starmap.FileLoader.java Source code

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Here is the source code for starmap.FileLoader.java

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/*
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package starmap;

import java.io.InputStream;
import java.util.ArrayList;
import org.jdom2.Document;
import org.jdom2.Element;
import org.jdom2.input.SAXBuilder;

/**
 * A static class that reads a set of stars and constellations from a file
 * @author John Brink
 */
public class FileLoader {
    private static ArrayList<Star> stars = null;
    private static ArrayList<Constellation> constellations = null;

    public static ArrayList<Star> getStars() {
        if (stars == null) {
            stars = new ArrayList<>();

            // Find all the stars
            try {
                InputStream istream = FileLoader.class.getResourceAsStream("/starmap/resources/stars.xml");
                SAXBuilder builder = new SAXBuilder();
                Document doc = (Document) builder.build(istream);
                Element root = doc.getRootElement();

                System.out.printf("Parsing in %d stars\n", root.getChildren().size());

                for (Element node : root.getChildren()) {
                    Star newStar = Star.deserialize(node);
                    stars.add(newStar);
                    //System.out.printf("Parsed a star called %s\n", newStar.toString());
                }

                // Root element is "xml"
                // Convert each child into Star object
            } catch (Exception e) {
                System.out.printf("%s error reading Stars XML file: %s\n", e.getClass().getName(), e.getMessage());
            }
        }

        return stars;
    }

    public static ArrayList<Constellation> getConstellations() {
        if (constellations == null) {
            if (stars == null)
                getStars();

            constellations = new ArrayList<>();

            // Build the constellations
            try {
                InputStream istream = FileLoader.class.getResourceAsStream("/starmap/resources/constellations.xml");
                SAXBuilder builder = new SAXBuilder();
                Document doc = (Document) builder.build(istream);
                Element root = doc.getRootElement();

                for (Element node : root.getChildren()) {
                    Constellation newConst = Constellation.deserialize(node, stars);
                    constellations.add(newConst);
                    //System.out.printf("Parsed a constellation called %s\n", newConst.toString());
                }
            } catch (Exception e) {
                System.out.printf("%s error reading Constellations XML file: %s\n", e.getClass().getName(),
                        e.getMessage());
            }
        }

        return constellations;
    }

    public static String getAttribute(Element elem, String name, String defaultValue) {
        String str = elem.getChildTextTrim(name);
        if (str == null)
            return defaultValue;
        return str;
    }
}