read mcp 3202 in java with kura for raspberry

Question

I try to read a gaz sensor in java with jdk.dio but I always read 0 on my SPI bus with this code:

import java.nio.ByteBuffer;
import org.slf4j.Logger;    
import jdk.dio.Device;
import jdk.dio.DeviceConfig;
import jdk.dio.DeviceManager;
import jdk.dio.spibus.SPIDevice;
import jdk.dio.spibus.SPIDeviceConfig;

public class SPIDACDemo {
    public static void startApp(Logger sLogger, int spiDeviceId) {
        try {
            SPIDeviceConfig config = new SPIDeviceConfig(0, 1, 300000, 0, DeviceConfig.DEFAULT, Device.BIG_ENDIAN);
            SPIDevice spi = (SPIDevice) DeviceManager.open(config);
            while (true) {
                ByteBuffer rcvMsg = ByteBuffer.wrap(new byte[2]);                   
                int resp = spi.read(rcvMsg);
                System.out.println(resp);
                for (byte b : rcvMsg.array()) {
                    System.out.println(b);
                }
                String message = "Response: " + resp + ", Received: " + new String(rcvMsg.array(),"ASCII");
                System.out.println(message);
                Thread.sleep(1000);
            }
            spi.close();
            System.out.println("Done");
        } catch (Exception ex) {
            System.out.println(ex.getMessage());
            sLogger.error(SPIDACDemo.class.getName() + ", error:" + ex);
        }
    }
}

my connection is OK and I can read value in python but in Java I only read 0...