org.nees.metadata.util
Class HashIdFactory

java.lang.Object
  org.nees.metadata.util.IdFactory
      org.nees.metadata.util.EncodedIdFactory
          org.nees.metadata.util.HexIdFactory
              org.nees.metadata.util.HashIdFactory

public class HashIdFactory

extends HexIdFactory

Generates ID's whose local parts are hashes of strings. This is to facilitate using arbitrary strings as local parts even if they do not conform to the subset of XML nmtoken supported by NMDS.

For instance this code:

 HashIdFactory hif = new HashIdFactory();
 hif.setPrefix("x");
 hif.setDigestAlgorithm("SHA-1");
 Identifier id = hif.newId("/C=US/O=National Computational Science Alliance/CN=Joseph M. Futrelle");");
 System.out.println(id.getLocalPart());
 

Will produce the following output:

x.5e4eff87074b049d51efd24197626b8fbaa2fc3f

Field Summary

java.lang.String

DEFAULT_DIGEST_ALGORITHM the default hash algorithm is SHA-1

Fields inherited from class org.nees.metadata.util.EncodedIdFactory

DEFAULT_STRING_ENCODING

Constructor Summary

HashIdFactory()

HashIdFactory(java.lang.String namespaceURI)
Creates a factory that produces Identifiers in a given namespace.

HashIdFactory(java.lang.String namespaceURI, java.lang.String prefix)

Method Summary

byte[]	decode(java.lang.String encoded) Subclasses implement this for specific decoding behavior.
java.lang.String	getDefaultPrefix()
java.lang.String	getDigestAlgorithm()
Identifier	newId(java.lang.String localString) Hashes the local string, appends a prefix, and uses that as the local part of the ID.
Identifier	newId(java.lang.String namespaceURI, java.lang.String localString) Hashes the local string, appends a prefix, and uses that as the local part of the ID.
void	setDigestAlgorithm(java.lang.String da)

Methods inherited from class org.nees.metadata.util.HexIdFactory

encode

Methods inherited from class org.nees.metadata.util.EncodedIdFactory

decodeToOctets, decodeToString, decodeToString, getPrefix, getStringEncoding, newId, newId, setPrefix, setStringEncoding

Methods inherited from class org.nees.metadata.util.IdFactory

getFactory, getFactory, getNamespaceURI, newId, newIdPromise, setNamespaceURI

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_DIGEST_ALGORITHM

public final java.lang.String DEFAULT_DIGEST_ALGORITHM

the default hash algorithm is SHA-1

See Also:

Constant Field Values

Constructor Detail

HashIdFactory

public HashIdFactory()

HashIdFactory

public HashIdFactory(java.lang.String namespaceURI)

Creates a factory that produces Identifiers in a given namespace.

Parameters:

namespaceURI - the namespace URI

HashIdFactory

public HashIdFactory(java.lang.String namespaceURI,
                     java.lang.String prefix)

Parameters:

namespaceURI - the namespace URI

prefix - the prefix to append to the local part

Method Detail

setDigestAlgorithm

public void setDigestAlgorithm(java.lang.String da)
                        throws java.security.NoSuchAlgorithmException

Parameters:

da - digest algorithm

Throws:

java.security.NoSuchAlgorithmException

getDigestAlgorithm

public java.lang.String getDigestAlgorithm()

Returns:

the digest algorithm

newId

public Identifier newId(java.lang.String localString)

Hashes the local string, appends a prefix, and uses that as the local part of the ID. Uses the namespace URI set for this factory instance.

Overrides:

newId in class EncodedIdFactory

Parameters:

localString - a string to hash and turn into a local part.

newId

public Identifier newId(java.lang.String namespaceURI,
                        java.lang.String localString)

Hashes the local string, appends a prefix, and uses that as the local part of the ID.

Overrides:

newId in class EncodedIdFactory

Parameters:

namespaceURI - the namespace URI to use.

localString - a string to hash and turn into a local part.

getDefaultPrefix

public java.lang.String getDefaultPrefix()

Overrides:

getDefaultPrefix in class HexIdFactory

decode

public byte[] decode(java.lang.String encoded)
              throws EncodingException

Description copied from class: EncodedIdFactory

Subclasses implement this for specific decoding behavior. Throw EncodingException if there's a problem.

Overrides:

decode in class HexIdFactory

Throws:

EncodingException