https://openjdk.java.net/ 
/*
 * Copyright (c) 2005, 2006, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
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 */

package javax.smartcardio;

import java.util.Arrays;

import java.nio.ByteBuffer;


A command APDU following the structure defined in ISO/IEC 7816-4.
It consists of a four byte header and a conditional body of variable length.
This class does not attempt to verify that the APDU encodes a semantically
valid command.

Note that when the expected length of the response APDU is specified in the constructors, the actual length (Ne) must be specified, not its encoded form (Le). Similarly, getNe returns the actual value Ne. In other words, a value of 0 means "no data in the response APDU" rather than "maximum length." 
This class supports both the short and extended forms of length
encoding for Ne and Nc. However, note that not all terminals and Smart Cards
are capable of accepting APDUs that use the extended form.

For the header bytes CLA, INS, P1, and P2 the Java type int
is used to represent the 8 bit unsigned values. In the constructors, only
the 8 lowest bits of the int value specified by the application
are significant. The accessor methods always return the byte as an unsigned
value between 0 and 255.

Instances of this class are immutable. Where data is passed in or out
via byte arrays, defensive cloning is performed.

Author: Andreas Sterbenz,  JSR 268 Expert Group
See Also:
Since:  1.6
/**
 * A command APDU following the structure defined in ISO/IEC 7816-4.
 * It consists of a four byte header and a conditional body of variable length.
 * This class does not attempt to verify that the APDU encodes a semantically
 * valid command.
 *
 * <p>Note that when the expected length of the response APDU is specified
 * in the {@linkplain #CommandAPDU(int,int,int,int,int) constructors},
 * the actual length (Ne) must be specified, not its
 * encoded form (Le). Similarly, {@linkplain #getNe} returns the actual
 * value Ne. In other words, a value of 0 means "no data in the response APDU"
 * rather than "maximum length."
 *
 * <p>This class supports both the short and extended forms of length
 * encoding for Ne and Nc. However, note that not all terminals and Smart Cards
 * are capable of accepting APDUs that use the extended form.
 *
 * <p>For the header bytes CLA, INS, P1, and P2 the Java type <code>int</code>
 * is used to represent the 8 bit unsigned values. In the constructors, only
 * the 8 lowest bits of the <code>int</code> value specified by the application
 * are significant. The accessor methods always return the byte as an unsigned
 * value between 0 and 255.
 *
 * <p>Instances of this class are immutable. Where data is passed in or out
 * via byte arrays, defensive cloning is performed.
 *
 * @see ResponseAPDU
 * @see CardChannel#transmit CardChannel.transmit
 *
 * @since   1.6
 * @author  Andreas Sterbenz
 * @author  JSR 268 Expert Group
 */
public final class CommandAPDU implements java.io.Serializable {

    private static final long serialVersionUID = 398698301286670877L;

    private static final int MAX_APDU_SIZE = 65544;

    
@serial
/** @serial */
    private byte[] apdu;

    // value of nc
    private transient int nc;

    // value of ne
    private transient int ne;

    // index of start of data within the apdu array
    private transient int dataOffset;

    
Constructs a CommandAPDU from a byte array containing the complete
APDU contents (header and body).

Note that the apdu bytes are copied to protect against
subsequent modification.

Params:
  • apdu – the complete command APDU
Throws:
/**
     * Constructs a CommandAPDU from a byte array containing the complete
     * APDU contents (header and body).
     *
     * <p>Note that the apdu bytes are copied to protect against
     * subsequent modification.
     *
     * @param apdu the complete command APDU
     *
     * @throws NullPointerException if apdu is null
     * @throws IllegalArgumentException if apdu does not contain a valid
     *   command APDU
     */
    public CommandAPDU(byte[] apdu) {
        this.apdu = apdu.clone();
        parse();
    }

    
Constructs a CommandAPDU from a byte array containing the complete
APDU contents (header and body). The APDU starts at the index
apduOffset in the byte array and is apduLength
bytes long.

Note that the apdu bytes are copied to protect against
subsequent modification.

