org.dstadler.commons.xml.AbstractSimpleContentHandler Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of commons-dost Show documentation
Common utilities I find useful in many of my projects.
There is a newer version: 1.3.4
package org.dstadler.commons.xml;

import java.io.IOException;
import java.io.InputStream;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.SortedMap;
import java.util.TreeMap;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.util.EntityUtils;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;
import org.xml.sax.helpers.XMLReaderFactory;

import org.dstadler.commons.http.HttpClientWrapper;
import org.dstadler.commons.logging.jdk.LoggerFactory;

/**
 * Simple SAX Parser to handle XML data, it is usually subclassed to provide the
 * missing pieces of information to actually collect some information out of the XML data.
 *
 * @author dominik.stadler
 *
 */
public abstract class AbstractSimpleContentHandler extends DefaultHandler {
	private final static Logger log = LoggerFactory.make();

	// use TreeMap to sort by key
	protected SortedMap configs = new TreeMap<>();

	protected V currentTags = null;

	protected StringBuilder characters = new StringBuilder(100);

	public SortedMap parseContent(URL url, String user, String password, int timeoutMs) throws IOException, SAXException {
		log.info("Using the following URL for retrieving the list of elements: " + url.toString());

		try (final HttpClientWrapper httpClient = new HttpClientWrapper(user, password, timeoutMs)) {
			final HttpGet httpGet = new HttpGet(url.toURI());
			try (final CloseableHttpResponse response = httpClient.getHttpClient().execute(httpGet)) {
				int statusCode = response.getStatusLine().getStatusCode();
				if(statusCode != 200) {
					String msg = "Had HTTP StatusCode " + statusCode + " for request: " + url + ", response: " + response.getStatusLine().getReasonPhrase();
					log.warning(msg);

					throw new IOException(msg);
				}
			    HttpEntity entity = response.getEntity();

			    try {
					return parseContent(entity.getContent());
			    } finally {
				    // ensure all content is taken out to free resources
				    EntityUtils.consume(entity);
			    }
			}
		} catch (URISyntaxException e) {
			throw new IOException(e);
		}
	}

	public SortedMap parseContent(InputStream strm) throws SAXException, IOException {
		// clean up before starting parse to avoid multiple parse steps with the same object
		configs.clear();
		currentTags = null;
		characters.setLength(0);

		XMLReader parser = XMLReaderFactory.createXMLReader();

		parser.setContentHandler(this);
		parser.setErrorHandler(this);

		InputSource source = new InputSource(strm);

		adjustParser(parser);

		parser.parse(source);

		return getConfigs();
	}

	protected void adjustParser(XMLReader parser) {
	}

	@Override
	public void characters(char[] ch, int start, int length) throws SAXException {
		// combine characters for later use
		characters.append(ch, start, length);
	}

	@Override
	public void error(SAXParseException exception) throws SAXException {
		log.log(Level.SEVERE, "Error in SAX Parsing", exception);
	}

	@Override
	public void fatalError(SAXParseException exception) throws SAXException {
		log.log(Level.SEVERE, "Error in SAX Parsing", exception);
	}

	@Override
	public void warning(SAXParseException exception) throws SAXException {
		log.log(Level.WARNING, "Error in SAX Parsing", exception);
	}

	/**
	 * @return the issues
	 */
	public SortedMap getConfigs() {
		return configs;
	}
}