org.ldaptive.asn1

Class DERPath

java.lang.Object

org.ldaptive.asn1.DERPath

public class DERPath
extends Object

Describes paths to individual elements of an encoded DER object that may be addressed during parsing to associate a parsed element with a handler to handle that element. Consider the following production rule for a complex type that may be DER encoded:

     BankAccountSet ::= SET OF {
       account BankAccount
     }

     BankAccount ::= SEQUENCE OF {
       accountNumber OCTET STRING,
       accountName OCTET STRING,
       accountType AccountType,
       balance REAL
     }

     AccountType ::= ENUM {
       checking (0),
       savings (1)
     }

 

Given an instance of BankAccountSet with two elements, the path to the balance of each bank account in the set is given by the following expression:

/SET/SEQ/REAL

Individual child elements can be accessed by explicitly mentioning the index of the item relative to its parent. For example, the second bank account in the set can be accessed as follows:

/SET/SEQ[1]

Node names in DER paths are constrained to the following:

• UniversalDERTag tag names
• ApplicationDERTag.TAG_NAME
• ContextDERTag.TAG_NAME

See Also:

DERParser

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
(package private) static class	DERPath.Node DER path node encapsulates the path name and its location among other children that share a common parent.

Field Summary

Fields

Modifier and Type	Field and Description
private static int	HASH_CODE_SEED hash code seed.
private static Pattern	NODE_PATTERN General pattern for DER path nodes.
private Deque<DERPath.Node>	nodeStack Describes the path as a FIFO set of nodes.
static String	PATH_SEPARATOR Separates nodes in a path specification.

Constructor Summary

Constructors

Constructor and Description
DERPath() Creates an empty path specification.
DERPath(DERPath path) Copy constructor.
DERPath(String pathSpec) Creates a path specification from its string representation.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object o)
int	getSize() Gets the number of nodes in the path.
int	hashCode()
boolean	isEmpty() Determines whether the path contains any nodes.
String	peekNode() Examines the last node in the path without removing it.
String	popNode() Removes the last node in the path.
DERPath	pushNode(String name) Appends a node to the path.
DERPath	pushNode(String name, int index) Appends a node to the path with the given child index.
(package private) static DERPath.Node	toNode(String node) Converts a string representation of a node into a DERPath.Node object.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

PATH_SEPARATOR

public static final String PATH_SEPARATOR

Separates nodes in a path specification.

See Also:

Constant Field Values

NODE_PATTERN

private static final Pattern NODE_PATTERN

General pattern for DER path nodes.

HASH_CODE_SEED

private static final int HASH_CODE_SEED

hash code seed.

See Also:

Constant Field Values

nodeStack

private final Deque<DERPath.Node> nodeStack

Describes the path as a FIFO set of nodes.

Constructor Detail

DERPath

public DERPath()

Creates an empty path specification.

DERPath

public DERPath(DERPath path)

Copy constructor.

Parameters:

path - to read nodes from

DERPath

public DERPath(String pathSpec)

Creates a path specification from its string representation.

Parameters:

pathSpec - string representation of a path, e.g. /SEQ[1]/CHOICE.

Method Detail

pushNode

public DERPath pushNode(String name)

Appends a node to the path.

Parameters:

name - of the path element to add

Returns:

This instance with new node appended.

pushNode

public DERPath pushNode(String name,
                        int index)

Appends a node to the path with the given child index.

Parameters:

name - of the path element to add

index - child index

Returns:

This instance with new node appended.

peekNode

public String peekNode()

Examines the last node in the path without removing it.

Returns:

last node in the path or null if no nodes remain

popNode

public String popNode()

Removes the last node in the path.

Returns:

last node in the path or null if no more nodes remain.

getSize

public int getSize()

Gets the number of nodes in the path.

Returns:

node count.

isEmpty

public boolean isEmpty()

Determines whether the path contains any nodes.

Returns:

True if path contains 0 nodes, false otherwise.

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

toNode

static DERPath.Node toNode(String node)

Converts a string representation of a node into a DERPath.Node object.

Parameters:

node - String representation of node.

Returns:

Node corresponding to given string representation.

Throws:

IllegalArgumentException - for an invalid node name.