Trying to pass the following from Java code to a shared C library .so. I am very new to JNA if someone would point me i the right direction i would be very grateful.
The error i am getting is: java.lang.Error: Structure.getFieldOrder() on class com.dataTypes.TCIMUEvent does not provide enough names [0] ([]) to match declared fields [11] ([accel, accelValid, gyro, gyroValid, mag, magValid, pressure, pressureValid, temperature, temperatureValid, time])
The two relevant Objects/Structure:
public class Motion extends Structure {
public TCIMUEvent tcimuEvent;
public int Status;
public double userHeadingDeg;
public float rotationMode;
public Motion() {
}
public TCIMUEvent getTcimuEvent() {
return tcimuEvent;
}
public Motion(TCIMUEvent tcimuEvent, int status, double userHeadingDeg, float rotationMode) {
this.tcimuEvent = tcimuEvent;
Status = status;
this.userHeadingDeg = userHeadingDeg;
this.rotationMode = rotationMode;
}
public class TCIMUEvent extends Structure {
public double time;
public float[] accel;
public boolean accelValid;
public float[] mag;
public boolean magValid;
public float[] gyro;
public boolean gyroValid;
public float pressure;
public boolean pressureValid;
public float temperature;
public boolean temperatureValid;
public TCIMUEvent(double time, float[] accel, boolean accelValid, float[] mag, boolean magValid, float[] gyro, boolean gyroValid, float pressure, boolean pressureValid, float temperature, boolean temperatureValid) {
this.time = time;
this.accel = accel;
this.accelValid = accelValid;
this.mag = mag;
this.magValid = magValid;
this.gyro = gyro;
this.gyroValid = gyroValid;
this.pressure = pressure;
this.pressureValid = pressureValid;
this.temperature = temperature;
this.temperatureValid = temperatureValid;
}
The C sample stuct:
typedef struct {
double time;
double accel[3];
bool accelValid;
double mag[3];
bool magValid;
double gyro[3];
bool gyroValid;
double pressure;
bool pressureValid;
double temperature;
bool temperatureValid;
} T_imuDataSample_t;
The C file handling the data:
void HandleImuEvent(T_imuDataSample_t *imuDataSample, int *status,
double *userHeadingDeg, StrapdownStreaming_RotationMode *currentRotateMode)
{
This is where the data gets handed from Java to C:
HandleImuEvent(motion.getTcimuEvent(), motion.getStatus(), motions.getUserHeadingDeg(), motions.getRotationMode());
The full trace on the error is:
java.lang.Error: Structure.getFieldOrder() on class com.dataTypes.TCIMUEvent does not provide enough names [0] ([]) to match declared fields [11] ([accel, accelValid, gyro, gyroValid, mag, magValid, pressure, pressureValid, temperature, temperatureValid, time])
at com.sun.jna.Structure.getFields(Structure.java:1077)
at com.sun.jna.Structure.deriveLayout(Structure.java:1232)
at com.sun.jna.Structure.calculateSize(Structure.java:1159)
at com.sun.jna.Structure.allocateMemory(Structure.java:401)
at com.sun.jna.Structure.ensureAllocated(Structure.java:377)
at com.sun.jna.Structure.ensureAllocated(Structure.java:367)
at com.sun.jna.Structure.size(Structure.java:434)
at com.sun.jna.Structure.size(Structure.java:1137)
at com.sun.jna.Native.getNativeSize(Native.java:1354)
at com.sun.jna.Structure.getNativeSize(Structure.java:2253)
at com.sun.jna.Structure.getNativeSize(Structure.java:2243)
at com.sun.jna.Structure.validateField(Structure.java:1209)
at com.sun.jna.Structure.validateFields(Structure.java:1222)
at com.sun.jna.Structure.<init>(Structure.java:200)
at com.sun.jna.Structure.<init>(Structure.java:193)
at com.sun.jna.Structure.<init>(Structure.java:180)
at com.sun.jna.Structure.<init>(Structure.java:172)
at com.dataTypes.Motion.<init>(Motion.java:17)
I have a feeling i am being a little naive regarding what JNA does so the issue will be my understanding of how i need to pass the data, so general advice on this specific implementation would certainly help me to understand what steps are required to use JNA. I have looked at a lot of the Tutorials out there and am currently looking through other answers on here. If you need any more information or context please just give me a shout.
