Problem calling a Java Method from C++

Question

hi everyone,
i'm using JNI and i'm trying to call a Java method from C++, this is the code:
SocketC.java
public class SocketC
private native void conectaServidor();
private void recibeBuffer()
System.out.println("HELLO!!!");
public static void main(String args[])
SocketC SC = new SocketC();
SC.conectaServidor();
static {
System.loadLibrary("Server_TCP");
Server_TCP.cpp
char* recibirSock()
     int _flag = 1;
     while(_flag != 0)
          memset(buffer,0,sizeof(buffer));//Et la, celle pour recevoir
          recv(sock,buffer,sizeof(buffer),0);
          printf(" Mensaje del cliente: %s\n",buffer);
          _flag = strcmp(buffer,"salir");
     }//fin while
     return buffer;
void enviarSock()
     int _flag = 1;
     getchar();
     while(_flag != 0)
          memset(buffer,0,sizeof(buffer));//procedimiento para enviar
          printf("\n Escriba: ");
          gets(buffer);
     //     err=scanf("%s",buffer);
          send(sock,buffer,sizeof(buffer),0);
          _flag = strcmp(buffer,"salir");
     }//fin while
}//fin enviarSock
DWORD servicio(LPVOID lpvoid)//
     char *buf;
     printf("\n Cliente aceptado!!!!!\n");
     buf=recibirSock();
     return 0;
JNIEXPORT void JNICALL Java_SocketC_conectaServidor(JNIEnv *env, jobject obj)
//void main()
/*this is the problem i'm calling the method recibeBuffer*/
     jclass cls = env->GetObjectClass(obj);
     jmethodID mmid = env->GetMethodID(cls, "recibeBuffer", "(V)V");
     if (mmid == 0)
          return;
     env->CallVoidMethod(obj, mmid); //llama a Java
     WSAStartup(MAKEWORD(2,0),&wsa);//MAKEWORD dit qu'on utilise la version 2 de winsock
     printf("TCP conexion Sockets\n\n");
     //estimez vous heureux que je foute pas de copyright ;)
     system("TITLE TCP Conexion Sockets (Version server)");
     //fo avouer que c'est plus joli
     int port;
     printf("Port : ");//On demande juste le port, pas besoin d'ip on est sur un server
     scanf("%i",&port);
     sinserv.sin_family=AF_INET;     //Je ne connais pas d'autres familles
     sinserv.sin_addr.s_addr=INADDR_ANY;//Pas besoin d'ip pour le server
     sinserv.sin_port=htons(port);
     server=socket(AF_INET,SOCK_STREAM,0);//On construit le server
     //SOCK_STREAM pour le TCP
     bind(server,(SOCKADDR*)&sinserv,sizeof(sinserv));
     //On lie les parametres du socket avec le socket lui meme
     listen(server,SOMAXCONN);//On se met � �couter avec server, 0 pour n'accepter qu'une seule connection
     printf(" Servidor conectado.");
     while(1)
          sinsize=sizeof(sin);
          if((sock=accept(server,(SOCKADDR*)&sin,&sinsize))!=INVALID_SOCKET)
          {//accept : acepta cualquier conexion
               if (hReadThread = CreateThread (NULL, 0, (LPTHREAD_START_ROUTINE)
               servicio, 0, 0, &dwThreadID))
                    printf("\nHOLA!");
                    GetExitCodeThread(hReadThread,&dwExitCode);
                    CloseHandle (hReadThread);
               else
                    // Could not create the read thread.
                    printf("No se pudo crear");
                    exit(0);
when i'm running the proyect i get this error:
C:\POT Files\UCAB\tesis\esmart\french>java SocketC
Exception in thread "main" java.lang.NoSuchMethodError: recibeBuffer
at SocketC.conectaServidor(Native Method)
at SocketC.main(SocketC.java:16)
i don't know why this is happening i got declare the method recibeBuffer in my SocketC.java class, but doesn;t work can anyone help me?
PD: sorry for my bad english i'm from Venezuela

Answer 1

Next time please paste your code between [code] tags with the code button just above the edit message area.
To answer your question, you wrote the wrong method signature. It should be:jmethodID mmid = env->GetMethodID(cls, "recibeBuffer", "()V");Regards