java.lang.Object
- org.apache.directory.api.asn1.util.Oid

```
public final class Oid
extends Object
```
An immutable representation of an object identifier that provides conversion between their String, and encoded byte[] representations.
The encoding of OID values is performed according to itu X.690 section 8.19. Specifically:

8.19.2 The contents octets shall be an (ordered) list of encodings of subidentifiers (see 8.19.3 and 8.19.4) concatenated together. Each subidentifier is represented as a series of (one or more) octets. Bit 8 of each octet indicates whether it is the last in the series: bit 8 of the last octet is zero; bit 8 of each preceding octet is one. Bits 7 to 1 of the octets in the series collectively encode the subidentifier. Conceptually, these groups of bits are concatenated to form an unsigned binary number whose most significant bit is bit 7 of the first octet and whose least significant bit is bit 1 of the last octet. The subidentifier shall be encoded in the fewest possible octets, that is, the leading octet of the subidentifier shall not have the value 0x80.

8.19.3 The number of subidentifiers (N) shall be one less than the number of object identifier components in the object identifier value being encoded.

8.19.4 The numerical value of the first subidentifier is derived from the values of the first two object identifier components in the object identifier value being encoded, using the formula:
(X*40) + Y
where X is the value of the first object identifier component and Y is the value of the second object identifier component. NOTE – This packing of the first two object identifier components recognizes that only three values are allocated from the root node, and at most 39 subsequent values from nodes reached by X = 0 and X = 1.

For example, the OID "2.12.3456.7" would be turned into a list of 3 values: [((2*40)+12), 3456, 7]. The first of which, 92, would be encoded as the bytes 0x5C, the second would be [0x9B, 0x00], and the third as 0x07 giving the final encoding [0x5C, 0x9B, 0x00, 0x07].

Author:

Apache Directory Project

Nested Class Summary

Nested Classes
Modifier and Type Class Description

private static class Oid.OidFSAState
The OID FSA states.

Field Summary

Fields
Modifier and Type	Field	Description
`private static BigInteger`	`JOINT_ISO_ITU_T`
`private byte[]`	`oidBytes`	A byte[] representation of an OID
`private String`	`oidString`	The OID as a String

Constructor Summary

Constructors
Modifier Constructor Description

private Oid(String oidString, byte[] oidBytes)
Creates a new instance of Oid.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`private static int`	`convert(String oid, byte[] buffer, int start, int nbDigits, int posBuffer, boolean isJointIsoItuT)`	Convert a list of digits to a list of 7 bits bytes.
`boolean`	`equals(Object other)`
`static Oid`	`fromBytes(byte[] oidBytes)`	Decodes an OID from a `byte[]`.
`static Oid`	`fromString(String oidString)`	Returns an OID object representing `oidString`.
`int`	`getEncodedLength()`	Returns the length of the encoded `byte[]` representation.
`int`	`hashCode()`
`static boolean`	`isOid(String oidString)`	Returns true if `oidString` is a valid string representation of an OID.
`private static Oid.OidFSAState`	`processStateA(String oid, int pos)`	Process state B
`private static Oid.OidFSAState`	`processStateB(String oid, byte[] buffer, int pos)`	Process state B
`private static Oid.OidFSAState`	`processStateC(String oid, byte[] buffer, int pos)`	Process state C
`private static Oid.OidFSAState`	`processStateDE(String oid, byte[] buffer, int pos)`	Process state D and E
`private static Oid.OidFSAState`	`processStateF(String oid, int pos)`	Process state F
`private static Oid.OidFSAState`	`processStateG(String oid, byte[] buffer, int pos)`	Process state G
`private static Oid.OidFSAState`	`processStateH(String oid, byte[] buffer, int pos)`	Process state H
`private static Oid.OidFSAState`	`processStateI(String oid, byte[] buffer, int pos)`	Process state I
`private static Oid.OidFSAState`	`processStateJ(String oid, byte[] buffer, int bufferPos, int pos)`	Process state J
`private static Oid.OidFSAState`	`processStateK(String oid, byte[] buffer, int bufferPos, int pos)`	Process state J
`private static Oid.OidFSAState`	`processStateL(String oid, byte[] buffer, int bufferPos, int pos)`	Process state J
`private static Oid.OidFSAState`	`processStateM(String oid, int pos)`	Process state J
`private static Oid.OidFSAState`	`processStateStart(String oid, byte[] buffer, int pos)`	Process state A
`byte[]`	`toBytes()`	Returns the `byte[]` representation of the OID.
`String`	`toString()`	Returns the string representation of the OID.
`void`	`writeBytesTo(OutputStream outputStream)`	Writes the bytes respresenting this OID to the provided stream.
`void`	`writeBytesTo(ByteBuffer buffer)`	Writes the bytes respresenting this OID to the provided buffer.

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

- Field Detail
  - oidBytes
```
private byte[] oidBytes
```
    A byte[] representation of an OID
  - oidString
```
private String oidString
```
    The OID as a String
  - JOINT_ISO_ITU_T
```
private static final BigInteger JOINT_ISO_ITU_T
```
- Constructor Detail
  - Oid
```
private Oid(String oidString,
            byte[] oidBytes)
```
    Creates a new instance of Oid.
    
