Card (Java SE 12 & JDK 12 )
Keywords: javax.smartcardio.Card class

Module java.smartcardio
Package javax.smartcardio

## Class Card

- java.lang.Object
- - javax.smartcardio.Card

-     public abstract class Card
      extends Object

  A Smart Card with which a connection has been established. Card objects are obtained by calling `CardTerminal.connect()`.
  Since:
    1.6
  See Also:
    `CardTerminal`

- - ### Constructor Summary

    Constructors
    Modifier | Constructor | Description
    --- | --- | ---
    `protected` | `Card()` | Constructs a new Card object.

  - ### Method Summary

    Modifier and Type | Method | Description
    --- | --- | ---
    `abstract void` | `beginExclusive()` | Requests exclusive access to this card.
    `abstract void` | `disconnect​(boolean reset)` | Disconnects the connection with this card.
    `abstract void` | `endExclusive()` | Releases the exclusive access previously established using `beginExclusive`.
    `abstract ATR` | `getATR()` | Returns the ATR of this card.
    `abstract CardChannel` | `getBasicChannel()` | Returns the CardChannel for the basic logical channel.
    `abstract String` | `getProtocol()` | Returns the protocol in use for this card.
    `abstract CardChannel` | `openLogicalChannel()` | Opens a new logical channel to the card and returns it.
    `abstract byte[]` | `transmitControlCommand​(int controlCode, byte[] command)` | Transmits a control command to the terminal device.

    - ### Methods declared in class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### Card

          protected Card()

      Constructs a new Card object.

      This constructor is called by subclasses only. Application should call the CardTerminal.connect() method to obtain a Card object.

  - ### Method Detail

    - #### getATR

          public abstract ATR getATR()

      Returns the ATR of this card.
      Returns:
        the ATR of this card.

    - #### getProtocol

          public abstract String getProtocol()

      Returns the protocol in use for this card.
      Returns:
        the protocol in use for this card, for example "T=0" or "T=1"

    - #### getBasicChannel

          public abstract CardChannel getBasicChannel()

      Returns the CardChannel for the basic logical channel. The basic logical channel has a channel number of 0.
      Returns:
        the CardChannel for the basic logical channel
      Throws:
        `SecurityException` - if a SecurityManager exists and the caller does not have the required permission
        `IllegalStateException` - if this card object has been disposed of via the disconnect() method

    - #### openLogicalChannel

          public abstract CardChannel openLogicalChannel()
                                                  throws CardException

      Opens a new logical channel to the card and returns it. The channel is opened by issuing a `MANAGE CHANNEL` command that should use the format `[00 70 00 00 01]`.
      Returns:
        the logical channel which has been opened
      Throws:
        `SecurityException` - if a SecurityManager exists and the caller does not have the required permission
        `CardException` - is a new logical channel could not be opened
        `IllegalStateException` - if this card object has been disposed of via the disconnect() method

    - #### beginExclusive

          public abstract void beginExclusive()
                                       throws CardException

      Requests exclusive access to this card.

      Once a thread has invoked `beginExclusive`, only this thread is allowed to communicate with this card until it calls `endExclusive`. Other threads attempting communication will receive a CardException.

      Applications have to ensure that exclusive access is correctly released. This can be achieved by executing the `beginExclusive()` and `endExclusive` calls in a `try ... finally` block.

      Throws:
        `SecurityException` - if a SecurityManager exists and the caller does not have the required permission
        `CardException` - if exclusive access has already been set or if exclusive access could not be established
        `IllegalStateException` - if this card object has been disposed of via the disconnect() method

    - #### endExclusive

          public abstract void endExclusive()
                                     throws CardException

      Releases the exclusive access previously established using `beginExclusive`.
      Throws:
        `SecurityException` - if a SecurityManager exists and the caller does not have the required permission
        `IllegalStateException` - if the active Thread does not currently have exclusive access to this card or if this card object has been disposed of via the disconnect() method
        `CardException` - if the operation failed

    - #### transmitControlCommand

          public abstract byte[] transmitControlCommand​(int controlCode,
                                                        byte[] command)
                                                 throws CardException

      Transmits a control command to the terminal device.

      This can be used to, for example, control terminal functions like a built-in PIN pad or biometrics.

      Parameters:
        `controlCode` - the control code of the command
        `command` - the command data
      Returns:
        the response from the terminal device
      Throws:
        `SecurityException` - if a SecurityManager exists and the caller does not have the required permission
        `NullPointerException` - if command is null
        `CardException` - if the card operation failed
        `IllegalStateException` - if this card object has been disposed of via the disconnect() method

    - #### disconnect

          public abstract void disconnect​(boolean reset)
                                   throws CardException

      Disconnects the connection with this card. After this method returns, calling methods on this object or in CardChannels associated with this object that require interaction with the card will raise an IllegalStateException.
      Parameters:
        `reset` - whether to reset the card after disconnecting.
      Throws:
        `CardException` - if the card operation failed
        `SecurityException` - if a SecurityManager exists and the caller does not have the required permission