spki
Class Tag

java.lang.Object
  |
  +--spki.BaseObj
        |
        +--spki.Tag

public class Tag

extends BaseObj

spki Tag class.

Formal definitions:

 <tag-star>:: "(*)" ;
 <tag-expr>:: <tag-star> | <s-expr> ;
 <tag>:: "(" "tag" <tag-expr>? ")" ;
 

Version:

$Id: Tag.java,v 1.10 2002/06/23 19:09:43 tep Exp $

Author:

Tep Narula <tep@win.trlabs.ca>

Field Summary

private static String	__ME This class's full name.
private boolean	is_wildcard Is this a wildcard tag?
static String	SEXP_NAME This class S-Expression type name, used by toSExpression() and other methods.
private SList	tag_expr This object's tag-expression, maybe null for empty tag.
static String	TAG_STAR The universal wild-card tag-expression, which will intersect with any tag-expression.

Fields inherited from class spki.BaseObj

__ME, cache_sexp, cached_sexp, DEFAULT_HASH_ALG, locked, SEXP_NAME

Constructor Summary

Tag()
Create an immutable empty Tag object with no tag-expression.

Tag(SExpression sexp)
Create an immutable Tag object from an S-Expression.

Tag(SList tag_expr)
Create an immutable Tag object with the given tag-expression.

Method Summary

SList	getTagExpr() Get the tag-expression, if available.
boolean	isEmptyTag() Is this an empty tag?
boolean	isWildcardTag() Is this a wildcard tag?
private void	setTagExpr(SList tag_expr) Store the tag-expression.
SExpression	toSExpression() Build an SExpression representing this object.

Methods inherited from class spki.BaseObj

disableSExpressionCaching, enableSExpressionCaching, extractHashAlgId, getCachedSExpression, isLocked, isSListOfType, lock, providerToSPKI, setCachedSExpression, spkiToProvider, toString

Methods inherited from class java.lang.Object

, clone, equals, finalize, getClass, hashCode, notify, notifyAll, registerNatives, wait, wait, wait

Field Detail

__ME

private static final String __ME

This class's full name.

SEXP_NAME

public static final String SEXP_NAME

This class S-Expression type name, used by toSExpression() and other methods.

See Also:

toSExpression()

TAG_STAR

public static final String TAG_STAR

The universal wild-card tag-expression, which will intersect with any tag-expression.

is_wildcard

private boolean is_wildcard

Is this a wildcard tag?

See Also:

isWildcardTag()

tag_expr

private SList tag_expr

This object's tag-expression, maybe null for empty tag.

See Also:

getTagExpr(), setTagExpr(SList)

Constructor Detail

Tag

public Tag()

Create an immutable empty Tag object with no tag-expression.

See Also:

Tag(SExpression), Tag(SList)

Tag

public Tag(SExpression sexp)
    throws SPKIException,
           ParseException

Create an immutable Tag object from an S-Expression. IMPORTANT: Beware of argument type confusion between this constructor and Tag(SList) constructor. To be safe, explicitly cast the argument into SExpression when constructing a Tag object from an S-Expression-encoded authorization tag.

See Also:

Tag(SList), BaseObj.BaseObj(SExpression)

Tag

public Tag(SList tag_expr)
    throws SPKIException

Create an immutable Tag object with the given tag-expression. IMPORTANT: Beware of argument-type confusion between this constructor and the Tag(SExpression) constructor. To be safe, explicityly cast the argument into SList when constructing a Tag object from a tag-expression. Also, passing (SList) null as the argument is not the same as passing no argument, which will invoke the default constructor to create an empty tag.

Parameters:

tag_expr - the tag-expression to be stored, or null to create a wildcard tag.

Throws:

SPKIException - if something went wrong.

See Also:

Tag(SExpression), Tag()

Method Detail

toSExpression

public SExpression toSExpression()
                          throws SPKIException

Description copied from interface: SPKIObject

Build an SExpression representing this object.

Overrides:

toSExpression in class BaseObj

Tags copied from interface: SPKIObject

Returns:

SExpression object representing this object, or null.

Throws:

SPKIException - if something went wrong during conversion.

getTagExpr

public SList getTagExpr()
                 throws SPKIException

Get the tag-expression, if available.

Returns:

SList object containing tag-expression, or null.

Throws:

SPKIException - if something went wrong.

isWildcardTag

public boolean isWildcardTag()

Is this a wildcard tag?

Returns:

true if this is a wildcard tag, false otherwise.

See Also:

TAG_STAR

isEmptyTag

public boolean isEmptyTag()

Is this an empty tag?

Returns:

true if this is an empty tag, false otherwise.

setTagExpr

private void setTagExpr(SList tag_expr)
                 throws IllegalStateException,
                        SPKIException

Store the tag-expression.

Parameters:

tag_expr - the tag-expression to store.

Throws:

IllegalStateException - if the object is immutable.

SPKIException - if something went wrong.