org.nsdl.mptstore.util
Class NTriplesUtil

java.lang.Object
  org.nsdl.mptstore.util.NTriplesUtil

public abstract class NTriplesUtil
extends java.lang.Object

Utility for parsing, validating, and printing strings in N-Triples format.

Author:

cwilper@cs.cornell.edu

Method Summary

static java.lang.String	consumeURIReference(java.io.Reader reader, int pos) Consume the next URI reference.
static int	consumeWhitespace(java.io.Reader reader, int pos) Move the reader to the first non-whitespace character and return the number of whitespaces encountered.
static java.lang.String	escapeLiteralValue(java.lang.String s) Escape a string to N-Triples literal format.
static Literal	parseLiteral(java.lang.String s) Parse an RDF literal in N-Triples format.
static Node	parseNode(java.lang.String ntNode) Parse an RDF node in N-Triples format.
static ObjectNode	parseObject(java.lang.String ntObject) Parse an RDF object in N-Triples format.
static PredicateNode	parsePredicate(java.lang.String ntPredicate) Parse an RDF predicate in N-Triples format.
static SubjectNode	parseSubject(java.lang.String ntSubject) Parse an RDF subject in N-Triples format.
static Triple	parseTriple(java.lang.String ntTriple) Parse an RDF triple in N-Triples format.
static URIReference	parseURIReference(java.lang.String s) Parse an RDF URI reference in N-Triples format.
static java.lang.String	unescapeLiteralValue(java.lang.String s) Unescape an N-Triples-escaped string.
static void	validateLanguage(java.lang.String language) Validate the given language tag according to RFC3066.

Methods inherited from class java.lang.Object

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

Method Detail

consumeURIReference

public static java.lang.String consumeURIReference(java.io.Reader reader,
                                                   int pos)
                                            throws java.io.IOException,
                                                   java.text.ParseException

Consume the next URI reference. This will advance the reader through the next '>' character.

Parameters:

reader - the reader to get characters from.

pos - the current position in the overall input.

Returns:

all characters up to an including the terminal, '>'.

Throws:

java.io.IOException - if there's an I/O error reading the input.

java.text.ParseException - if the reader is exhausted before the terminal is encountered.

consumeWhitespace

public static int consumeWhitespace(java.io.Reader reader,
                                    int pos)
                             throws java.io.IOException,
                                    java.text.ParseException

Move the reader to the first non-whitespace character and return the number of whitespaces encountered.

Parameters:

reader - the reader.

pos - the current position in the reader.

Returns:

the number of whitespaces encountered.

Throws:

java.io.IOException - if there is an error reading.

java.text.ParseException - if the first character is not a whitespace or EOF is reached before a non-whitespace char.

parseTriple

public static Triple parseTriple(java.lang.String ntTriple)
                          throws java.text.ParseException

Parse an RDF triple in N-Triples format.

Parameters:

ntTriple - the input string.

Returns:

the parsed triple.

Throws:

java.text.ParseException - if the input syntax is incorrect

See Also:

N-Triples triple syntax

parseSubject

public static SubjectNode parseSubject(java.lang.String ntSubject)
                                throws java.text.ParseException

Parse an RDF subject in N-Triples format.

Parameters:

ntSubject - the input string.

Returns:

the parsed subject.

Throws:

java.text.ParseException - if the input syntax is incorrect

See Also:

N-Triples subject syntax

parsePredicate

public static PredicateNode parsePredicate(java.lang.String ntPredicate)
                                    throws java.text.ParseException

Parse an RDF predicate in N-Triples format.

Parameters:

ntPredicate - the input string.

Returns:

the parsed predicate.

Throws:

java.text.ParseException - if the input syntax is incorrect

See Also:

N-Triples predicate syntax

parseObject

public static ObjectNode parseObject(java.lang.String ntObject)
                              throws java.text.ParseException

Parse an RDF object in N-Triples format.

Parameters:

ntObject - the input string.

Returns:

the parsed predicate.

Throws:

java.text.ParseException - if the input syntax is incorrect

See Also:

N-Triples object syntax

parseNode

public static Node parseNode(java.lang.String ntNode)
                      throws java.text.ParseException

Parse an RDF node in N-Triples format.

Parameters:

ntNode - the input string.

Returns:

the parsed node.

Throws:

java.text.ParseException - if the input syntax is incorrect

parseLiteral

public static Literal parseLiteral(java.lang.String s)
                            throws java.text.ParseException

Parse an RDF literal in N-Triples format.

Parameters:

s - the input string.

Returns:

the parsed literal.

Throws:

java.text.ParseException - if the input syntax is incorrect

parseURIReference

public static URIReference parseURIReference(java.lang.String s)
                                      throws java.text.ParseException

Parse an RDF URI reference in N-Triples format.

Parameters:

s - the input string.

Returns:

the parsed URI reference.

Throws:

java.text.ParseException - if the input syntax is incorrect

unescapeLiteralValue

public static java.lang.String unescapeLiteralValue(java.lang.String s)
                                             throws java.text.ParseException

Unescape an N-Triples-escaped string.

• All input characters are validated to be 7-bit ASCII.
• Unicode escapes (\uxxxx and \Uxxxxxxxx) are validated to be complete and legal, and are restored to the value indicated by the hexadecimal argument.
• Backslash-escaped values (\t, \r, \n, \", and \\) are restored to their original form (tab, carriage return, linefeed, quote, and backslash, respectively).

Parameters:

s - The input string.

Returns:

The unescaped string.

Throws:

java.text.ParseException - if the input syntax is incorrect

escapeLiteralValue

public static java.lang.String escapeLiteralValue(java.lang.String s)

Escape a string to N-Triples literal format.

• Unicode escaping (\uxxxx or \Uxxxxxxxx, a appropriate) will be used for all characters in the following ranges:
  • 0x0 through 0x8
  • 0xB through 0xC
  • 0xE through 0x1F
  • 0x7F through 0xFFFF
  • 0x10000 through 0x10FFFF
• Backslash escaping will be used for double quote (\"), backslash (\\), line feed (\n), carriage return (\r), and tab (\t) characters.
• All other characters will be represented as-is.

Parameters:

s - The input string.

Returns:

The escaped string.

validateLanguage

public static void validateLanguage(java.lang.String language)
                             throws java.text.ParseException

Validate the given language tag according to RFC3066. The grammar for a language tag is:

   LANGUAGE-TAG   = PRIMARY-SUBTAG ("-" SUBTAG)*
   PRIMARY-SUBTAG = 1-8(ALPHA)
   SUBTAG         = 1-8(ALPHA/DIGIT)
 

Parameters:

language - the language to validate.

Throws:

java.text.ParseException - if the language is syntactically invalid.