Params:
  • apdu – the complete command APDU
  • apduOffset – the offset in the byte array at which the apdu
  data begins
  • apduLength – the length of the APDU
Throws:
/**
     * Constructs a CommandAPDU from a byte array containing the complete
     * APDU contents (header and body). The APDU starts at the index
     * <code>apduOffset</code> in the byte array and is <code>apduLength</code>
     * bytes long.
     *
     * <p>Note that the apdu bytes are copied to protect against
     * subsequent modification.
     *
     * @param apdu the complete command APDU
     * @param apduOffset the offset in the byte array at which the apdu
     *   data begins
     * @param apduLength the length of the APDU
     *
     * @throws NullPointerException if apdu is null
     * @throws IllegalArgumentException if apduOffset or apduLength are
     *   negative or if apduOffset + apduLength are greater than apdu.length,
     *   or if the specified bytes are not a valid APDU
     */
    public CommandAPDU(byte[] apdu, int apduOffset, int apduLength) {
        checkArrayBounds(apdu, apduOffset, apduLength);
        this.apdu = new byte[apduLength];
        System.arraycopy(apdu, apduOffset, this.apdu, 0, apduLength);
        parse();
    }

    private void checkArrayBounds(byte[] b, int ofs, int len) {
        if ((ofs < 0) || (len < 0)) {
            throw new IllegalArgumentException
                ("Offset and length must not be negative");
        }
        if (b == null) {
            if ((ofs != 0) && (len != 0)) {
                throw new IllegalArgumentException
                    ("offset and length must be 0 if array is null");
            }
        } else {
            if (ofs > b.length - len) {
                throw new IllegalArgumentException
                    ("Offset plus length exceed array size");
            }
        }
    }

    
Creates a CommandAPDU from the ByteBuffer containing the complete APDU
contents (header and body).
The buffer's position must be set to the start of the APDU,
its limit to the end of the APDU. Upon return, the buffer's
position is equal to its limit; its limit remains unchanged.

Note that the data in the ByteBuffer is copied to protect against
subsequent modification.

Params:
  • apdu – the ByteBuffer containing the complete APDU
Throws:
/**
     * Creates a CommandAPDU from the ByteBuffer containing the complete APDU
     * contents (header and body).
     * The buffer's <code>position</code> must be set to the start of the APDU,
     * its <code>limit</code> to the end of the APDU. Upon return, the buffer's
     * <code>position</code> is equal to its limit; its limit remains unchanged.
     *
     * <p>Note that the data in the ByteBuffer is copied to protect against
     * subsequent modification.
     *
     * @param apdu the ByteBuffer containing the complete APDU
     *
     * @throws NullPointerException if apdu is null
     * @throws IllegalArgumentException if apdu does not contain a valid
     *   command APDU
     */
    public CommandAPDU(ByteBuffer apdu) {
        this.apdu = new byte[apdu.remaining()];
        apdu.get(this.apdu);
        parse();
    }

    
Constructs a CommandAPDU from the four header bytes. This is case 1
in ISO 7816, no command body.

Params:
  • cla – the class byte CLA
  • ins – the instruction byte INS
  • p1 – the parameter byte P1
  • p2 – the parameter byte P2
/**
     * Constructs a CommandAPDU from the four header bytes. This is case 1
     * in ISO 7816, no command body.
     *
     * @param cla the class byte CLA
     * @param ins the instruction byte INS
     * @param p1 the parameter byte P1
     * @param p2 the parameter byte P2
     */
    public CommandAPDU(int cla, int ins, int p1, int p2) {
        this(cla, ins, p1, p2, null, 0, 0, 0);
    }

    
Constructs a CommandAPDU from the four header bytes and the expected
response data length. This is case 2 in ISO 7816, empty command data
field with Ne specified. If Ne is 0, the APDU is encoded as ISO 7816
case 1.

