wfsggetfeatureresponsehandler.java

esri的ArcGIS Server超级学习模板程序（for java）

package com.esri.solutions.jitk.common.gazetteer;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

import java.util.ArrayList;
import java.util.List;


/**
 * Class responsible for parsing WFS-G GetFeature responses by extending
 * {@link DefaultHandler}.
 */
public class WfsgGetFeatureResponseHandler extends DefaultHandler {
    /**
     * {@link ArrayList} of {@link GazetteerPlace} objects parsed from
     * the WFS-G GetFeature response.
     */
    private List<GazetteerPlace> _places = null;

    /**
     * Value indicating if the current element is the SI_LocationInstance
     * element.
     */
    private boolean _isSILocationInstance = false;

    /**
     * Value indicating if the current element is the
     * SI_LocationInstance/geographicIdentifier element.
     */
    private boolean _isGeographicIdentifier = false;

    /**
     * Value indicating if the current element is the location element
     * of the SI_LocationInstance/geographicIdentifier element.
     *
     * Referenced element is gml:posList
     */
    private boolean _isPosList = false;

    /**
     * Value indicating if the current element is the location element
     * of the SI_LocationInstance/geographicIdentifier element.
     *
     * Referenced element is gml:pos
     */
    private boolean _isPos = false;

    /**
     * Value indicating if the current element is the bounded by element
     * of the WFS-G GetFeature response.
     */
    private boolean _isBoundedBy = false;

    /**
     * {@link GazetteerPlace} object that is created with each
     * new SI_LocationInstance element.
     */
    private GazetteerPlace _place = null;

    /**
     * Spatial reference ID.  Default is 4326.
     */
    private String _srsId = "4326";

    /**
     * Default no-args constructor.
     */
    public WfsgGetFeatureResponseHandler() {
        _places = new ArrayList<GazetteerPlace>();
    }

    /*
     * (non-Javadoc)
     * @see org.xml.sax.helpers.DefaultHandler#characters(char[], int, int)
     */
    public void characters(char[] ch, int start, int length)
        throws SAXException {
        if (_isSILocationInstance && _isGeographicIdentifier) {
            String name = _place.getPlaceName();

            // the characters() method is no required to give the entire text
            // node all at once.  The parser is free to split up the text node
            // and call characters() several times.  Handle this possibility.
            if (name == null) {
                name = new String(ch, start, length);
            } else {
                name += new String(ch, start, length);
            }

            _place.setPlaceName(name);
        } else if (_isSILocationInstance && _isPos) {
            String location = _place.getPlaceLocation();

            // the characters() method is no required to give the entire text
            // node all at once.  The parser is free to split up the text node
            // and call characters() several times.  Handle this possibility.
            if (location == null) {
                location = new String(ch, start, length);
            } else {
                location += new String(ch, start, length);
            }

            _place.setPlaceLocation(location);
        } else if (_isSILocationInstance && _isPosList) {
            String location = _place.getPlaceLocation();

            // the characters() method is no required to give the entire text
            // node all at once.  The parser is free to split up the text node
            // and call characters() several times.  Handle this possibility.
            if (location == null) {
                location = new String(ch, start, length);
            } else {
                location += new String(ch, start, length);
            }

            _place.setPlaceLocation(location);
        }
    }

    /*
     * (non-Javadoc)
     * @see org.xml.sax.helpers.DefaultHandler#endElement(java.lang.String, java.lang.String, java.lang.String)
     */
    public void endElement(String uri, String localName, String name)
        throws SAXException {
        if (localName.equalsIgnoreCase("SI_LocationInstance")) {
            _isSILocationInstance = false;
            _places.add(_place);
        } else if (localName.equalsIgnoreCase("geographicIdentifier")) {
            _isGeographicIdentifier = false;
        } else if (localName.equalsIgnoreCase("pos")) {
            _isPos = false;
        } else if (localName.equalsIgnoreCase("posList")) {
            _isPosList = false;
        } else if (localName.equalsIgnoreCase("boundedBy")) {
            _isBoundedBy = false;
        }
    }

    /*
     * (non-Javadoc)
     * @see org.xml.sax.helpers.DefaultHandler#startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)
     */
    public void startElement(String uri, String localName, String name,
        Attributes attributes) throws SAXException {
        if (localName.equalsIgnoreCase("SI_LocationInstance")) {
            _isSILocationInstance = true;
            _place = new GazetteerPlace();
        } else if (localName.equalsIgnoreCase("geographicIdentifier")) {
            _isGeographicIdentifier = true;
        } else if (localName.equalsIgnoreCase("pos")) {
            _isPos = true;
        } else if (localName.equalsIgnoreCase("posList")) {
            _isPosList = true;
        } else if (localName.equalsIgnoreCase("boundedBy")) {
            _isBoundedBy = true;
        } else if (localName.equalsIgnoreCase("Envelope") && _isBoundedBy) {
            _srsId = attributes.getValue("srsName");
        }
    }

    /**
     * Gets the {@link List} of {@link GazetteerPlace}.
     *
     * @return {@link List} of {@link GazetteerPlace} parsed from the WFS-G GetFeature
     *                 response.
     */
    public List<GazetteerPlace> getPlaces() {
        return _places;
    }

    /**
     * Gets the Spatial Reference ID of the WFS-G GetFeature
     * response results.
     *
     * @return Spatial Reference of the WFS-G GetFeature response results.  If no ID is
     *                 specified 4326 is the default.
     */
    public String getSrsId() {
        return _srsId;
    }
}