java.lang.Object
- org.apache.commons.codec.digest.Crc16

All Implemented Interfaces:

java.util.zip.Checksum
```
public final class Crc16
extends java.lang.Object
implements java.util.zip.Checksum
```
CRC-16 checksum implementations you can customize with a table and init value.
Since there are so many CRC-16 variants, we do not pick a default.

For example, to create a create a custom variant of CRC16-MODBUS with an init value of 0x0000, use:
```
 Checksum crc16 = CRC16.builder().setTable(CRC16.getModbusTable()).setInit(0x0000).get();
 
```
Since:

1.20.0

See Also:

Cyclic redundancy check, Catalogue of parametrised CRC algorithms with 16 bits, On-line CRC calculation and free library, crccalc

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class Crc16.Builder
Builds Crc16 instances.

Field Summary

Fields
Modifier and Type	Field	Description
`private static int[]`	`ARC`
`private static int`	`ARC_INIT`
`private static int[]`	`CCITT`
`private static int`	`CCITT_INIT`
`private int`	`crc`	CRC.
`private static int[]`	`DNP`
`private static int`	`DNP_INIT`
`private static int`	`DNP_XOROUT`
`private static int[]`	`IBM_SDLC`
`private static int`	`IBM_SDLC_INIT`
`private static int`	`IBM_SDLC_XOROUT`
`private int`	`init`
`private static int[]`	`MAXIM`
`private static int`	`MAXIM_INIT`
`private static int`	`MAXIM_XOROUT`
`private static int[]`	`MCRF4XX`
`private static int`	`MCRF4XX_INIT`
`private static int[]`	`MODBUS`
`private static int`	`MODBUS_INIT`
`private static int[]`	`NRSC5`
`private static int`	`NRSC5_INIT`
`private int[]`	`table`
`private static int[]`	`USB`
`private static int`	`USB_INIT`
`private static int`	`USB_XOROUT`
`private int`	`xorOut`

Constructor Summary

Constructors
Modifier Constructor Description

private Crc16(Crc16.Builder builder)
Constructs a new instance.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`static Crc16`	`arc()`	Creates a new CRC16-CCITT Checksum.
`static Crc16.Builder`	`builder()`	Creates a new builder.
`static Crc16`	`ccitt()`	Creates a new CRC16-CCITT Checksum.
`static Crc16`	`dnp()`	Creates a new CRC16-DNP Checksum.
`static int[]`	`getArcTable()`	Gets a copy of the CRC16-CCITT table.
`static int[]`	`getCcittTable()`	Gets a copy of the CRC16-CCITT table.
`static int[]`	`getDnpTable()`	Gets a copy of the CRC16-DNP table.
`static int[]`	`getIbmSdlcTable()`	Gets a copy of the CRC16-IBM-SDLC table.
`static int[]`	`getMaximTable()`	Gets a copy of the CRC16-MAXIM table.
`static int[]`	`getMcrf4xxTable()`	Gets a copy of the CRC16-MCRF4XX table.
`static int[]`	`getModbusTable()`	Gets a copy of the CRC16-MODBUS table.
`static int[]`	`getNrsc5Table()`	Gets a copy of the CRC16-NRSC-5 table.
`long`	`getValue()`
`static Crc16`	`ibmSdlc()`	Creates a new CRC16-IBM-SDLC Checksum.
`static Crc16`	`maxim()`	Creates a new instance for CRC16-MAXIM Checksum.
`static Crc16`	`mcrf4xx()`	Creates a new instance for CRC16-MCRF4XX Checksum.
`static Crc16`	`modbus()`	Creates a new instance for CRC16-MODBUS Checksum.
`static Crc16`	`nrsc5()`	Creates a new instance for CRC16-NRSC-5 Checksum.
`void`	`reset()`
`java.lang.String`	`toString()`
`void`	`update(byte[] b, int off, int len)`
`void`	`update(int b)`
`static Crc16`	`usb()`	Creates a new instance for CRC16-USB Checksum.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - ARC
```
private static final int[] ARC
```
  - ARC_INIT
```
private static final int ARC_INIT
```
    See Also:
    
    Constant Field Values
  - CCITT
```
private static final int[] CCITT
```
  - CCITT_INIT
```
private static final int CCITT_INIT
```
    See Also:
    
