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package javax.smartcardio;

import java.nio.*;

A logical channel connection to a Smart Card. It is used to exchange APDUs with a Smart Card. A CardChannel object can be obtained by calling the method Card.getBasicChannel or Card.openLogicalChannel.
Author: Andreas Sterbenz, JSR 268 Expert Group
See Also:
Since: 1.6
/** * A logical channel connection to a Smart Card. It is used to exchange APDUs * with a Smart Card. * A CardChannel object can be obtained by calling the method * {@linkplain Card#getBasicChannel} or {@linkplain Card#openLogicalChannel}. * * @see Card * @see CommandAPDU * @see ResponseAPDU * * @since 1.6 * @author Andreas Sterbenz * @author JSR 268 Expert Group */
public abstract class CardChannel {
Constructs a new CardChannel object.

This constructor is called by subclasses only. Application should call the Card.getBasicChannel and Card.openLogicalChannel methods to obtain a CardChannel object.

/** * Constructs a new CardChannel object. * * <p>This constructor is called by subclasses only. Application should * call the {@linkplain Card#getBasicChannel} and * {@linkplain Card#openLogicalChannel} methods to obtain a CardChannel * object. */
protected CardChannel() { // empty }
Returns the Card this channel is associated with.
Returns:the Card this channel is associated with
/** * Returns the Card this channel is associated with. * * @return the Card this channel is associated with */
public abstract Card getCard();
Returns the channel number of this CardChannel. A channel number of 0 indicates the basic logical channel.
Throws:
Returns:the channel number of this CardChannel.
/** * Returns the channel number of this CardChannel. A channel number of * 0 indicates the basic logical channel. * * @return the channel number of this CardChannel. * * @throws IllegalStateException if this channel has been * {@linkplain #close closed} or if the corresponding Card has been * {@linkplain Card#disconnect disconnected}. */
public abstract int getChannelNumber();
Transmits the specified command APDU to the Smart Card and returns the response APDU.

The CLA byte of the command APDU is automatically adjusted to match the channel number of this CardChannel.

Note that this method cannot be used to transmit MANAGE CHANNEL APDUs. Logical channels should be managed using the Card.openLogicalChannel and CardChannel.close() methods.

Implementations should transparently handle artifacts of the transmission protocol. For example, when using the T=0 protocol, the following processing should occur as described in ISO/IEC 7816-4:

  • if the response APDU has an SW1 of 61, the implementation should issue a GET RESPONSE command using SW2 as the Lefield. This process is repeated as long as an SW1 of 61 is received. The response body of these exchanges is concatenated to form the final response body.

  • if the response APDU is 6C XX, the implementation should reissue the command using XX as the Le field.

The ResponseAPDU returned by this method is the result after this processing has been performed.

Params:
  • command – the command APDU
Throws:
Returns:the response APDU received from the card
/** * Transmits the specified command APDU to the Smart Card and returns the * response APDU. * * <p>The CLA byte of the command APDU is automatically adjusted to * match the channel number of this CardChannel. * * <p>Note that this method cannot be used to transmit * <code>MANAGE CHANNEL</code> APDUs. Logical channels should be managed * using the {@linkplain Card#openLogicalChannel} and {@linkplain * CardChannel#close CardChannel.close()} methods. * * <p>Implementations should transparently handle artifacts * of the transmission protocol. * For example, when using the T=0 protocol, the following processing * should occur as described in ISO/IEC 7816-4: * * <ul> * <li><p>if the response APDU has an SW1 of <code>61</code>, the * implementation should issue a <code>GET RESPONSE</code> command * using <code>SW2</code> as the <code>Le</code>field. * This process is repeated as long as an SW1 of <code>61</code> is * received. The response body of these exchanges is concatenated * to form the final response body. * * <li><p>if the response APDU is <code>6C XX</code>, the implementation * should reissue the command using <code>XX</code> as the * <code>Le</code> field. * </ul> * * <p>The ResponseAPDU returned by this method is the result * after this processing has been performed. * * @param command the command APDU * @return the response APDU received from the card * * @throws IllegalStateException if this channel has been * {@linkplain #close closed} or if the corresponding Card has been * {@linkplain Card#disconnect disconnected}. * @throws IllegalArgumentException if the APDU encodes a * <code>MANAGE CHANNEL</code> command * @throws NullPointerException if command is null * @throws CardException if the card operation failed */
public abstract ResponseAPDU transmit(CommandAPDU command) throws CardException;
Transmits the command APDU stored in the command ByteBuffer and receives the response APDU in the response ByteBuffer.

