Jena Framework: Interface Statement

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com.hp.hpl.mesa.rdf.jena.model
Interface Statement

All Superinterfaces:: RDFNode, Resource

All Known Implementing Classes:: StatementImpl

public interface Statement
extends Resource

An RDF Statement.

A statement is also itself a resource and can be both the subject and object of other statements.

Like other resources, a statement instance tracks which model it is associated with.

This interface provides methods supporting typed literals. This means that methods are provided which will translate a built in type, or an object to an RDF Literal. This translation is done by invoking the toString() method of the object, or its built in equivalent. The reverse translation is also supported. This is built in for built in types. Factory objects, provided by the application, are used for application objects.

This interface provides methods for supporting enhanced resources. An enhanced resource is a resource to which the application has added behaviour. RDF containers are examples of enhanced resources built in to this package. Enhanced resources are supported by encapsulating a resource created by an implementation in another class which adds the extra behaviour. Factory objects are used to construct such enhanced resources.

Version:: $Name: $ $Revision: 1.4 $ $Date: 2001/09/24 12:14:00 $
Author:: bwm

Method Summary

boolean equals(java.lang.Object o)
          determine whether two statements are equal.

Alt getAlt()
          Return the object of the statement.

Bag getBag()
          Return the object of the statement.

boolean getBoolean()
          Return the object of the statement.

byte getByte()
          Return the object of the statement.

char getChar()
          Return the object of the statement.

double getDouble()
          Return the object of the statement.

float getFloat()
          Return the object of the statement.

int getInt()
          Return the object of the statement.

java.lang.String getLanguage()
          Return the language of the object of the statement

Literal getLiteral()
          Return the object of the statement.

long getLong()
          Return the object of the statement.

RDFNode getObject()
          An accessor funtion to return the object of the statement.

java.lang.Object getObject(ObjectF f)
          Return the object of the statement.

Property getPredicate()
          An accessor function to return the predicate of the statement.

Statement getProperty(Property p)
          Get a property of the object of the statement.

Resource getResource()
          Return the object of the statement.

Resource getResource(ResourceF f)
          Return the object of the statement.

Seq getSeq()
          Return the object of the statement.

short getShort()
          Return the object of the statement.

Statement getStatementProperty(Property p)
          Return a property of this statement.

java.lang.String getString()
          Return the object of the statement.

Resource getSubject()
          An accessor method to return the subject of the statements.

boolean getWellFormed()
          Return whether the Literal object is well formed XML as would result from parsing a property element with parseType="Literal"

boolean isReified()
          Determine if this statement is the subject of any statements its associated model.

Statement remove()
          Remove this statement from its associated model.

Statement set(boolean o)
          Set the object of the statement.

Statement set(char o)
          Set the object of the statement.

Statement set(double o)
          Set the object of the statement.

Statement set(float o)
          Set the object of the statement.

Statement set(long o)
          Set the object of the statement.

Statement set(java.lang.Object o)
          Set the object of the statement.

Statement set(RDFNode o)
          Set the object of the statement.

Statement set(java.lang.String o)
          Set the object of the statement.

Statement set(java.lang.String o, boolean wellFormed)
          Set the object of the statement.

Statement set(java.lang.String o, java.lang.String l)
          Set the object of the statement.

Statement set(java.lang.String o, java.lang.String l, boolean wellFormed)
          Set the object of the statement.

Methods inherited from interface com.hp.hpl.mesa.rdf.jena.model.Resource

abort, addProperty, addProperty, addProperty, addProperty, addProperty, addProperty, addProperty, addProperty, addProperty, begin, commit, getId, getLocalName, getModel, getNameSpace, getURI, hasProperty, hasProperty, hasProperty, hasProperty, hasProperty, hasProperty, hasProperty, hasProperty, hasProperty, hasProperty, isAnon, listProperties, listProperties, removeProperties, toString

Method Detail

equals

public boolean equals(java.lang.Object o)

determine whether two statements are equal.

Two statements are considered to be equal if they have the the same subject, predicate and object. A statement can only be equal to another statement object.

Specified by:: equals in interface Resource
Overrides:: equals in class java.lang.Object

Parameters:: o - the object to be compared
Returns:: true if and only if the equality condition is met.

getSubject

public Resource getSubject()

An accessor method to return the subject of the statements.

Returns:: The subject of the statement.

getPredicate

public Property getPredicate()

An accessor function to return the predicate of the statement.

Returns:: The predicate of the statement.

getObject

public RDFNode getObject()

An accessor funtion to return the object of the statement.

Returns:: Return the object of the statement.

getProperty

public Statement getProperty(Property p)
                      throws RDFException

Get a property of the object of the statement.

There is an unfortunate ambiguity here. GetProperty would normally treat the statement as a resource, and return a property about this statement. This is not what is wanted in most cases, so getProperty on a statement is defined to call getProperty on its object. If a property of the statement itself is required, getStatementProperty should be used.

If the object of the statement is not a resource, an exception is thrown.

Specified by:: getProperty in interface Resource

Parameters:: p - the property sought
Returns:: a statement representing an instance of the required property
Throws:: RDFException - Generic RDF Exception

getStatementProperty

public Statement getStatementProperty(Property p)
                               throws RDFException

Return a property of this statement.

The model associated with this statement is searched for a statement with this statement as subject and the specified property as predicate. If such a statement is found it is return. If more than one exists in the model, then it is undefined which is returned. If no such statement exists, an exception is thrown.

Parameters:: p - the property sought
Returns:: a statement representing an instance of the specified property.
Throws:: RDFException - Generic RDF exception