org.nsdl.mptstore.rdf
Interface Node

All Known Subinterfaces:

ObjectNode, PredicateNode, SubjectNode

All Known Implementing Classes:

Literal, URIReference

public interface Node

Common interface for all RDF subjects, predicates, and objects.

Author:

cwilper@cs.cornell.edu

Method Summary

boolean	equals(java.lang.Object obj) Tell whether this Node should be considered equivalent to the given object.
java.lang.String	getValue() Get the lexical value of the node.
int	hashCode() Return a hash code for this node.
java.lang.String	toString() Get an N-Triples string representing this node.

Method Detail

getValue

java.lang.String getValue()

Get the lexical value of the node.

The lexical value of a URIReference node is the URI as a string.

The lexical value of a Literal node is a string representation of the value, and does not include the language or data type, if any.

Returns:

the lexical value, never null.

toString

java.lang.String toString()

Get an N-Triples string representing this node.

For URIReference nodes, this is <$uri>.

For Literal nodes, this is one of the following:

• "$value"
• "$value"@$lang
• "$value"^^<$datatypeURI>

Note:

• The returned string will consist of only 7-bit ASCII characters.
• The $value part will be escaped according to the rules set out by the N-Triples format.

Overrides:

toString in class java.lang.Object

Returns:

the N-Triples representation of the node.

See Also:

RDF Test Cases, Section 3: N-Triples

equals

boolean equals(java.lang.Object obj)

Tell whether this Node should be considered equivalent to the given object.

A URIReference node is equal to the given object if all of the following conditions are met:

• obj != null
• obj instanceof URIReference
• obj.getURI().equals(this.getURI())

A Literal node is equal to the given object if all of the following conditions are met:

• obj != null
• obj instanceof Literal
• obj.getValue().equals(this.getValue())
• The given literal's language (or null) is equal to this literal's language (or null).
• The given literal's datatype (or null) is equal to this literal's datatype (or null).

Overrides:

equals in class java.lang.Object

Parameters:

obj - the object to compare to this one.

Returns:

true if the objects are equal according to the rules above.

hashCode

int hashCode()

Return a hash code for this node.

The hash code of a URIReference is the hash code of getURI(). The hash code of a Literal is the hash code of getValue().

Overrides:

hashCode in class java.lang.Object

Returns:

the hash code.