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Difference between revisions of "XDI4j Tutorial 1"
(New page: This example app shows how to perform basic graph operations and how to serialize a graph. <pre> package org.eclipse.higgins.xdi4j.tutorial; import org.eclipse.higgins.xdi4j.Graph; impor...) |
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| Line 1: | Line 1: | ||
| − | This example app shows how to | + | == Interfaces and classes == |
| + | |||
| + | === Graph === | ||
| + | |||
| + | org.eclipse.higgins.xdi4j.Graph; | ||
| + | |||
| + | This interface represents a whole XDI graph. | ||
| + | XDI graphs consist of subjects and statements between them. | ||
| + | Operations on the graph include creating new statements and subjects, finding and manipulating them | ||
| + | |||
| + | === Subject === | ||
| + | |||
| + | org.eclipse.higgins.xdi4j.Subject; | ||
| + | |||
| + | This interface represents a subject in an XDI graph. Methods include | ||
| + | creating and finding predicates of the subject. | ||
| + | |||
| + | === Predicate === | ||
| + | |||
| + | org.eclipse.higgins.xdi4j.Predicate; | ||
| + | |||
| + | This interface represents a predicate in an XDI graph. Methods include | ||
| + | creating and finding references, literals and inner graphs of the predicate. | ||
| + | |||
| + | === Reference === | ||
| + | |||
| + | org.eclipse.higgins.xdi4j.Reference; | ||
| + | |||
| + | This interface represents a reference in an XDI graph. | ||
| + | |||
| + | === Literal === | ||
| + | |||
| + | org.eclipse.higgins.xdi4j.Literal; | ||
| + | |||
| + | This interface represents a literal in an XDI graph. | ||
| + | |||
| + | === Statement === | ||
| + | |||
| + | org.eclipse.higgins.xdi4j.Statement; | ||
| + | |||
| + | This interface represents a statement in an XDI graph. | ||
| + | |||
| + | A statement consists of either: | ||
| + | |||
| + | * A subject (if the subject has no predicates). | ||
| + | * A subject and a predicate (if the predicate has no references or literals). | ||
| + | * A subject and a predicate and a reference. | ||
| + | * A subject and a predicate and a literal. | ||
| + | |||
| + | A statement never has BOTH an reference and a literal. | ||
| + | |||
| + | === GraphFactory === | ||
| + | |||
| + | org.eclipse.higgins.xdi4j.GraphFactory; | ||
| + | |||
| + | Graph factories exist for all implementations of the Graph interface (e.g. Memory, XML, Hibernate). They can be used to create a new XDI document, or to load an existing one. | ||
| + | |||
| + | == Example == | ||
| + | |||
| + | This example app shows how to create a new XDI document and how to perform basic graph operations on it. | ||
<pre> | <pre> | ||
| Line 14: | Line 73: | ||
/** | /** | ||
| − | * This example app shows how to | + | * This example app shows how to create a new XDI |
| − | * and how to | + | * document and how to perform basic graph operations on it. |
* | * | ||
* @author msabadello at parityinc dot not | * @author msabadello at parityinc dot not | ||
| Line 46: | Line 105: | ||
// after our graph is filled, we can output it | // after our graph is filled, we can output it | ||
| − | + | System.out.println(graph.toString()); | |
| − | + | ||
graph.close(); | graph.close(); | ||
Revision as of 16:31, 19 February 2008
Contents
Interfaces and classes
Graph
org.eclipse.higgins.xdi4j.Graph;
This interface represents a whole XDI graph. XDI graphs consist of subjects and statements between them. Operations on the graph include creating new statements and subjects, finding and manipulating them
Subject
org.eclipse.higgins.xdi4j.Subject;
This interface represents a subject in an XDI graph. Methods include creating and finding predicates of the subject.
Predicate
org.eclipse.higgins.xdi4j.Predicate;
This interface represents a predicate in an XDI graph. Methods include creating and finding references, literals and inner graphs of the predicate.
Reference
org.eclipse.higgins.xdi4j.Reference;
This interface represents a reference in an XDI graph.
Literal
org.eclipse.higgins.xdi4j.Literal;
This interface represents a literal in an XDI graph.
Statement
org.eclipse.higgins.xdi4j.Statement;
This interface represents a statement in an XDI graph.
A statement consists of either:
- A subject (if the subject has no predicates).
- A subject and a predicate (if the predicate has no references or literals).
- A subject and a predicate and a reference.
- A subject and a predicate and a literal.
A statement never has BOTH an reference and a literal.
GraphFactory
org.eclipse.higgins.xdi4j.GraphFactory;
Graph factories exist for all implementations of the Graph interface (e.g. Memory, XML, Hibernate). They can be used to create a new XDI document, or to load an existing one.
Example
This example app shows how to create a new XDI document and how to perform basic graph operations on it.
package org.eclipse.higgins.xdi4j.tutorial;
import org.eclipse.higgins.xdi4j.Graph;
import org.eclipse.higgins.xdi4j.GraphFactory;
import org.eclipse.higgins.xdi4j.Predicate;
import org.eclipse.higgins.xdi4j.Subject;
import org.eclipse.higgins.xdi4j.impl.memory.MemoryGraphFactory;
import org.eclipse.higgins.xdi4j.io.XDIWriter;
import org.eclipse.higgins.xdi4j.io.XDIWriterRegistry;
import org.eclipse.higgins.xdi4j.xri3.impl.XRI3Segment;
/**
* This example app shows how to create a new XDI
* document and how to perform basic graph operations on it.
*
* @author msabadello at parityinc dot not
*
*/
public class Tutorial1 {
public static void main(String[] args) throws Exception {
GraphFactory factory = MemoryGraphFactory.getInstance();
Graph graph = factory.openGraph();
// there are basically two ways of working with graphs
// 1) work with subjects, predicates, references and literals
Subject markus = graph.createSubject(new XRI3Segment("=markus"));
Predicate name = markus.createPredicate(new XRI3Segment("+name"));
Predicate friend = markus.createPredicate(new XRI3Segment("+friend"));
name.createLiteral("Markus");
friend.createReference(new XRI3Segment("=drummond"));
// 2) work with statements
graph.createStatement(new XRI3Segment("=markus"), new XRI3Segment("+friend"), new XRI3Segment("=giovanni"));
graph.createStatement(new XRI3Segment("=giovanni"), new XRI3Segment("+friend"), new XRI3Segment("=drummond"));
// after our graph is filled, we can output it
System.out.println(graph.toString());
graph.close();
}
}