Package org.apache.jena.graph

Class Node

java.lang.Object
org.apache.jena.graph.Node
All Implemented Interfaces:
Serializable
Direct Known Subclasses:
Node_Concrete, Node_Ext, Node_Fluid, Node_Graph, Node_Triple
public abstract class Node extends Object implements Serializable
A Node has five subtypes: Node_Blank, Node_Anon, Node_URI, Node_Variable, and Node_ANY. Nodes are only constructed by the node factory methods, and they will attempt to re-use existing nodes with the same label if they are recent enough.
See Also:

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static class 
    Node.NotLiteral
    Exception thrown if a literal-access operation is attempted on a non-literal node.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final Node
    ANY
    The canonical instance of Node_ANY.

  • Method Summary

    Modifier and Type
    Method
    Description
    abstract boolean
    equals(Object o)
    Nodes only equal other Nodes that have equal labels.
    BlankNodeId
    getBlankNodeId()
    get the blank node id if the node is blank, otherwise die horribly
    String
    getBlankNodeLabel()
    Answer the label of this blank node or throw an UnsupportedOperationException if it's not blank.
    Graph
    getGraph()
    Get the graph for a graph term (N3 formula), otherwise die horribly
    Object
    getIndexingValue()
    Answer the object which is the index value for this Node.
    LiteralLabel
    getLiteral()
    Answer the literal value of a literal node, or throw an UnsupportedOperationException if it's not a literal node
    RDFDatatype
    getLiteralDatatype()
    Answer the RDF datatype object of this node's literal value, if it is a literal; otherwise die horribly.
    String
    getLiteralDatatypeURI()
    Answer the data-type URI of this node's literal value, if it is a literal; otherwise die horribly.
    boolean
    getLiteralIsXML()
     
    String
    getLiteralLanguage()
    Answer the language of this node's literal value, if it is a literal; otherwise die horribly.
    String
    getLiteralLexicalForm()
    Answer the lexical form of this node's literal value, if it is a literal; otherwise die horribly.
    Object
    getLiteralValue()
    Answer the value of this node's literal value, if it is a literal; otherwise die horribly.
    String
    getLocalName()
    get the localname part of this node if it's a URI node, else die horribly
    String
    getName()
    get a variable nodes name, otherwise die horribly
    String
    getNameSpace()
    get the namespace part of this node if it's a URI node, else die horribly
    Triple
    getTriple()
    Get the triple for a triple term (embedded triple), otherwise die horribly
    String
    getURI()
    get the URI of this node if it has one, else die horribly
    int
    hashCode()
     
    boolean
    hasURI(String uri)
    answer true iff this node is a URI node with the given URI
    boolean
    isBlank()
    Answer true iff this node is a blank node [subclasses override]
    abstract boolean
    isConcrete()
    Answer true iff this node is concrete, ie not variable, ie URI, blank, or literal.
    boolean
    isExt()
    Extension node.
    boolean
    isLiteral()
    Answer true iff this node is a literal node [subclasses override]
    boolean
    isNodeGraph()
    Answer true iff this node is an "graph node" (N3 formula).
    boolean
    isNodeTriple()
    Answer true iff this node is an "triple node" (RDF-star)
    boolean
    isURI()
    Answer true iff this node is a URI node [subclasses override]
    boolean
    isVariable()
    Answer true iff this node is a variable node - subclasses override
    boolean
    matches(Node other)
    Answer true iff this node accepts the other one as a match.
    boolean
    sameValueAs(Object o)
    Test that two nodes are semantically equivalent.
    String
    toString()
    Answer a human-readable representation of this Node.
    String
    toString(boolean quoting)
    Answer a human-readable representation of this Node where literals are quoted according to quoting but URIs are not compressed.
    String
    toString(PrefixMapping pm)
    Answer a human-readable representation of the Node, quoting literals and compressing URIs.
    String
    toString(PrefixMapping pm, boolean quoting)
    Answer a human readable representation of this Node, quoting literals if specified, and compressing URIs using the prefix mapping supplied.
    abstract Object
    visitWith(NodeVisitor v)
    Visit a Node and dispatch on it to the appropriate method from the NodeVisitor v.

    Methods inherited from class java.lang.Object

    getClass, notify, notifyAll, wait, wait, wait

  • Field Details

    • ANY

      public static final Node ANY
      The canonical instance of Node_ANY. No other instances are required.

  • Method Details

    • visitWith

      public abstract Object visitWith(NodeVisitor v)
      Visit a Node and dispatch on it to the appropriate method from the NodeVisitor v.
      Parameters:
      v - the visitor to apply to the node
      Returns:
      the value returned by the applied method

    • isConcrete

      public abstract boolean isConcrete()
      Answer true iff this node is concrete, ie not variable, ie URI, blank, or literal.

