Package org.snmp4j.smi

Class Null

java.lang.Object

org.snmp4j.smi.AbstractVariable

org.snmp4j.smi.Null

All Implemented Interfaces:

Serializable, Cloneable, Comparable<Variable>, BERSerializable, Variable

public class Null
extends AbstractVariable

The Null class represents SMI Null and the derived SMIv2 exception syntaxes.

Version:

1.8

Author:

Frank Fock

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static final Null	endOfMibView
static final Null	instance
static final Null	noSuchInstance
static final Null	noSuchObject

Fields inherited from class org.snmp4j.smi.AbstractVariable

SMISYNTAXES_PROPERTIES

Constructor Summary

Constructors

Constructor	Description
Null()
Null(int exceptionSyntax)

Method Summary

Modifier and Type	Method	Description
Object	clone()	Clones this variable.
int	compareTo(Variable o)
void	decodeBER(BERInputStream inputStream)	Decodes a Variable from an BERInputStream.
void	encodeBER(OutputStream outputStream)	Encodes a Variable to an OutputStream.
boolean	equals(Object o)
void	fromSubIndex(OID subIndex, boolean impliedLength)	Sets the value of this Variable from the supplied (sub-)index.
int	getBERLength()	Returns the length of this Variable in bytes when encoded according to the Basic Encoding Rules (BER).
int	getSyntax()	Gets the ASN.1 syntax identifier value of this SNMP variable.
int	hashCode()
static boolean	isExceptionSyntax(int syntax)
void	setSyntax(int syntax)
final int	toInt()	Returns the syntax of this Null variable.
final long	toLong()	Returns the syntax of this Null variable.
String	toString()	Gets a string representation of the variable.
OID	toSubIndex(boolean impliedLength)	Converts the value of this Variable to a (sub-)index value.

Methods inherited from class org.snmp4j.smi.AbstractVariable

createFromBER, createFromSyntax, equal, getBERPayloadLength, getSyntaxFromString, getSyntaxString, getSyntaxString, isDynamic, isException

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

noSuchObject

public static final Null noSuchObject

noSuchInstance

public static final Null noSuchInstance

endOfMibView

public static final Null endOfMibView

instance

public static final Null instance

Constructor Details

Null

public Null()

Null

public Null(int exceptionSyntax)

Method Details

decodeBER

public void decodeBER(BERInputStream inputStream)
               throws IOException

Description copied from class: AbstractVariable

Decodes a Variable from an BERInputStream.

Specified by:

decodeBER in interface BERSerializable

Specified by:

decodeBER in class AbstractVariable

Parameters:

inputStream - an BERInputStream containing a BER encoded byte stream.

Throws:

IOException - if the stream could not be decoded by using BER rules.

getSyntax

public int getSyntax()

Description copied from class: AbstractVariable

Gets the ASN.1 syntax identifier value of this SNMP variable.

Specified by:

getSyntax in interface Variable

Specified by:

getSyntax in class AbstractVariable

Returns:

an integer value less than 128 for regular SMI objects and a value greater or equal than 128 for exception values like noSuchObject, noSuchInstance, and endOfMibView.

hashCode

public int hashCode()

Specified by:

hashCode in interface Variable

Specified by:

hashCode in class AbstractVariable

getBERLength

public int getBERLength()

Description copied from class: AbstractVariable

Returns the length of this Variable in bytes when encoded according to the Basic Encoding Rules (BER).

Specified by:

getBERLength in interface BERSerializable

Specified by:

getBERLength in class AbstractVariable

Returns:

the BER encoded length of this variable.

equals

public boolean equals(Object o)

Specified by:

equals in interface Variable

Specified by:

equals in class AbstractVariable

compareTo

public int compareTo(Variable o)

Specified by:

compareTo in interface Comparable<Variable>

Specified by:

compareTo in interface Variable

Specified by:

compareTo in class AbstractVariable

toString

public String toString()

Description copied from class: AbstractVariable

Gets a string representation of the variable.

Specified by:

toString in interface Variable

Specified by:

toString in class AbstractVariable

Returns:

a string representation of the variable's value.

encodeBER

public void encodeBER(OutputStream outputStream)
               throws IOException

Description copied from class: AbstractVariable

Encodes a Variable to an OutputStream.

Specified by:

encodeBER in interface BERSerializable

Specified by:

encodeBER in class AbstractVariable

Parameters:

outputStream - an OutputStream.

Throws:

IOException - if an error occurs while writing to the stream.

setSyntax

public void setSyntax(int syntax)

clone

public Object clone()

Description copied from interface: Variable

Clones this variable. Cloning can be used by the SNMP4J API to better support concurrency by creating a clone for internal processing. The content of this object is independent to the content of the clone. Thus, changes to the clone will have no effect to this object.

Specified by:

clone in interface Variable

Specified by:

clone in class AbstractVariable

Returns:

a new instance of this Variable with the same value.

isExceptionSyntax

public static boolean isExceptionSyntax(int syntax)

toInt

public final int toInt()

Returns the syntax of this Null variable.

Specified by:

toInt in interface Variable

Specified by:

toInt in class AbstractVariable

Returns:

SMIConstants.SYNTAX_NULL or one of the exception syntaxes SMIConstants.EXCEPTION_NO_SUCH_OBJECT, SMIConstants.EXCEPTION_NO_SUCH_INSTANCE, or SMIConstants.EXCEPTION_END_OF_MIB_VIEW

Since:

1.7

toLong

public final long toLong()

Returns the syntax of this Null variable.

Specified by:

toLong in interface Variable

Specified by:

toLong in class AbstractVariable

Returns:

SMIConstants.SYNTAX_NULL or one of the exception syntaxes SMIConstants.EXCEPTION_NO_SUCH_OBJECT, SMIConstants.EXCEPTION_NO_SUCH_INSTANCE, or SMIConstants.EXCEPTION_END_OF_MIB_VIEW

Since:

1.7

toSubIndex

public OID toSubIndex(boolean impliedLength)

Description copied from class: AbstractVariable

Converts the value of this Variable to a (sub-)index value.

Specified by:

toSubIndex in interface Variable

Specified by:

toSubIndex in class AbstractVariable

Parameters:

impliedLength - specifies if the sub-index has an implied length. This parameter applies to variable length variables only (e.g. OctetString and OID). For other variables it has no effect.

Returns:

an OID that represents this value as an (sub-)index.

fromSubIndex

public void fromSubIndex(OID subIndex,
 boolean impliedLength)

Description copied from class: AbstractVariable

Sets the value of this Variable from the supplied (sub-)index.

Specified by:

fromSubIndex in interface Variable

Specified by:

fromSubIndex in class AbstractVariable

Parameters:

subIndex - the sub-index OID.

impliedLength - specifies if the sub-index has an implied length. This parameter applies to variable length variables only (e.g. OctetString and OID). For other variables it has no effect.