ns2/NetReader.java

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package ns2;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
import java.util.Map;

import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;

public class NetReader {
    public static void read(String net, List<Edge> edges, Map<String, Junction> junctions) {        
        try {
            InputStream in = new FileInputStream(net);
            XMLInputFactory factory = XMLInputFactory.newInstance();
            XMLStreamReader parser = factory.createXMLStreamReader(in);
            // parse net file
            Edge edge = null;
            for (int event = parser.next(); event != XMLStreamConstants.END_DOCUMENT; event = parser.next()) {
                if (event == XMLStreamConstants.START_ELEMENT) {
                    // edge element found
                    if (parser.getLocalName().equals("edge")) {
                        String id    = "";
                        String from  = "";
                        String to    = "";
                        // parse attributes of element
                        for (int attr=0; attr < parser.getAttributeCount(); attr++) {
                            String attrName = parser.getAttributeLocalName(attr);
                            String value = parser.getAttributeValue(attr);
                            if ("id".equals(attrName)) {
                                id = value;
                            }
                            if ("from".equals(attrName)) {
                                from = value;
                            }
                            if ("to".equals(attrName)) {
                                to = value;
                            }
                            
                        }
                        // construct edge element
                        edge = new Edge(id, from, to);
                        // store edge
                        edges.add(edge);
                    }
                    if (parser.getLocalName().equals("lane")) {
                        String id      = "";
                        float xfrom    = 0;
                        float xto      = 0;
                        float yfrom    = 0;
                        float yto      = 0;
                        float length   = 0;
                        boolean hadShape = false;
                        // parse attributes of element
                        for (int attr=0; attr < parser.getAttributeCount(); attr++) {
                            String attrName = parser.getAttributeLocalName(attr);
                            String value = parser.getAttributeValue(attr);
                            if ("id".equals(attrName)) {
                                id = value;
                            }
                            if ("length".equals(attrName)) {
                                length = Float.parseFloat(value);
                            }
                            if ("shape".equals(attrName)) {
                                String[] vals = value.split("[,\\ ]"); // separate by delimiters "," and " "
                                xfrom = Float.parseFloat(vals[0]);
                                yfrom = Float.parseFloat(vals[1]);
                                xto   = Float.parseFloat(vals[2]);
                                yto   = Float.parseFloat(vals[3]);
                                hadShape = true;
                            }
                        }
                        if(!hadShape) {
                            String text   = parser.getElementText();
                            String[] vals = text.split("[,\\ ]"); // separate by delimiters "," and " "
                            xfrom = Float.parseFloat(vals[0]);
                            yfrom = Float.parseFloat(vals[1]);
                            xto   = Float.parseFloat(vals[2]);
                            yto   = Float.parseFloat(vals[3]);
                        }
                        edge.lanes.put(id, new Lane(id, xfrom, xto, yfrom, yto, length));
                    }
                    if (parser.getLocalName().equals("junction")) {
                        String id = "";
                        float x = 0;
                        float y = 0;
                        // parse attributes of element
                        for (int attr=0; attr < parser.getAttributeCount(); attr++) {
                            String attrName = parser.getAttributeLocalName(attr);
                            String value = parser.getAttributeValue(attr);
                            if ("id".equals(attrName)) {
                                id = value;
                            }
                            if ("x".equals(attrName)) {
                                x = Float.parseFloat(value);
                            }
                            if ("y".equals(attrName)) {
                                y = Float.parseFloat(value);
                            }
                        }
                        Junction junction = new Junction(id, x, y);
                        junctions.put(id, junction);
                    }
                }
            }
            parser.close();
        } catch (XMLStreamException ex) {
            System.err.println(ex);
        } catch (IOException ex) {
            System.err.println(ex);
        }
    }
}