Params:
  • cla – the class byte CLA
  • ins – the instruction byte INS
  • p1 – the parameter byte P1
  • p2 – the parameter byte P2
  • ne – the maximum number of expected data bytes in a response APDU
Throws:
/**
     * Constructs a CommandAPDU from the four header bytes and the expected
     * response data length. This is case 2 in ISO 7816, empty command data
     * field with Ne specified. If Ne is 0, the APDU is encoded as ISO 7816
     * case 1.
     *
     * @param cla the class byte CLA
     * @param ins the instruction byte INS
     * @param p1 the parameter byte P1
     * @param p2 the parameter byte P2
     * @param ne the maximum number of expected data bytes in a response APDU
     *
     * @throws IllegalArgumentException if ne is negative or greater than
     *   65536
     */
    public CommandAPDU(int cla, int ins, int p1, int p2, int ne) {
        this(cla, ins, p1, p2, null, 0, 0, ne);
    }

    
Constructs a CommandAPDU from the four header bytes and command data.
This is case 3 in ISO 7816, command data present and Ne absent. The
value Nc is taken as data.length. If data is null or
its length is 0, the APDU is encoded as ISO 7816 case 1.

Note that the data bytes are copied to protect against
subsequent modification.

Params:
  • cla – the class byte CLA
  • ins – the instruction byte INS
  • p1 – the parameter byte P1
  • p2 – the parameter byte P2
  • data – the byte array containing the data bytes of the command body
Throws:
/**
     * Constructs a CommandAPDU from the four header bytes and command data.
     * This is case 3 in ISO 7816, command data present and Ne absent. The
     * value Nc is taken as data.length. If <code>data</code> is null or
     * its length is 0, the APDU is encoded as ISO 7816 case 1.
     *
     * <p>Note that the data bytes are copied to protect against
     * subsequent modification.
     *
     * @param cla the class byte CLA
     * @param ins the instruction byte INS
     * @param p1 the parameter byte P1
     * @param p2 the parameter byte P2
     * @param data the byte array containing the data bytes of the command body
     *
     * @throws IllegalArgumentException if data.length is greater than 65535
     */
    public CommandAPDU(int cla, int ins, int p1, int p2, byte[] data) {
        this(cla, ins, p1, p2, data, 0, arrayLength(data), 0);
    }

    
Constructs a CommandAPDU from the four header bytes and command data.
This is case 3 in ISO 7816, command data present and Ne absent. The
value Nc is taken as dataLength. If dataLength
is 0, the APDU is encoded as ISO 7816 case 1.

Note that the data bytes are copied to protect against
subsequent modification.

Params:
  • cla – the class byte CLA
  • ins – the instruction byte INS
  • p1 – the parameter byte P1
  • p2 – the parameter byte P2
  • data – the byte array containing the data bytes of the command body
  • dataOffset – the offset in the byte array at which the data
  bytes of the command body begin
  • dataLength – the number of the data bytes in the command body
Throws:
  • NullPointerException – if data is null and dataLength is not 0
  • IllegalArgumentException – if dataOffset or dataLength are
  negative or if dataOffset + dataLength are greater than data.length
  or if dataLength is greater than 65535
/**
     * Constructs a CommandAPDU from the four header bytes and command data.
     * This is case 3 in ISO 7816, command data present and Ne absent. The
     * value Nc is taken as dataLength. If <code>dataLength</code>
     * is 0, the APDU is encoded as ISO 7816 case 1.
     *
     * <p>Note that the data bytes are copied to protect against
     * subsequent modification.
     *
     * @param cla the class byte CLA
     * @param ins the instruction byte INS
     * @param p1 the parameter byte P1
     * @param p2 the parameter byte P2
     * @param data the byte array containing the data bytes of the command body
     * @param dataOffset the offset in the byte array at which the data
     *   bytes of the command body begin
     * @param dataLength the number of the data bytes in the command body
     *
     * @throws NullPointerException if data is null and dataLength is not 0
     * @throws IllegalArgumentException if dataOffset or dataLength are
     *   negative or if dataOffset + dataLength are greater than data.length
     *   or if dataLength is greater than 65535
     */
    public CommandAPDU(int cla, int ins, int p1, int p2, byte[] data,
            int dataOffset, int dataLength) {
        this(cla, ins, p1, p2, data, dataOffset, dataLength, 0);
    }

    
Constructs a CommandAPDU from the four header bytes, command data,
and expected response data length. This is case 4 in ISO 7816,
command data and Ne present. The value Nc is taken as data.length
if data is non-null and as 0 otherwise. If Ne or Nc
are zero, the APDU is encoded as case 1, 2, or 3 per ISO 7816.

