I am working on a RFID based attendance monitoring system. I used Mifare 1k Classic as my RFID and ACR122u as my reader. I learned that you can store value to the card using the STORE VALUE BLOCK APDU command and can also be read by using READ BLOCK APDU command. Both commands returns 0x90 SW1 which means it transmitted successfully. My problem is how to get/retrieve the value stored to the VALUE BLOCK after reading it. E.g I Stored a value "15" from block 0x05. Now I try to get the value "15" from block 0x05. I tried this codes here:
CommandAPDU comm1 = new CommandAPDU(new byte[] {(byte) 0xFF,(byte) 0xB1,(byte) 0x00,(byte) 0x05,(byte) 0x04});
ResponseAPDU read1 = channel.transmit(comm1);
It successfully reads the block but it doesn't display the value. i tried using:
System.out.println(read1.getBytes());
System.out.println(read1.getData());
But both display some random outputs like: [B@140fee
Can anyone help me with this? And what is the output means?