))
{
cIpAddress =compressWideChar((LPCWSTR)L"setup Timeout error!");
PurgeComm(m_hComm,PURGE_TXCLEAR|PURGE_RXCLEAR);
ClosePort();
return WindowsTojstring(env, cIpAddress);
}
PurgeComm(m_hComm,PURGE_TXCLEAR|PURGE_RXCLEAR);
}
//读数据
//下边的代码转化中有出问题
while(m_hComm!=INVALID_HANDLE_VALUE)
{
BOOL fReadState;
DWORD dwLength;//,dwBytesRead;
char* buf=new char[256];//256
int length=256;//256
fReadState=ReadFile(m_hComm,buf,length,&dwLength,NULL);//从串口读数
if(fReadState)
{
cIpAddress = NULL;
cIpAddress = buf;
}
jstring str = WindowsTojstring(env, cIpAddress);//我估计问题出在这里 WindowsTojstring()是用于UNICODE转ANSI delete []buf;
delete buf;
delete cIpAddress;
// ClosePort();
return str;
}
else
{
jstring str = WindowsTojstring(env, cIpAddress);
delete []buf;
delete buf;
delete cIpAddress;
// ClosePort();
return str;
}
}
ClosePort();
return WindowsTojstring(env, cIpAddress);
}
//UNICODE转ANSI
jstring WindowsTojstring( JNIEnv* env, char* str )
{
jstring rtn = 0;
int slen = strlen(str);
wchar_t* buffer = 0;
if( slen == 0 )
rtn = env->NewStringUTF( str ); //UTF ok since empty string
else
{
int length = MultiByteToWideChar( CP_ACP, 0, (LPCSTR)str, slen, NULL, 0 );//old
buffer = (wchar_t*)malloc( length*2 + 1 );//old
if( MultiByteToWideChar( CP_ACP, 0, (LPCSTR)str, slen, (LPWSTR)buffer, length ) >0 )
rtn = env->NewString( (jchar*)buffer, length );
}
if( buffer )
{
free( buffer );
delete buffer;
}
return rtn;
}