Note that the data bytes are copied to protect against
subsequent modification.

Params:
  • cla – the class byte CLA
  • ins – the instruction byte INS
  • p1 – the parameter byte P1
  • p2 – the parameter byte P2
  • data – the byte array containing the data bytes of the command body
  • ne – the maximum number of expected data bytes in a response APDU
Throws:
/**
     * Constructs a CommandAPDU from the four header bytes, command data,
     * and expected response data length. This is case 4 in ISO 7816,
     * command data and Ne present. The value Nc is taken as data.length
     * if <code>data</code> is non-null and as 0 otherwise. If Ne or Nc
     * are zero, the APDU is encoded as case 1, 2, or 3 per ISO 7816.
     *
     * <p>Note that the data bytes are copied to protect against
     * subsequent modification.
     *
     * @param cla the class byte CLA
     * @param ins the instruction byte INS
     * @param p1 the parameter byte P1
     * @param p2 the parameter byte P2
     * @param data the byte array containing the data bytes of the command body
     * @param ne the maximum number of expected data bytes in a response APDU
     *
     * @throws IllegalArgumentException if data.length is greater than 65535
     *   or if ne is negative or greater than 65536
     */
    public CommandAPDU(int cla, int ins, int p1, int p2, byte[] data, int ne) {
        this(cla, ins, p1, p2, data, 0, arrayLength(data), ne);
    }

    private static int arrayLength(byte[] b) {
        return (b != null) ? b.length : 0;
    }

    
Command APDU encoding options:
case 1:  |CLA|INS|P1 |P2 |                                 len = 4
case 2s: |CLA|INS|P1 |P2 |LE |                             len = 5
case 3s: |CLA|INS|P1 |P2 |LC |...BODY...|                  len = 6..260
case 4s: |CLA|INS|P1 |P2 |LC |...BODY...|LE |              len = 7..261
case 2e: |CLA|INS|P1 |P2 |00 |LE1|LE2|                     len = 7
case 3e: |CLA|INS|P1 |P2 |00 |LC1|LC2|...BODY...|          len = 8..65542
case 4e: |CLA|INS|P1 |P2 |00 |LC1|LC2|...BODY...|LE1|LE2|  len =10..65544
LE, LE1, LE2 may be 0x00.
LC must not be 0x00 and LC1|LC2 must not be 0x00|0x00

