Module org.snmp4j
Package org.snmp4j.smi

Interface Variable

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static long serialVersionUID
      This definition of a serialVersionUID for the Variable interface has been made for backward compatibility with SNMP4J 1.7.x or earlier serialized Variable instances.

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      java.lang.Object clone()
      Clones this variable.
      int compareTo​(Variable o)  
      boolean equals​(java.lang.Object o)  
      void fromSubIndex​(OID subIndex, boolean impliedLength)
      Sets the value of this Variable from the supplied (sub-)index.
      int getSyntax()
      Gets the ASN.1 syntax identifier value of this SNMP variable.
      java.lang.String getSyntaxString()
      Gets a textual description of this Variable.
      int hashCode()  
      boolean isDynamic()
      Indicates whether this variable is dynamic.
      boolean isException()
      Checks whether this variable represents an exception like noSuchObject, noSuchInstance, and endOfMibView.
      int toInt()
      Returns an integer representation of this variable if such a representation exists.
      long toLong()
      Returns a long representation of this variable if such a representation exists.
      java.lang.String toString()
      Gets a string representation of the variable.
      OID toSubIndex​(boolean impliedLength)
      Converts the value of this Variable to a (sub-)index value.

    • Field Detail

      • serialVersionUID

        static final long serialVersionUID
        This definition of a serialVersionUID for the Variable interface has been made for backward compatibility with SNMP4J 1.7.x or earlier serialized Variable instances.
        See Also:
        Constant Field Values

    • Method Detail

      • equals

        boolean equals​(java.lang.Object o)
        Overrides:
        equals in class java.lang.Object

      • compareTo

        int compareTo​(Variable o)
        Specified by:
        compareTo in interface java.lang.Comparable<Variable>

      • hashCode

        int hashCode()
        Overrides:
        hashCode in class java.lang.Object

      • clone

        java.lang.Object clone()
        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.
        Returns:
        a new instance of this Variable with the same value.

      • getSyntax

        int getSyntax()
        Gets the ASN.1 syntax identifier value of this SNMP variable.
        Returns:
        an integer value < 128 for regular SMI objects and a value >= 128 for exception values like noSuchObject, noSuchInstance, and endOfMibView.

      • toString

        java.lang.String toString()
        Gets a string representation of the variable.
        Overrides:
        toString in class java.lang.Object
        Returns:
        a string representation of the variable's value.

      • toInt

        int toInt()
        Returns an integer representation of this variable if such a representation exists.
        Returns:
        an integer value (if the native representation of this variable would be a long, then the long value will be casted to int).
        Throws:
        java.lang.UnsupportedOperationException - if an integer representation does not exists for this Variable.

      • toLong

        long toLong()
        Returns a long representation of this variable if such a representation exists.
        Returns:
        a long value.
        Throws:
        java.lang.UnsupportedOperationException - if a long representation does not exists for this Variable.

      • getSyntaxString

        java.lang.String getSyntaxString()
        Gets a textual description of this Variable.
        Returns:
        a textual description like 'Integer32' as used in the Structure of Management Information (SMI) modules. '?' is returned if the syntax is unknown.

      • toSubIndex

        OID toSubIndex​(boolean impliedLength)
        Converts the value of this Variable to a (sub-)index value.
        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.
        Throws:
        java.lang.UnsupportedOperationException - if this variable cannot be used in an index.

      • fromSubIndex

        void fromSubIndex​(OID subIndex,
                  boolean impliedLength)
        Sets the value of this Variable from the supplied (sub-)index.
        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.
        Throws:
        java.lang.UnsupportedOperationException - if this variable cannot be used in an index.

      • isDynamic

        boolean isDynamic()
        Indicates whether this variable is dynamic. If a variable is dynamic, precautions have to be taken when a Variable is serialized using BER encoding, because between determining the length with BERSerializable.getBERLength() for encoding enclosing SEQUENCES and the actual encoding of the Variable itself with BERSerializable.encodeBER(java.io.OutputStream) changes to the value need to be blocked by synchronization. In order to ensure proper synchronization if a Variable is dynamic, modifications of the variables content need to synchronize on the Variable instance. This can be achieved for the standard SMI Variable implementations for example by 
            public static modifyVariable(Integer32 variable, int value)
      synchronize(variable) {
        variable.setValue(value);
      }
    }
        Returns:
        true if the variable might change its value between two calls to BERSerializable.getBERLength() and BERSerializable.encodeBER(java.io.OutputStream) and false if the value is immutable or if its value does not change while serialization because of measures taken by the implementor (i.e. variable cloning).