Class Signal

  • All Implemented Interfaces:
    DataObject, FastSerializable, Serializable

    public final class Signal
    extends AbstractLazyEncodedByteArray
    implements FastSerializable
    Class Signal conveys information to a user concerning tones and alerting signals. It represents the ASN.1 OCTET STRING types Core-INAP-CS1-DataTypes.AlertingPattern and CAP-datatypes.AlertingPattern.

    The API offered by this class is as if the type were specified in ASN.1 as follows.

     Signal ::= SEQUENCE {
         signalValue SignalValue
     }
    The class takes care of encoding the field value into a byte-array and decoding the field value from a byte-array, the encoded representation being as tabulated below.

    Data Encoding - based on ITU-T Q.931 (05/98) §4.5.28 p99
    87654321
    Octet 10Signal information element identifier
    Octet 20Length of signal contents
    Octet 3Signal value

    The octet numbering in the above table is that used in the cited standard.

    Based on Q.931 1998-05 p99, the value of Signal information element identifier is always 0110100, and the value of Length of signal contents is always 0000001.

    Based on ETSI TS 101 046 v7.1.0 p38, the Signal information element identifier and Length of signal contents are both ignored; their values are always 0000000.

    See Also:
    Serialized Form
    • Constructor Detail

      • Signal

        public Signal()
        Constructs a new Signal object with no fields set.
      • Signal

        public Signal​(byte[] data)
        Constructs a new Signal object from network-encoded data. The data is not decoded and might not be decodable.
        Parameters:
        data - network-encoded data
        Throws:
        NullPointerException - if data is null
      • Signal

        public Signal​(byte[] data,
                      int start,
                      int len)
        Constructs a new Signal object from part of network-encoded data. The part starts at index start and is len bytes long. The data is not decoded and might not be decodable.
        Parameters:
        data - network-encoded data
        start - starting offset of network-encoded data in byte array
        len - default length if not predictable
        Throws:
        NullPointerException - if data is null
        IllegalArgumentException - if len is negative
      • Signal

        public Signal​(Signal.SignalValue signalValue)
        Constructs a new Signal object from given values for all fields.
        Parameters:
        signalValue - the signal value
      • Signal

        public Signal​(DataInput in)
               throws IOException
        Constructs a new Signal object from data deserialized from a stream that was written by toStream(DataOutput).
        Parameters:
        in - the stream to read from
        Throws:
        EOFException - if reading is pre-empted by end-of-file
        IOException - if the data cannot be read
    • Method Detail

      • hasSignalValue

        public boolean hasSignalValue()
                               throws DecodeException
        Tests whether the field SignalValue has a value.
        Returns:
        whether the field has a value
        Throws:
        DecodeException - if encoded state cannot be decoded
      • copyOf

        public static Signal copyOf​(Signal from)
        Creates a new object of this type, cloning the values of common fields from the given object of any subclass of the same base type.
        Parameters:
        from - the object from which to copy
        Returns:
        Signal
      • getFieldAccessors

        public static FieldAccessor[] getFieldAccessors()
        Gets a new array of the accessors for fields of this type.
        Returns:
        FieldAccessor[]
      • getFieldsMap

        public Map<String,​Object> getFieldsMap​(boolean withAbsents)
        Gets a Map from field-name to field-value for the fields of a sequence. For a field of primitive type, the field-value is boxed. For an absent optional field, the field-value is AbstractFieldsObject.FIELD_ABSENT. For an uninitialised mandatory field, the field-value is AbstractFieldsObject.FIELD_UNINITIALISED. For a field of String type, the encoded form is used if the String cannot be decoded. For a type that represents an OCTET STRING that cannot be decoded, a map from "encodedValue" to the byte array value is returned.
        Specified by:
        getFieldsMap in class AbstractFieldsObject
        Parameters:
        withAbsents - whether to put absent optional fields into Map
        Returns:
        Map from field-name to field-value
      • encodedIsInvalid

        protected boolean encodedIsInvalid()
        Determines whether the encoded form is invalid.
        Returns:
        boolean
      • getEncodedForm

        public byte[] getEncodedForm()
                              throws EncodeException
        Gets the encoded form.
        Returns:
        encoded form
        Throws:
        EncodeException - if encoding fails
      • getContainedLength

        public static int getContainedLength​(byte[] data,
                                             int start,
                                             int len)
        Determines the length of the encoded value that commences at offset start in the given data. The value is not fully decoded and might not be decodable. Values of this type are of a fixed length, so that length is returned if the data is long enough, otherwise 0 is returned.
        Parameters:
        data - network-encoded data
        start - index into data where value commences
        len - length in data to be considered
        Returns:
        3, or 0 if encoded value is not long enough
      • getInapEncodedForm

        public byte[] getInapEncodedForm()
        Gets the ITU Recommendation Q.931 encoded form of this signal.
        Returns:
        a byte array containing the ITU Recommendation Q.931 encoded form of this signal
      • getCapEncodedForm

        public byte[] getCapEncodedForm()
        Gets the ETSI TS 101 046 v7.1.0 encoded form of this signal.
        Returns:
        a byte array containing the ETSI TS 101 046 v7.1.0 encoded form of this signal