/**
     * Command APDU encoding options:
     *
     * case 1:  |CLA|INS|P1 |P2 |                                 len = 4
     * case 2s: |CLA|INS|P1 |P2 |LE |                             len = 5
     * case 3s: |CLA|INS|P1 |P2 |LC |...BODY...|                  len = 6..260
     * case 4s: |CLA|INS|P1 |P2 |LC |...BODY...|LE |              len = 7..261
     * case 2e: |CLA|INS|P1 |P2 |00 |LE1|LE2|                     len = 7
     * case 3e: |CLA|INS|P1 |P2 |00 |LC1|LC2|...BODY...|          len = 8..65542
     * case 4e: |CLA|INS|P1 |P2 |00 |LC1|LC2|...BODY...|LE1|LE2|  len =10..65544
     *
     * LE, LE1, LE2 may be 0x00.
     * LC must not be 0x00 and LC1|LC2 must not be 0x00|0x00
     */
    private void parse() {
        if (apdu.length < 4) {
            throw new IllegalArgumentException("apdu must be at least 4 bytes long");
        }
        if (apdu.length == 4) {
            // case 1
            return;
        }
        int l1 = apdu[4] & 0xff;
        if (apdu.length == 5) {
            // case 2s
            this.ne = (l1 == 0) ? 256 : l1;
            return;
        }
        if (l1 != 0) {
            if (apdu.length == 4 + 1 + l1) {
                // case 3s
                this.nc = l1;
                this.dataOffset = 5;
                return;
            } else if (apdu.length == 4 + 2 + l1) {
                // case 4s
                this.nc = l1;
                this.dataOffset = 5;
                int l2 = apdu[apdu.length - 1] & 0xff;
                this.ne = (l2 == 0) ? 256 : l2;
                return;
            } else {
                throw new IllegalArgumentException
                    ("Invalid APDU: length=" + apdu.length + ", b1=" + l1);
            }
        }
        if (apdu.length < 7) {
            throw new IllegalArgumentException
                ("Invalid APDU: length=" + apdu.length + ", b1=" + l1);
        }
        int l2 = ((apdu[5] & 0xff) << 8) | (apdu[6] & 0xff);
        if (apdu.length == 7) {
            // case 2e
            this.ne = (l2 == 0) ? 65536 : l2;
            return;
        }
        if (l2 == 0) {
            throw new IllegalArgumentException("Invalid APDU: length="
                    + apdu.length + ", b1=" + l1 + ", b2||b3=" + l2);
        }
        if (apdu.length == 4 + 3 + l2) {
            // case 3e
            this.nc = l2;
            this.dataOffset = 7;
            return;
        } else if (apdu.length == 4 + 5 + l2) {
            // case 4e
            this.nc = l2;
            this.dataOffset = 7;
            int leOfs = apdu.length - 2;
            int l3 = ((apdu[leOfs] & 0xff) << 8) | (apdu[leOfs + 1] & 0xff);
            this.ne = (l3 == 0) ? 65536 : l3;
        } else {
            throw new IllegalArgumentException("Invalid APDU: length="
                    + apdu.length + ", b1=" + l1 + ", b2||b3=" + l2);
        }
    }

    
Constructs a CommandAPDU from the four header bytes, command data,
and expected response data length. This is case 4 in ISO 7816,
command data and Le present. The value Nc is taken as
dataLength.
If Ne or Nc
are zero, the APDU is encoded as case 1, 2, or 3 per ISO 7816.

Note that the data bytes are copied to protect against
subsequent modification.

