How to mark multiple coordinates in KML using Java?

Question

I'm working on a project that involves KML creation using Java. Currently, I'm fooling with the sample Java code from the KML example at Micromata Labs JAK Example . I tried to "extend" the code by adding multiple coordinates and getting two markers, but I could not get it to work. Can you please tell me how I can add multiple coordinates and put markers on them, and also, draw a line between the markers. Thank you for your help!

PS: I need to do this via the program. I saw sample code of them using DOM and XML, but not pure Java/JAK as such. Please guide me.

I got as far as this (updated):

kml.createAndSetDocument().withName("MyMarkers")
.createAndAddPlacemark().withName("London, UK").withOpen(Boolean.TRUE)  
.createAndSetPoint().addToCoordinates(-0.126236, 51.500152);    

kml.createAndSetDocument().withName("MyMarkers")  
.createAndAddPlacemark().withName("Somewhere near London,UK").withOpen(Boolean.TRUE)
.createAndSetPoint().addToCoordinates(-0.129800,52.70‌​0152);

But I know I'm going wrong somewhere. Please point me in the right direction.

Here is the resulting KML output:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<kml xmlns="http://www.opengis.net/kml/2.2" xmlns:gx="http://www.google.com/kml/ext/2.2" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:xal="urn:oasis:names:tc:ciq:xsdschema:xAL:2.0">
<Document>
    <name>MyMarkers</name>
    <Placemark>
        <name>Somewhere near London, UK</name>
        <open>1</open>
        <Point>
            <coordinates>-0.1298,52.700152</coordinates>
        </Point>
    </Placemark>
</Document>
</kml>

I can't seem to access the Document again to add more placemarks. How do I do it?

Answer 1

Basically, you need to do:

Document document = kml.createAndSetDocument().withName("MyMarkers");

document.createAndAddPlacemark().withName("London, UK").withOpen(Boolean.TRUE)  
    .createAndSetPoint().addToCoordinates(-0.126236, 51.500152);    

document.createAndAddPlacemark().withName("Somewhere near London,UK").withOpen(Boolean.TRUE)
    .createAndSetPoint().addToCoordinates(-0.129800,52.70‌​0152);

Previously, you were creating a new document and setting it (as the only document!) in the kml object. Therefore, only the last entry was shown.

Answer 2

To put more than one Placemark in a KML file you need a Folder or a Document

A basic <kml> element contains 0 or 1 Feature

A Feature is an abstract element that can be a Placemark .

A Container extends Feature and can be a Document or a Folder

To make a long story short, if you want multiple Placemarks, you need to include them in a Document or a Folder

<kml>
  <Document>
    <Placemark>
    </Placemark>
    ...
    <Placemark>
    </Placemark>
  </Document>
</kml>

Answer 3

The documentation is very bad.

        final Kml kml = new Kml();
        Document document = kml.createAndSetDocument();
        listForms = formDAO.getAll();
        for (Form list : listForms){
            document.createAndAddPlacemark()
            .withName(String.valueOf(list.getId()))
            .withDescription(list.toStringKML())
            .createAndSetPoint().addToCoordinates(-20.3978398, -43.5146653);
        }
        kml.setFeature(document);
        kml.marshal(new File("test.kml"));