public class SEQUENCE extends ConstructedType
A SEQUENCE object is DER encoded using the constructed encoding practice
by splitting it into separately encoded components. Therefore the SEQUENCE class is
extended to be a subclass of the ConstructedType
class. Each component can be added to the current SEQUENCE object by using a proper
addComponent method of
the ConstructedType super class.
The constructed form can be recognized by bit 6 of the (first) identifier octet(s) of the DER encoded bit stream, which is set to 1.
When creating a new SEQUENCE object, explicitly may be specified to
use indefinite length encoding instead of definite length encodÃng. Indefinite
length encoding is recognized by a length tag of (hexadecimal) 0x80, and the
content octets are concluded by two consecutive octets of all zeros:
0x30 0x80
...
-- content octets
...
0x00 0x00 -- EOC octets
instead of explicitly specifying the number of content octets (definite length
encoding):
0x30 0x07 ... -- seven content octets ...Indefinite length encoding may be preferable when the actual number of content octets is not known at the beginning of the data transfer.
When using indefinite length encoding, the encodeTo method of the DerCoder class shall be used instead
of the encode method, in particular when dealing with large amounts of data.
The following example creates a new SEQUENCE object and adds an INTERGER, BOOLEAN, and a PrintableString component:
SEQUENCE seq = new SEQUENCE();
seq.addComponent(new INTEGER(3));
seq.addComponent(new BOOLEAN(true));
seq.addComponent(new PrintableString("Test"));
Of course, sequences may be nested meaning that one SEQUENCE contains another
SEQUENCE as one of its components. The nesting may be of any depth.content_count, content_dataasnType, constructed, encode_listener, indefinite_length, isStringType, stream_mode| Constructor and Description |
|---|
SEQUENCE()
Creates a new SEQUENCE.
|
SEQUENCE(boolean indefiniteLength)
Creates a new SEQUENCE and defines the length encoding method to be used.
|
| Modifier and Type | Method and Description |
|---|---|
java.lang.String |
toString()
Returns a String that represents the value of this SEQUENCE.
|
addComponent, addComponent, addEncodeListener, countComponents, decode, encode, getComponentAt, getComponents, getValue, removeComponent, removeComponent, setComponent, setValueaddEncodeListener, encodeObject, getAsnType, indefiniteLength, isA, isConstructed, isStringType, setAutomaticRepair, setAutomaticRepairRecursive, setIndefiniteLength, setIndefiniteRecursivepublic SEQUENCE()
Components may be added by means of the addComponent method of the ConstructedType
super class. Length encoding will be definite.
public SEQUENCE(boolean indefiniteLength)
Components may be added by means of the addComponent method of the ConstructedType
super class. If indefiniteLength is set to true,
the indefinte length method will be used when actually DER encoding this
SEQUENCE, otherwise the definite length encoding method will be used.
indefiniteLength - whether to use definite or indefinte length encoding
when DER encoding this SEQUENCEpublic java.lang.String toString()
toString in class ASN1ObjectASN1Object.toString()