    Constant Field Values
  - DNP
```
private static final int[] DNP
```
  - DNP_INIT
```
private static final int DNP_INIT
```
    See Also:
    
    Constant Field Values
  - DNP_XOROUT
```
private static final int DNP_XOROUT
```
    See Also:
    
    Constant Field Values
  - IBM_SDLC
```
private static final int[] IBM_SDLC
```
  - IBM_SDLC_INIT
```
private static final int IBM_SDLC_INIT
```
    See Also:
    
    Constant Field Values
  - IBM_SDLC_XOROUT
```
private static final int IBM_SDLC_XOROUT
```
    See Also:
    
    Constant Field Values
  - MAXIM
```
private static final int[] MAXIM
```
  - MAXIM_INIT
```
private static final int MAXIM_INIT
```
    See Also:
    
    Constant Field Values
  - MAXIM_XOROUT
```
private static final int MAXIM_XOROUT
```
    See Also:
    
    Constant Field Values
  - MCRF4XX
```
private static final int[] MCRF4XX
```
  - MCRF4XX_INIT
```
private static final int MCRF4XX_INIT
```
    See Also:
    
    Constant Field Values
  - MODBUS
```
private static final int[] MODBUS
```
  - MODBUS_INIT
```
private static final int MODBUS_INIT
```
    See Also:
    
    Constant Field Values
  - NRSC5
```
private static final int[] NRSC5
```
  - NRSC5_INIT
```
private static final int NRSC5_INIT
```
    See Also:
    
    Constant Field Values
  - USB
```
private static final int[] USB
```
  - USB_INIT
```
private static final int USB_INIT
```
    See Also:
    
    Constant Field Values
  - USB_XOROUT
```
private static final int USB_XOROUT
```
    See Also:
    
    Constant Field Values
  - crc
```
private int crc
```
    CRC.
  - init
```
private final int init
```
  - table
```
private final int[] table
```
  - xorOut
```
private final int xorOut
```
- Constructor Detail
  - Crc16
```
private Crc16(Crc16.Builder builder)
```
    Constructs a new instance.
- Method Detail
  - arc
```
public static Crc16 arc()
```
    Creates a new CRC16-CCITT Checksum.
    
    The init value is 0x0000.
    
    The XorOut value is 0x0000.
    
    Also known as:
    
    CRC-16/ARC
    
    ARC
    
    CRC-16
    
    CRC-16/LHA
    
    CRC-IBM
    Returns:
    
    a new CRC16-CCITT Checksum.
  - builder
```
public static Crc16.Builder builder()
```
    Creates a new builder.
    Since there are so many CRC-16 variants, we do not pick a default.
    
    Returns:
    
    a new builder.
  - ccitt
```
public static Crc16 ccitt()
```
    Creates a new CRC16-CCITT Checksum.
    
    The init value is 0x0000.
    
    The XorOut value is 0x0000.
    
    Also known as:
    
    CRC-16/KERMIT
    
    CRC-16/BLUETOOTH
    
    CRC-16/CCITT
    
    CRC-16/CCITT-TRUE
    
    CRC-16/V-41-LSB
    
    CRC-CCITT
    
    KERMIT
    Returns:
    
    a new CRC16-CCITT Checksum.
  - dnp
```
public static Crc16 dnp()
```
    Creates a new CRC16-DNP Checksum.
    
    The init value is 0x0000.
    
    The XorOut value is 0xFFFF.
    Returns:
    
    a new CRC16-DNP Checksum.
  - getArcTable
```
public static int[] getArcTable()
```
    Gets a copy of the CRC16-CCITT table.
    
    Returns:
    
    a copy of the CCRC16-CITT table.
  - getCcittTable
```
public static int[] getCcittTable()
```
    Gets a copy of the CRC16-CCITT table.
    
    Returns:
    
    a copy of the CCRC16-CITT table.
  - getDnpTable
```
public static int[] getDnpTable()
```
    Gets a copy of the CRC16-DNP table.
    
    Returns:
    
    a copy of the CCRC16-DNP table.
  - getIbmSdlcTable
```
public static int[] getIbmSdlcTable()
```
    Gets a copy of the CRC16-IBM-SDLC table.
    
    Returns:
    
    a copy of the CRC16-IBM-SDLC table.
  - getMaximTable
```
public static int[] getMaximTable()
```
    Gets a copy of the CRC16-MAXIM table.
    
