org.linkeddatafragments.fragments.tpf

Interface ITriplePatternElement<ConstantTermType,NamedVarType,AnonVarType>

Type Parameters:

ConstantTermType - type for representing constants in triple patterns (i.e., URIs and literals)

NamedVarType - type for representing named variables in triple patterns

AnonVarType - type for representing anonymous variables in triple patterns (i.e., variables denoted by a blank node)

All Known Implementing Classes:

TriplePatternElementFactory.AnonymousVariable, TriplePatternElementFactory.ConstantRDFTerm, TriplePatternElementFactory.NamedVariable, TriplePatternElementFactory.SpecificVariable, TriplePatternElementFactory.UnspecifiedVariable, TriplePatternElementFactory.Variable

public interface ITriplePatternElement<ConstantTermType,NamedVarType,AnonVarType>

Represents an element of a triple pattern (i.e., subject, predicate, object).

Author:

Olaf Hartig

Method Summary

Modifier and Type	Method and Description
AnonVarType	asAnonymousVariable() Returns a representation of this element as a blank node (assuming it is a specific, but non-named variable).
ConstantTermType	asConstantTerm() Returns a representation of this element as a constant RDF term (i.e., a URI or a literal).
NamedVarType	asNamedVariable() Returns a representation of this element as a named variable (assuming it is a specific variable that has a name).
boolean	isAnonymousVariable() Returns true if this element is a specific variable that does not have a name (i.e., it is denoted by a blank node), and false if either it is not a specific variable or it is a specific variable that has a name.
boolean	isNamedVariable() Returns true if this element is a specific variable that has a name (i.e., it is denoted by a string that begins with a question mark), and false if either it is not a specific variable or it is a specific variable that is denoted by a blank node.
boolean	isSpecificVariable() Returns true if this element is a specific variable, and false if either it is not a variable (but a URI or literal) or it is some variable that is not specified.
boolean	isVariable() Returns true if this element is a variable (specific or unspecified).

Method Detail

isVariable

boolean isVariable()

Returns true if this element is a variable (specific or unspecified).

Returns:

isSpecificVariable

boolean isSpecificVariable()

Returns true if this element is a specific variable, and false if either it is not a variable (but a URI or literal) or it is some variable that is not specified. The latter (unspecified variables) is possible because when a client requests a triple pattern fragment, it may omit triple pattern related parameters.

Returns:

isNamedVariable

boolean isNamedVariable()

Returns true if this element is a specific variable that has a name (i.e., it is denoted by a string that begins with a question mark), and false if either it is not a specific variable or it is a specific variable that is denoted by a blank node. If this element is a specific variable that has a name (that is, this method returns true), the named variable can be obtained by the method asNamedVariable().

Returns:

asNamedVariable

NamedVarType asNamedVariable()
                      throws UnsupportedOperationException

Returns a representation of this element as a named variable (assuming it is a specific variable that has a name).

Returns:

Throws:

UnsupportedOperationException - If this element is not a specific variable that has a name (i.e., if isNamedVariable() returns false).

isAnonymousVariable

boolean isAnonymousVariable()

Returns true if this element is a specific variable that does not have a name (i.e., it is denoted by a blank node), and false if either it is not a specific variable or it is a specific variable that has a name. If this element is a specific variable denoted by a blank node (that is, this method returns true), the blank node can be obtained by the method asAnonymousVariable().

Returns:

asAnonymousVariable

AnonVarType asAnonymousVariable()
                         throws UnsupportedOperationException

Returns a representation of this element as a blank node (assuming it is a specific, but non-named variable).

Returns:

Throws:

UnsupportedOperationException - If this element is not a specific anonymous variable (i.e., if isAnonymousVariable() returns false).

asConstantTerm

ConstantTermType asConstantTerm()
                         throws UnsupportedOperationException

Returns a representation of this element as a constant RDF term (i.e., a URI or a literal).

Returns:

Throws:

UnsupportedOperationException - If this element is not a constant RDF term but a variable (i.e., if isVariable() returns true).