How can I convert shapefile to geojson using worldwind?

I have created “Shapefile”:

Shapefile shapefile = new Shapefile(shpInputStream, shxInputStream,dbfInputStream, prjInputStream);
  log.debug("shapefile.getShapeType():"+shapefile.getShapeType());

And I can get the shapefile’s Bbox and featureNum:

bbox = shapefile.getBoundingRectangle();
            log.debug("bbox[0]:"+bbox[0]);
            log.debug("bbox[1]:"+bbox[1]);
            log.debug("bbox[2]:"+bbox[2]);
            log.debug("bbox[3]:"+bbox[3]);

            int featureNum = shapefile.getNumberOfRecords();
            log.debug("featureNum:"+featureNum);

But how can I convert it into geojson next step?

while (shapefile.hasNext())
{
    ShapefileRecord record = shapefile.nextRecord();

    log.debug("record.getShapeType():"+record.getShapeType());
    log.debug("record.getAttributes():"+record.getAttributes());
    log.debug("record.getAttributes().getValue("FCNAME"):"+record.getAttributes().getValue("FCNAME"));
    log.debug("record.getAttributes().getValue("FENAME"):"+record.getAttributes().getValue("FENAME"));
    log.debug("record.getAttributes().getValue("OBJECTID"):"+record.getAttributes().getValue("OBJECTID"));
    log.debug("record.getAttributes().getValue("the_geom"):"+record.getAttributes().getValue("the_geom"));
    //VecBuffer vb = record.getPointBuffer(0);

    //log.debug("vb.getLocations():"+vb.getLocations());
    //Polygon pgonAirspace = new Polygon(vb.getLocations());
    //log.debug("pgonAirspace.getLocations():"+pgonAirspace.getLocations());
    //break;
}