    Returns:
    
    a copy of the CRC16-MAXIM table.
  - getMcrf4xxTable
```
public static int[] getMcrf4xxTable()
```
    Gets a copy of the CRC16-MCRF4XX table.
    
    Returns:
    
    a copy of the CRC16-MCRF4XX table.
  - getModbusTable
```
public static int[] getModbusTable()
```
    Gets a copy of the CRC16-MODBUS table.
    
    Returns:
    
    a copy of the CRC16-MODBUS table.
  - getNrsc5Table
```
public static int[] getNrsc5Table()
```
    Gets a copy of the CRC16-NRSC-5 table.
    
    Returns:
    
    a copy of the CRC16-NRSC-5 table.
  - ibmSdlc
```
public static Crc16 ibmSdlc()
```
    Creates a new CRC16-IBM-SDLC Checksum.
    
    The init value is 0xFFFF.
    
    The XorOut value is 0xFFFF.
    
    Also known as:
    
    CRC-16/IBM-SDLC
    
    CRC-16/ISO-HDLC
    
    CRC-16/ISO-IEC-14443-3-B
    
    CRC-16/X-25
    
    CRC-B
    
    X-25
    Returns:
    
    a new CRC16-IBM-SDLC Checksum.
  - maxim
```
public static Crc16 maxim()
```
    Creates a new instance for CRC16-MAXIM Checksum.
    CRC-16 checksum implementation based on polynomial x<sup>16</spu> + x^15 + x^2 + 1 (0x8005).
    
    The init value is 0xFFFF.
    
    The XorOut value is 0xFFFF.
    
    Also known as:
    
    CRC-16/MAXIM-DOW
    Returns:
    
    a new CRC16-MAXIM Checksum.
  - mcrf4xx
```
public static Crc16 mcrf4xx()
```
    Creates a new instance for CRC16-MCRF4XX Checksum.
    
    The init value is 0xFFFF.
    
    The XorOut value is 0x0000.
    Returns:
    
    a new CRC16-MCRF4XX Checksum.
  - modbus
```
public static Crc16 modbus()
```
    Creates a new instance for CRC16-MODBUS Checksum.
    CRC-16 checksum implementation based on polynomial x<sup>16</spu> + x^15 + x^2 + 1 (0x8005).
    
    The init value is 0xFFFF.
    
    The XorOut value is 0x0000.
    
    Also known as:
    
    CRC-16/MODBUST
    
    MODBUST
    Returns:
    
    a new CRC16-MODBUS Checksum.
  - nrsc5
```
public static Crc16 nrsc5()
```
    Creates a new instance for CRC16-NRSC-5 Checksum.
    
    The init value is 0xFFFF.
    
    The XorOut value is 0x0000.
    Returns:
    
    a new CRC16-NRSC-5 Checksum.
  - usb
```
public static Crc16 usb()
```
    Creates a new instance for CRC16-USB Checksum.
    
    The init value is 0xFFFF.
    
    The XorOut value is 0xFFFF.
    Returns:
    
    a new CRC16-USB Checksum.
  - getValue
```
public long getValue()
```
    Specified by:
    
    getValue in interface java.util.zip.Checksum
  - reset
```
public void reset()
```
    Specified by:
    
    reset in interface java.util.zip.Checksum
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
  - update
```
public void update(byte[] b,
                   int off,
                   int len)
```
    Specified by:
    
    update in interface java.util.zip.Checksum
  - update
```
public void update(int b)
```
    Specified by:
    
    update in interface java.util.zip.Checksum

Class Crc16

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ARC

ARC_INIT

CCITT

CCITT_INIT

DNP

DNP_INIT

DNP_XOROUT

IBM_SDLC

IBM_SDLC_INIT

IBM_SDLC_XOROUT

MAXIM

MAXIM_INIT

MAXIM_XOROUT

MCRF4XX

MCRF4XX_INIT

MODBUS

MODBUS_INIT

NRSC5

NRSC5_INIT

USB

USB_INIT

USB_XOROUT

crc

init

table

xorOut

Constructor Detail

Crc16

Method Detail

arc

builder

ccitt

dnp

getArcTable

getCcittTable

getDnpTable

getIbmSdlcTable

getMaximTable

getMcrf4xxTable

getModbusTable

getNrsc5Table

ibmSdlc

maxim

mcrf4xx

modbus

nrsc5

usb

getValue

reset

toString

update

update