The command buffer must contain valid command APDU data starting at command.position() and the APDU must be command.remaining() bytes long. Upon return, the command buffer's position will be equal to its limit; its limit will not have changed. The output buffer will have received the response APDU bytes. Its position will have advanced by the number of bytes received, which is also the return value of this method.

The CLA byte of the command APDU is automatically adjusted to match the channel number of this CardChannel.

Note that this method cannot be used to transmit MANAGE CHANNEL APDUs. Logical channels should be managed using the Card.openLogicalChannel and CardChannel.close() methods.

See transmit() for a discussion of the handling of response APDUs with the SW1 values 61 or 6C.

Params:
  • command – the buffer containing the command APDU
  • response – the buffer that shall receive the response APDU from the card
Throws:
Returns:the length of the received response APDU
/** * Transmits the command APDU stored in the command ByteBuffer and receives * the response APDU in the response ByteBuffer. * * <p>The command buffer must contain valid command APDU data starting * at <code>command.position()</code> and the APDU must be * <code>command.remaining()</code> bytes long. * Upon return, the command buffer's position will be equal * to its limit; its limit will not have changed. The output buffer * will have received the response APDU bytes. Its position will have * advanced by the number of bytes received, which is also the return * value of this method. * * <p>The CLA byte of the command APDU is automatically adjusted to * match the channel number of this CardChannel. * * <p>Note that this method cannot be used to transmit * <code>MANAGE CHANNEL</code> APDUs. Logical channels should be managed * using the {@linkplain Card#openLogicalChannel} and {@linkplain * CardChannel#close CardChannel.close()} methods. * * <p>See {@linkplain #transmit transmit()} for a discussion of the handling * of response APDUs with the SW1 values <code>61</code> or <code>6C</code>. * * @param command the buffer containing the command APDU * @param response the buffer that shall receive the response APDU from * the card * @return the length of the received response APDU * * @throws IllegalStateException if this channel has been * {@linkplain #close closed} or if the corresponding Card has been * {@linkplain Card#disconnect disconnected}. * @throws NullPointerException if command or response is null * @throws ReadOnlyBufferException if the response buffer is read-only * @throws IllegalArgumentException if command and response are the * same object, if <code>response</code> may not have * sufficient space to receive the response APDU * or if the APDU encodes a <code>MANAGE CHANNEL</code> command * @throws CardException if the card operation failed */
public abstract int transmit(ByteBuffer command, ByteBuffer response) throws CardException;
Closes this CardChannel. The logical channel is closed by issuing a MANAGE CHANNEL command that should use the format [xx 70 80 0n] where n is the channel number of this channel and xx is the CLA byte that encodes this logical channel and has all other bits set to 0. After this method returns, calling other methods in this class will raise an IllegalStateException.

Note that the basic logical channel cannot be closed using this method. It can be closed by calling Card.disconnect.

Throws:
/** * Closes this CardChannel. The logical channel is closed by issuing * a <code>MANAGE CHANNEL</code> command that should use the format * <code>[xx 70 80 0n]</code> where <code>n</code> is the channel number * of this channel and <code>xx</code> is the <code>CLA</code> * byte that encodes this logical channel and has all other bits set to 0. * After this method returns, calling other * methods in this class will raise an IllegalStateException. * * <p>Note that the basic logical channel cannot be closed using this * method. It can be closed by calling {@link Card#disconnect}. * * @throws CardException if the card operation failed * @throws IllegalStateException if this CardChannel represents a * connection the basic logical channel */
public abstract void close() throws CardException; }