Params:
  • cla – the class byte CLA
  • ins – the instruction byte INS
  • p1 – the parameter byte P1
  • p2 – the parameter byte P2
  • data – the byte array containing the data bytes of the command body
  • dataOffset – the offset in the byte array at which the data
  bytes of the command body begin
  • dataLength – the number of the data bytes in the command body
  • ne – the maximum number of expected data bytes in a response APDU
Throws:
  • NullPointerException – if data is null and dataLength is not 0
  • IllegalArgumentException – if dataOffset or dataLength are
  negative or if dataOffset + dataLength are greater than data.length,
  or if ne is negative or greater than 65536,
  or if dataLength is greater than 65535
/**
     * Constructs a CommandAPDU from the four header bytes, command data,
     * and expected response data length. This is case 4 in ISO 7816,
     * command data and Le present. The value Nc is taken as
     * <code>dataLength</code>.
     * If Ne or Nc
     * are zero, the APDU is encoded as case 1, 2, or 3 per ISO 7816.
     *
     * <p>Note that the data bytes are copied to protect against
     * subsequent modification.
     *
     * @param cla the class byte CLA
     * @param ins the instruction byte INS
     * @param p1 the parameter byte P1
     * @param p2 the parameter byte P2
     * @param data the byte array containing the data bytes of the command body
     * @param dataOffset the offset in the byte array at which the data
     *   bytes of the command body begin
     * @param dataLength the number of the data bytes in the command body
     * @param ne the maximum number of expected data bytes in a response APDU
     *
     * @throws NullPointerException if data is null and dataLength is not 0
     * @throws IllegalArgumentException if dataOffset or dataLength are
     *   negative or if dataOffset + dataLength are greater than data.length,
     *   or if ne is negative or greater than 65536,
     *   or if dataLength is greater than 65535
     */
    public CommandAPDU(int cla, int ins, int p1, int p2, byte[] data,
            int dataOffset, int dataLength, int ne) {
        checkArrayBounds(data, dataOffset, dataLength);
        if (dataLength > 65535) {
            throw new IllegalArgumentException("dataLength is too large");
        }
        if (ne < 0) {
            throw new IllegalArgumentException("ne must not be negative");
        }
        if (ne > 65536) {
            throw new IllegalArgumentException("ne is too large");
        }
        this.ne = ne;
        this.nc = dataLength;
        if (dataLength == 0) {
            if (ne == 0) {
                // case 1
                this.apdu = new byte[4];
                setHeader(cla, ins, p1, p2);
            } else {
                // case 2s or 2e
                if (ne <= 256) {
                    // case 2s
                    // 256 is encoded as 0x00
                    byte len = (ne != 256) ? (byte)ne : 0;
                    this.apdu = new byte[5];
                    setHeader(cla, ins, p1, p2);
                    this.apdu[4] = len;
                } else {
                    // case 2e
                    byte l1, l2;
                    // 65536 is encoded as 0x00 0x00
                    if (ne == 65536) {
                        l1 = 0;
                        l2 = 0;
                    } else {
                        l1 = (byte)(ne >> 8);
                        l2 = (byte)ne;
                    }
                    this.apdu = new byte[7];
                    setHeader(cla, ins, p1, p2);
                    this.apdu[5] = l1;
                    this.apdu[6] = l2;
                }
            }
        } else {
            if (ne == 0) {
                // case 3s or 3e
                if (dataLength <= 255) {
                    // case 3s
                    apdu = new byte[4 + 1 + dataLength];
                    setHeader(cla, ins, p1, p2);
                    apdu[4] = (byte)dataLength;
                    this.dataOffset = 5;
                    System.arraycopy(data, dataOffset, apdu, 5, dataLength);
                } else {
                    // case 3e
                    apdu = new byte[4 + 3 + dataLength];
                    setHeader(cla, ins, p1, p2);
                    apdu[4] = 0;
                    apdu[5] = (byte)(dataLength >> 8);
                    apdu[6] = (byte)dataLength;
                    this.dataOffset = 7;
                    System.arraycopy(data, dataOffset, apdu, 7, dataLength);
                }
            } else {
                // case 4s or 4e
                if ((dataLength <= 255) && (ne <= 256)) {
                    // case 4s
                    apdu = new byte[4 + 2 + dataLength];
                    setHeader(cla, ins, p1, p2);
                    apdu[4] = (byte)dataLength;
                    this.dataOffset = 5;
                    System.arraycopy(data, dataOffset, apdu, 5, dataLength);
                    apdu[apdu.length - 1] = (ne != 256) ? (byte)ne : 0;
                } else {
                    // case 4e
                    apdu = new byte[4 + 5 + dataLength];
                    setHeader(cla, ins, p1, p2);
                    apdu[4] = 0;
                    apdu[5] = (byte)(dataLength >> 8);
                    apdu[6] = (byte)dataLength;
                    this.dataOffset = 7;
                    System.arraycopy(data, dataOffset, apdu, 7, dataLength);
                    if (ne != 65536) {
                        int leOfs = apdu.length - 2;
                        apdu[leOfs] = (byte)(ne >> 8);
                        apdu[leOfs + 1] = (byte)ne;
                    } // else le == 65536: no need to fill in, encoded as 0
                }
            }
        }
    }

    private void setHeader(int cla, int ins, int p1, int p2) {
        apdu[0] = (byte)cla;
        apdu[1] = (byte)ins;
        apdu[2] = (byte)p1;
        apdu[3] = (byte)p2;
    }

    
Returns the value of the class byte CLA.

Returns:the value of the class byte CLA.
/**
     * Returns the value of the class byte CLA.
     *
     * @return the value of the class byte CLA.
     */
    public int getCLA() {
        return apdu[0] & 0xff;
    }

    
Returns the value of the instruction byte INS.

