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Difference between revisions of "XDI4j Tutorial 2"

(Serialization)
 
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== Serialization ==
 
== Serialization ==
  
This example app shows how to output a graph in different serialization formats.
+
'''Example Code:'''
  
 
<pre>
 
<pre>
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// let's create a simple graph
 
// let's create a simple graph
  
graph.createStatement(new XRI3Segment("=markus"), new XRI3Segment("+name"), "Markus");
+
graph.createStatement(new XRI3Segment("=alice"), new XRI3Segment("+name"), "Alice X.");
graph.createStatement(new XRI3Segment("=markus"), new XRI3Segment("+friend"), new XRI3Segment("=giovanni"));
+
graph.createStatement(new XRI3Segment("=alice"), new XRI3Segment("+friend"), new XRI3Segment("=bob"));
  
 
// output the graph in X3 Simple and XDI/XML
 
// output the graph in X3 Simple and XDI/XML
Line 51: Line 51:
  
 
== Deserialization ==
 
== Deserialization ==
 +
 +
'''Example Code:'''
  
 
<pre>
 
<pre>
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// read a graph from file
 
// read a graph from file
  
File file;
+
File file = new File("test.graph");
XDIReader reader;
+
XDIReader reader = XDIReaderRegistry.getAuto();
 
 
file = new File("test.graph");
 
reader = XDIReaderRegistry.getAuto();
 
 
 
reader.read(graph, new FileInputStream(file), null);
 
reader.read(graph, new FileInputStream(file), null);
 
 

Latest revision as of 08:57, 29 January 2010

{{#eclipseproject:technology.higgins|eclipse_custom_style.css}}

Higgins logo 76Wx100H.jpg

This tutorial explains how to serialize and deserialize an XDI graph in any of the XDI serialization formats.

A typical application is to read an XDI graph from a file into memory, perform a few operations on it, and then store it again to file.

Serialization

Example Code:

package org.eclipse.higgins.xdi4j.tutorial;

import org.eclipse.higgins.xdi4j.Graph;
import org.eclipse.higgins.xdi4j.GraphFactory;
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 output
 * a graph in different serialization formats.
 */
public class Tutorial2 {

	public static void main(String[] args) throws Exception {

		GraphFactory factory = MemoryGraphFactory.getInstance();
		Graph graph = factory.openGraph();

		// let's create a simple graph

		graph.createStatement(new XRI3Segment("=alice"), new XRI3Segment("+name"), "Alice X.");
		graph.createStatement(new XRI3Segment("=alice"), new XRI3Segment("+friend"), new XRI3Segment("=bob"));

		// output the graph in X3 Simple and XDI/XML

		XDIWriter writer;

		writer = XDIWriterRegistry.forFormat("X3 Simple");
		writer.write(graph, System.out, null);

		writer = XDIWriterRegistry.forFormat("XDI/XML");
		writer.write(graph, System.out, null);

		graph.close();
	}
}

Deserialization

Example Code:

package org.eclipse.higgins.xdi4j.tutorial;

import java.io.File;
import java.io.FileInputStream;

import org.eclipse.higgins.xdi4j.Graph;
import org.eclipse.higgins.xdi4j.GraphFactory;
import org.eclipse.higgins.xdi4j.impl.memory.MemoryGraphFactory;
import org.eclipse.higgins.xdi4j.io.XDIReader;
import org.eclipse.higgins.xdi4j.io.XDIReaderRegistry;
import org.eclipse.higgins.xdi4j.io.XDIWriter;
import org.eclipse.higgins.xdi4j.io.XDIWriterRegistry;

/**
 * This example app shows how to read a graph in one format
 * and store it in another.
 */
public class Tutorial2A {

	public static void main(String[] args) throws Exception {

		GraphFactory factory = MemoryGraphFactory.getInstance();
		Graph graph = factory.openGraph();

		// read a graph from file

		File file = new File("test.graph");
		XDIReader reader = XDIReaderRegistry.getAuto();
		
		reader.read(graph, new FileInputStream(file), null);
		
		// output the graph in X3 Simple

		XDIWriter writer;

		writer = XDIWriterRegistry.forFormat("X3 Simple");
		writer.write(graph, System.out, null);

		graph.close();
	}
}

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