    Parameters:
    
    oidString - The OID as a String
    
    oidBytes - The OID as a byte[]
- Method Detail
  - equals
```
public boolean equals(Object other)
```
    Overrides:
    
    equals in class Object
  - fromBytes
```
public static Oid fromBytes(byte[] oidBytes)
                     throws DecoderException
```
    Decodes an OID from a byte[].
    
    Parameters:
    
    oidBytes - The encodedbyte[]
    
    Returns:
    
    A new Oid
    
    Throws:
    
    DecoderException - When the OID is not valid
  - processStateStart
```
private static Oid.OidFSAState processStateStart(String oid,
                                                 byte[] buffer,
                                                 int pos)
                                          throws DecoderException
```
    Process state A
    (Start) --['0','1']--> (A) (start) --['2']--> (F)
    Parameters:
    
    oid - The OID to check
    
    buffer - The buffer gathering the binary OID
    
    pos - The position in the OID string
    
    Returns:
    
    The next OID decoding state
    
    Throws:
    
    DecoderException - If the OID is invalid
  - processStateA
```
private static Oid.OidFSAState processStateA(String oid,
                                             int pos)
                                      throws DecoderException
```
    Process state B
    (A) --['.']--> (B)
    Parameters:
    
    oid - The OID to check
    
    pos - The position in the OID string
    
    Returns:
    
    The next OID decoding state
    
    Throws:
    
    DecoderException - If the OID is invalid
  - processStateB
```
private static Oid.OidFSAState processStateB(String oid,
                                             byte[] buffer,
                                             int pos)
                                      throws DecoderException
```
    Process state B
    (B) --['0']--> (D) (B) --['1'..'3']--> (C) (B) --['4'..'9']--> (E)
    Parameters:
    
    oid - The OID to check
    
    buffer - The buffer gathering the binary OID
    
    pos - The position in the OID string
    
    Returns:
    
    The next OID decoding state
    
    Throws:
    
    DecoderException - If the OID is invalid
  - processStateC
```
private static Oid.OidFSAState processStateC(String oid,
                                             byte[] buffer,
                                             int pos)
                                      throws DecoderException
```
    Process state C
    (C) --['.']--> (K) (C) --['0'..'9']--> (E)
    Parameters:
    
    oid - The OID to check
    
    buffer - The buffer gathering the binary OID
    
    pos - The position in the OID string
    
    Returns:
    
    The next OID decoding state
    
    Throws:
    
    DecoderException - If the OID is invalid
  - processStateDE
```
private static Oid.OidFSAState processStateDE(String oid,
                                              byte[] buffer,
                                              int pos)
                                       throws DecoderException
```
    Process state D and E
    (D) --['.']--> (K) (E) --['.']--> (K)
    Parameters:
    
    oid - The OID to check
    
    buffer - The buffer gathering the binary OID
    
    pos - The position in the OID string
    
    Returns:
    
    The next OID decoding state
    
    Throws:
    
    DecoderException - If the OID is invalid
  - processStateF
```
private static Oid.OidFSAState processStateF(String oid,
                                             int pos)
                                      throws DecoderException
```
    Process state F
    (F) --['.']--> (G)
    Parameters:
    
    oid - The OID to check
    
    pos - The position in the OID string
    
    Returns:
    
    The next OID decoding state
    
    Throws:
    
    DecoderException - If the OID is invalid
  - processStateG
```
private static Oid.OidFSAState processStateG(String oid,
                                             byte[] buffer,
                                             int pos)
                                      throws DecoderException
```
    Process state G
    (G) --['0']--> (I) (G) --['1'..'9']--> (H)
    Parameters:
    
    oid - The OID to check
    
    buffer - The buffer gathering the binary OID
    
    pos - The position in the OID string
    
    Returns:
    
    The next OID decoding state
    
    Throws:
    
    DecoderException - If the OID is invalid
  - processStateH
```
private static Oid.OidFSAState processStateH(String oid,
                                             byte[] buffer,
                                             int pos)
                                      throws DecoderException
```
    Process state H
    (H) --['.']--> (K) (H) --['0'..'9']--> (J)
    Parameters:
    
    oid - The OID to check
    
    buffer - The buffer gathering the binary OID
    
    pos - The position in the OID string
    
    Returns:
    
    The next OID decoding state
    
    Throws:
    
    DecoderException - If the OID is invalid
  - processStateI
```
private static Oid.OidFSAState processStateI(String oid,
                                             byte[] buffer,
                                             int pos)
                                      throws DecoderException
```
    Process state I
    (I) --['.']--> (K)
    Parameters:
    
    oid - The OID to check
    
    buffer - The buffer gathering the binary OID
    
    pos - The position in the OID string
    
    Returns:
    
    The next OID decoding state
    
    Throws:
    