Returns:the value of the instruction byte INS.
/**
     * Returns the value of the instruction byte INS.
     *
     * @return the value of the instruction byte INS.
     */
    public int getINS() {
        return apdu[1] & 0xff;
    }

    
Returns the value of the parameter byte P1.

Returns:the value of the parameter byte P1.
/**
     * Returns the value of the parameter byte P1.
     *
     * @return the value of the parameter byte P1.
     */
    public int getP1() {
        return apdu[2] & 0xff;
    }

    
Returns the value of the parameter byte P2.

Returns:the value of the parameter byte P2.
/**
     * Returns the value of the parameter byte P2.
     *
     * @return the value of the parameter byte P2.
     */
    public int getP2() {
        return apdu[3] & 0xff;
    }

    
Returns the number of data bytes in the command body (Nc) or 0 if this
APDU has no body. This call is equivalent to
getData().length.

Returns:the number of data bytes in the command body or 0 if this APDU
has no body.
/**
     * Returns the number of data bytes in the command body (Nc) or 0 if this
     * APDU has no body. This call is equivalent to
     * <code>getData().length</code>.
     *
     * @return the number of data bytes in the command body or 0 if this APDU
     * has no body.
     */
    public int getNc() {
        return nc;
    }

    
Returns a copy of the data bytes in the command body. If this APDU as
no body, this method returns a byte array with length zero.

Returns:a copy of the data bytes in the command body or the empty
   byte array if this APDU has no body.
/**
     * Returns a copy of the data bytes in the command body. If this APDU as
     * no body, this method returns a byte array with length zero.
     *
     * @return a copy of the data bytes in the command body or the empty
     *    byte array if this APDU has no body.
     */
    public byte[] getData() {
        byte[] data = new byte[nc];
        System.arraycopy(apdu, dataOffset, data, 0, nc);
        return data;
    }

    
Returns the maximum number of expected data bytes in a response
APDU (Ne).

Returns:the maximum number of expected data bytes in a response APDU.
/**
     * Returns the maximum number of expected data bytes in a response
     * APDU (Ne).
     *
     * @return the maximum number of expected data bytes in a response APDU.
     */
    public int getNe() {
        return ne;
    }

    
Returns a copy of the bytes in this APDU.

Returns:a copy of the bytes in this APDU.
/**
     * Returns a copy of the bytes in this APDU.
     *
     * @return a copy of the bytes in this APDU.
     */
    public byte[] getBytes() {
        return apdu.clone();
    }

    
Returns a string representation of this command APDU.

Returns:a String representation of this command APDU.
/**
     * Returns a string representation of this command APDU.
     *
     * @return a String representation of this command APDU.
     */
    public String toString() {
        return "CommmandAPDU: " + apdu.length + " bytes, nc=" + nc + ", ne=" + ne;
    }

    
Compares the specified object with this command APDU for equality.
Returns true if the given object is also a CommandAPDU and its bytes are
identical to the bytes in this CommandAPDU.

Params:
  • obj – the object to be compared for equality with this command APDU
Returns:true if the specified object is equal to this command APDU
/**
     * Compares the specified object with this command APDU for equality.
     * Returns true if the given object is also a CommandAPDU and its bytes are
     * identical to the bytes in this CommandAPDU.
     *
     * @param obj the object to be compared for equality with this command APDU
     * @return true if the specified object is equal to this command APDU
     */
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj instanceof CommandAPDU == false) {
            return false;
        }
        CommandAPDU other = (CommandAPDU)obj;
        return Arrays.equals(this.apdu, other.apdu);
     }

    
Returns the hash code value for this command APDU.

Returns:the hash code value for this command APDU.
/**
     * Returns the hash code value for this command APDU.
     *
     * @return the hash code value for this command APDU.
     */
    public int hashCode() {
        return Arrays.hashCode(apdu);
    }

    private void readObject(java.io.ObjectInputStream in)
            throws java.io.IOException, ClassNotFoundException {
        apdu = (byte[])in.readUnshared();
        // initialize transient fields
        parse();
    }

}