如何将 XML 文件中的 x 和 y 坐标解析为 Java 中的 Point2D 数组？

Question

I'm currently facing the problem that I want to feed the x and y coordinates from an XML into Java and I'm not sure how to connect the individual coordinate pairs (x and y) to points and in what form of array I should store them? The number of points is not predefined so I guess I should use an ArrayList?. Further, coordinates can also be integers sometimes (not like in the example below). My question is how to include reading into the array directly into parsing the XML file. Below are some first code fragments I tried..

The XML File looks like this:

<?xml version="1.0" encoding="UTF-8" standalone="no"?><Room><ID>Test</ID><corners><corner><x>400.3</x><y>997.2</y></corner><corner><x>400.3</x><y>833.1</y></corner><corner><x>509.9</x><y>833.1</y></corner><corner><x>509.9</x><y>700.0</y></corner>...<corner><x>1012.1</x><y>500.8</y></corner><corner><x>1012.1</x><y>900.2</y></corner><corner><x>902.0</x><y>900.2</y></corner><corner><x>902.0</x><y>997.2</y></corner></corners></Room>

My XMLParser class looks like this:

package parser;

import data.Room;
import parser.exc.XMLTransfererException;

import org.jdom2.Document;
import org.jdom2.Element;
import org.jdom2.JDOMException;
import org.jdom2.filter.ElementFilter;
import org.jdom2.input.SAXBuilder;
import org.jdom2.input.sax.XMLReaders
import org.jdom2.util.IteratorIterable;

import java.io.IOException;
import java.nio.file.Path;
import java.nio.file.Paths;


public class XMLTransferer implements IXMLTransferer {

final String dtdName = "DataModel.dtd";
final String dtdPath = "../File_Processing_Component/Model";
final String dtdFilename = String.format("%s/%s", dtdPath, dtdName);

final String xmlDoctypeRootElementName ="Raum";
boolean isValid;

SAXBuilder builder = new SAXBuilder(XMLReaders.NONVALIDATING);
Document doc = builder.build(new File(xmlFilename));

doc.setDocType(new DocType(xmlDoctypeRootElementName, dtdFilename));
String xmlString = new XMLOutputter().outputString(doc);

SAXBuilder validationBuilder = new SAXBuilder(XMLReaders.DTDVALIDATING);

@Override
public Room readFromFile(String dtdPath)
    throws XMLTransfererException {
try (doc = validationBuilder.build(new StringReader(xmlString));)
isValid = true;
} catch (JDOMException jdEx) {
// ...
isValid = false;
}
if (isValid) 
try {  IteratorIterable<Element> iter = root.getDescendants(new ElementFilter("corner"));
while (iter.hasNext()) {
    Element elem = iter.next();
    Element childX = elem.getChild("x");
    array.getPoints().add(Double.parseDouble(childX.getText()));
    Element childY = elem.getChild("y");
    array.getPoints().add(Double.parseDouble(childY.getText()));
}
}
catch (IOException | JDOMException x) {
x.printStackTrace();
}
System.out.println(array);
}
}

As you can think this is far beyond complete, however while searching an answer I don't find a way how to manage this properly. Help much appreciated!

Answer 1

try with following solution,

declare the two dimensional array list as follows,

List<List<Double>> listCoordinate = new ArrayList<List<Double>>();

add the coordinate values pare (x and y) as a list into listCoordinate,

listCoordinate.add(Arrays.asList(Double.parseDouble(childX.getText()), Double.parseDouble(childY.getText()));