    DecoderException - If the OID is invalid
  - processStateJ
```
private static Oid.OidFSAState processStateJ(String oid,
                                             byte[] buffer,
                                             int bufferPos,
                                             int pos)
                                      throws DecoderException
```
    Process state J
    (J) --['.']--> (K) (J) --['0'..'9']--> (J)
    Parameters:
    
    oid - The OID to check
    
    buffer - The buffer gathering the binary OID
    
    bufferPos - The current position in the buffer
    
    pos - The position in the OID string
    
    Returns:
    
    The next OID decoding state
    
    Throws:
    
    DecoderException - If the OID is invalid
  - processStateK
```
private static Oid.OidFSAState processStateK(String oid,
                                             byte[] buffer,
                                             int bufferPos,
                                             int pos)
                                      throws DecoderException
```
    Process state J
    (K) --['0']--> (M) (K) --['1'..'9']--> (L)
    Parameters:
    
    oid - The OID to check
    
    buffer - The buffer gathering the binary OID
    
    bufferPos - The current position in the buffer
    
    pos - The position in the OID string
    
    Returns:
    
    The next OID decoding state
    
    Throws:
    
    DecoderException - If the OID is invalid
  - processStateL
```
private static Oid.OidFSAState processStateL(String oid,
                                             byte[] buffer,
                                             int bufferPos,
                                             int pos)
                                      throws DecoderException
```
    Process state J
    (L) --['.']--> (K) (L) --['0'..'9']--> (L)
    Parameters:
    
    oid - The OID to check
    
    buffer - The buffer gathering the binary OID
    
    bufferPos - The current position in the buffer
    
    pos - The position in the OID string
    
    Returns:
    
    The next OID decoding state
    
    Throws:
    
    DecoderException - If the OID is invalid
  - processStateM
```
private static Oid.OidFSAState processStateM(String oid,
                                             int pos)
                                      throws DecoderException
```
    Process state J
    (M) --['.']--> (K)
    Parameters:
    
    oid - The OID to check
    
    pos - The position in the OID string
    
    Returns:
    
    The next OID decoding state
    
    Throws:
    
    DecoderException - If the OID is invalid
  - convert
```
private static int convert(String oid,
                           byte[] buffer,
                           int start,
                           int nbDigits,
                           int posBuffer,
                           boolean isJointIsoItuT)
```
    Convert a list of digits to a list of 7 bits bytes. We must start by the end, and we don't know how many bytes we will need, except when we will be done with the conversion.
    
    Parameters:
    
    oid - The OID to convert
    
    buffer - The buffer gathering the binary OID
    
    start - The starting position in the OID string
    
    nbDigits - Teh number of digits the OID has
    
    posBuffer - The position in the buffer
    
    isJointIsoItuT - A flag set if we know the OID is a JointIsoItuT OID
    
    Returns:
    
    The number of bytes required to store the OID in a PDU
  - fromString
```
public static Oid fromString(String oidString)
                      throws DecoderException
```
    Returns an OID object representing oidString.
    
    Parameters:
    
    oidString - The string representation of the OID
    
    Returns:
    
    A new Oid
    
    Throws:
    
    DecoderException - When the OID is not valid
  - getEncodedLength
```
public int getEncodedLength()
```
    Returns the length of the encoded byte[] representation.
    
    Returns:
    
    The length of the byte[]
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - isOid
```
public static boolean isOid(String oidString)
```
    Returns true if oidString is a valid string representation of an OID. This method simply calls fromString(String) and returns true if no exception was thrown. As such, it should not be used in an attempt to check if a string is a valid OID before calling fromString(String).
    
    Parameters:
    
    oidString - The string to test
    
    Returns:
    
    True, if oidString is valid
  - toBytes
```
public byte[] toBytes()
```
    Returns the byte[] representation of the OID. The byte[] that is returned is copied from the internal value so as to preserve the immutability of an OID object. If the output of a call to this method is intended to be written to a stream, the writeBytesTo(OutputStream) should be used instead as it will avoid creating this copy.
    
    Returns:
    
    The encoded byte[] representation of the OID.
  - toString
```
public String toString()
```
    Returns the string representation of the OID.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    
    The string representation of the OID
  - writeBytesTo
```
public void writeBytesTo(ByteBuffer buffer)
```
    Writes the bytes respresenting this OID to the provided buffer. This should be used in preference to the toBytes() method in order to prevent the creation of copies of the actual byte[].
    
    Parameters:
    
    buffer - The buffer to write the bytes into
  - writeBytesTo
```
public void writeBytesTo(OutputStream outputStream)
                  throws IOException
```
    Writes the bytes respresenting this OID to the provided stream. This should be used in preference to the toBytes() method in order to prevent the creation of copies of the actual byte[].
    
    Parameters:
    
    outputStream - The stream to write the bytes to
    
    Throws:
    
    IOException - When we can't write the OID into a Stream

Class Oid

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

oidBytes

oidString

JOINT_ISO_ITU_T

Constructor Detail

Oid

Method Detail

equals

fromBytes

processStateStart

processStateA

processStateB

processStateC

processStateDE

processStateF

processStateG

processStateH

processStateI

processStateJ

processStateK

processStateL

processStateM

convert

fromString

getEncodedLength

hashCode

isOid

toBytes

toString

writeBytesTo

writeBytesTo