XmlReader.java

  1package eu.siacs.conversations.xml;
  2
  3import android.util.Log;
  4import android.util.Xml;
  5
  6import eu.siacs.conversations.Config;
  7
  8import im.conversations.android.xmpp.ExtensionFactory;
  9import im.conversations.android.xmpp.model.Extension;
 10import im.conversations.android.xmpp.model.StreamElement;
 11
 12import org.xmlpull.v1.XmlPullParser;
 13import org.xmlpull.v1.XmlPullParserException;
 14
 15import java.io.Closeable;
 16import java.io.IOException;
 17import java.io.InputStream;
 18import java.io.InputStreamReader;
 19
 20public class XmlReader implements Closeable {
 21	private final XmlPullParser parser;
 22	private InputStream is;
 23
 24	public XmlReader() {
 25		this.parser = Xml.newPullParser();
 26		try {
 27			this.parser.setFeature(XmlPullParser.FEATURE_PROCESS_NAMESPACES, true);
 28		} catch (XmlPullParserException e) {
 29			Log.d(Config.LOGTAG, "error setting namespace feature on parser");
 30		}
 31	}
 32
 33	public void setInputStream(InputStream inputStream) throws IOException {
 34		if (inputStream == null) {
 35			throw new IOException();
 36		}
 37		this.is = inputStream;
 38		try {
 39			parser.setInput(new InputStreamReader(this.is));
 40		} catch (XmlPullParserException e) {
 41			throw new IOException("error resetting parser");
 42		}
 43	}
 44
 45	public void reset() throws IOException {
 46		if (this.is == null) {
 47			throw new IOException();
 48		}
 49		try {
 50			parser.setInput(new InputStreamReader(this.is));
 51		} catch (XmlPullParserException e) {
 52			throw new IOException("error resetting parser");
 53		}
 54	}
 55
 56	@Override
 57	public void close() {
 58		this.is = null;
 59	}
 60
 61	public Tag readTag() throws IOException {
 62		try {
 63			while (this.is != null && parser.next() != XmlPullParser.END_DOCUMENT) {
 64				if (parser.getEventType() == XmlPullParser.START_TAG) {
 65					Tag tag = Tag.start(parser.getName());
 66					final String xmlns = parser.getNamespace();
 67					for (int i = 0; i < parser.getAttributeCount(); ++i) {
 68						final String prefix = parser.getAttributePrefix(i);
 69						String name;
 70						if (prefix != null && !prefix.isEmpty()) {
 71							name = prefix+":"+parser.getAttributeName(i);
 72						} else {
 73							name = parser.getAttributeName(i);
 74						}
 75						tag.setAttribute(name,parser.getAttributeValue(i));
 76					}
 77					if (xmlns != null) {
 78						tag.setAttribute("xmlns", xmlns);
 79					}
 80					return tag;
 81				} else if (parser.getEventType() == XmlPullParser.END_TAG) {
 82					return Tag.end(parser.getName());
 83				} else if (parser.getEventType() == XmlPullParser.TEXT) {
 84					return Tag.no(parser.getText());
 85				}
 86			}
 87
 88		} catch (Throwable throwable) {
 89			throw new IOException("xml parser mishandled "+throwable.getClass().getSimpleName()+"("+throwable.getMessage()+")", throwable);
 90		}
 91		return null;
 92	}
 93
 94	public <T extends StreamElement> T readElement(final Tag current, final Class<T> clazz)
 95			throws IOException {
 96		final Element element = readElement(current);
 97		if (clazz.isInstance(element)) {
 98			return clazz.cast(element);
 99		}
100		throw new IOException(
101				String.format("Read unexpected {%s}%s", element.getNamespace(), element.getName()));
102	}
103
104	public Element readElement(final Tag currentTag) throws IOException {
105		final var attributes = currentTag.getAttributes();
106		final var namespace = attributes.get("xmlns");
107		final var name = currentTag.getName();
108		final Element element = ExtensionFactory.create(name, namespace);
109		element.setAttributes(currentTag.getAttributes());
110		Tag nextTag = this.readTag();
111		if (nextTag == null) {
112			throw new IOException("interrupted mid tag");
113		}
114		if (nextTag.isNo()) {
115			element.setContent(nextTag.getName());
116			nextTag = this.readTag();
117			if (nextTag == null) {
118				throw new IOException("interrupted mid tag");
119			}
120		}
121		while (!nextTag.isEnd(element.getName())) {
122			if (!nextTag.isNo()) {
123				Element child = this.readElement(nextTag);
124				element.addChild(child);
125			}
126			nextTag = this.readTag();
127			if (nextTag == null) {
128				throw new IOException("interrupted mid tag");
129			}
130		}
131		return element;
132	}
133}