    • isLiteral

      public boolean isLiteral()
      Answer true iff this node is a literal node [subclasses override]

    • isBlank

      public boolean isBlank()
      Answer true iff this node is a blank node [subclasses override]

    • isURI

      public boolean isURI()
      Answer true iff this node is a URI node [subclasses override]

    • isVariable

      public boolean isVariable()
      Answer true iff this node is a variable node - subclasses override

    • isNodeTriple

      public boolean isNodeTriple()
      Answer true iff this node is an "triple node" (RDF-star)

    • isNodeGraph

      public boolean isNodeGraph()
      Answer true iff this node is an "graph node" (N3 formula). This is not related to named graphs.

    • isExt

      public boolean isExt()
      Extension node. Typically used in data structures based on triples.

    • getBlankNodeId

      public BlankNodeId getBlankNodeId()
      get the blank node id if the node is blank, otherwise die horribly

    • getBlankNodeLabel

      public String getBlankNodeLabel()
      Answer the label of this blank node or throw an UnsupportedOperationException if it's not blank.

    • getLiteral

      public LiteralLabel getLiteral()
      Answer the literal value of a literal node, or throw an UnsupportedOperationException if it's not a literal node

    • getLiteralValue

      public Object getLiteralValue()
      Answer the value of this node's literal value, if it is a literal; otherwise die horribly.

    • getLiteralLexicalForm

      public String getLiteralLexicalForm()
      Answer the lexical form of this node's literal value, if it is a literal; otherwise die horribly.

    • getLiteralLanguage

      public String getLiteralLanguage()
      Answer the language of this node's literal value, if it is a literal; otherwise die horribly.

    • getLiteralDatatypeURI

      public String getLiteralDatatypeURI()
      Answer the data-type URI of this node's literal value, if it is a literal; otherwise die horribly.

    • getLiteralDatatype

      public RDFDatatype getLiteralDatatype()
      Answer the RDF datatype object of this node's literal value, if it is a literal; otherwise die horribly.

    • getLiteralIsXML

      public boolean getLiteralIsXML()

    • getIndexingValue

      public Object getIndexingValue()
      Answer the object which is the index value for this Node. The default is this Node itself; overridden in Node_Literal for literal indexing purposes. Only concrete nodes should use this method.

    • getURI

      public String getURI()
      get the URI of this node if it has one, else die horribly

    • getNameSpace

      public String getNameSpace()
      get the namespace part of this node if it's a URI node, else die horribly

    • getLocalName

      public String getLocalName()
      get the localname part of this node if it's a URI node, else die horribly

    • getName

      public String getName()
      get a variable nodes name, otherwise die horribly

    • getTriple

      public Triple getTriple()
      Get the triple for a triple term (embedded triple), otherwise die horribly

    • getGraph

      public Graph getGraph()
      Get the graph for a graph term (N3 formula), otherwise die horribly

    • hasURI

      public boolean hasURI(String uri)
      answer true iff this node is a URI node with the given URI

    • equals

      public abstract boolean equals(Object o)
      Nodes only equal other Nodes that have equal labels.
      Overrides:
      equals in class Object

    • sameValueAs

      public boolean sameValueAs(Object o)
      Test that two nodes are semantically equivalent. In some cases this may be the same as equals, in others equals is stricter. For example, two xsd:int literals with the same value but different lexical form are semantically equivalent but distinguished by the java equals function.

      Default implementation is to use equals, subclasses should override this.

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • matches

      public boolean matches(Node other)
      Answer true iff this node accepts the other one as a match. The default is an equality test; it is over-ridden in subclasses to provide the appropriate semantics for literals, ANY, and variables.
      Parameters:
      other - a node to test for matching
      Returns:
      true iff this node accepts the other as a match

    • toString

      public String toString()
      Answer a human-readable representation of this Node. It will not compress URIs, nor quote literals (because at the moment too many places use toString() for something machine-oriented).
      Overrides:
      toString in class Object

    • toString

      public String toString(boolean quoting)
      Answer a human-readable representation of this Node where literals are quoted according to quoting but URIs are not compressed.

    • toString

      public String toString(PrefixMapping pm)
      Answer a human-readable representation of the Node, quoting literals and compressing URIs.

    • toString

      public String toString(PrefixMapping pm, boolean quoting)
      Answer a human readable representation of this Node, quoting literals if specified, and compressing URIs using the prefix mapping supplied.