=======================Android Java Code=============================

        這裡是片段

 public native int OpenPort(int portnum,int brates);
 public native int ClosePort(int portnum);
 public native int READ(char[] databuffer);


 public char[] buffer=new char[40];

 int i;

    for(i=0;i<40;i++)
      buffer[i]='s'; //初始化


 OpenPort(16,9600); 自己寫的開Port

 while (i<1000)
 {
        READ(buffer);
        i++;
                }

=====================以下為JNI.c code===============================

JNIEXPORT jint JNICALL Java_com_example_ndk_Vehicles_READ(JNIEnv *env, jclass
cls,jcharArray databuffer)
{

        char tmp[40];
        jchar *buffer=(*env)->GetCharArrayElements(env,databuffer,0);
        memset(tmp,0,sizeof(tmp));
        PollComport(16,tmp,40);
        memcpy(buffer,tmp,40);

        (*env)->ReleaseCharArrayElements(env, databuffer, buffer, 0);

        return 0;

}