public void writeNfcV(Tag tag, int oldValue, int newValue) throws Exception {
int currentValue = readNfcV(tag);
if (((oldValue != -1) && (oldValue != 0) && (currentValue != oldValue))
|| (((oldValue == -1) || (oldValue == 0)) && ((currentValue != 0) && currentValue != -1))) {
callbackContext.error(FALSE_TAG);
return;
}
byte[] data = ByteBuffer.allocate(4).putInt(newValue).array();
if (tag == null) {
callbackContext.error("NULL");
return;
}
NfcV nfcv = NfcV.get(tag);
nfcv.connect();
byte[] request = new byte[7];
request[0] = 0x00; // flag
request[1] = 0x21; // command: WRITE ONE BLOCK
request[2] = (byte) block; // IMMER im gleichen Block speichern
request[3] = (byte) data[0];
request[4] = (byte) data[1];
request[5] = (byte) data[2];
request[6] = (byte) data[3];
try {
byte[] response = nfcv.transceive(request);
if (response[0] != (byte) 0x00) {
callbackContext.error("Error code: " + response[1]);
}
} catch (IOException e) {
if (e.getMessage().equals("Tag was lost.")) {
// continue, because of Tag bug
} else {
callbackContext.error("Couldn't write on Tag");
throw e;
}
}
nfcv.close();
int result = readNfcV(tag);
PluginResult pluginResult = new PluginResult(PluginResult.Status.OK, result);
callbackContext.sendPluginResult(pluginResult);
}
public int readNfcV(Tag tag) throws Exception {
if (tag == null) {
callbackContext.error("NULL");
}
byte[] response = new byte[4];
NfcV nfcv = NfcV.get(tag);
if (nfcv != null) {
try {
nfcv.connect();
byte[] request =
new byte[] {
(byte) 0x00, // flag
(byte) 0x20, // command: READ ONE BLOCK
(byte) block // IMMER im gleichen Block
};
response = nfcv.transceive(request);
} catch (IOException e) {
callbackContext.error(nfcv.toString());
} finally {
try {
nfcv.close();
} catch (IOException e) {
}
}
}
// 1. Byte: Block locking status
byte[] value = new byte[] {response[1], response[2], response[3], response[4]};
return ByteBuffer.wrap(value).order(java.nio.ByteOrder.BIG_ENDIAN).getInt();
}