HypericAckProcessor.java 文件源码

/**
 * <p>parseHypericAlerts</p>
 *
 * @param reader a {@link java.io.Reader} object.
 * @return a {@link java.util.List} object.
 * @throws javax.xml.bind.JAXBException if any.
 * @throws javax.xml.stream.XMLStreamException if any.
 */
public static List<HypericAlertStatus> parseHypericAlerts(Reader reader) throws JAXBException, XMLStreamException {
    List<HypericAlertStatus> retval = new ArrayList<HypericAlertStatus>();

    // Instantiate a JAXB context to parse the alert status
    JAXBContext context = JAXBContext.newInstance(new Class[] { HypericAlertStatuses.class, HypericAlertStatus.class });
    XMLInputFactory xmlif = XMLInputFactory.newInstance();
    XMLEventReader xmler = xmlif.createXMLEventReader(reader);
    EventFilter filter = new EventFilter() {
        public boolean accept(XMLEvent event) {
            return event.isStartElement();
        }
    };
    XMLEventReader xmlfer = xmlif.createFilteredReader(xmler, filter);
    // Read up until the beginning of the root element
    StartElement startElement = (StartElement)xmlfer.nextEvent();
    // Fetch the root element name for {@link HypericAlertStatus} objects
    String rootElementName = context.createJAXBIntrospector().getElementName(new HypericAlertStatuses()).getLocalPart();
    if (rootElementName.equals(startElement.getName().getLocalPart())) {
        Unmarshaller unmarshaller = context.createUnmarshaller();
        // Use StAX to pull parse the incoming alert statuses
        while (xmlfer.peek() != null) {
            Object object = unmarshaller.unmarshal(xmler);
            if (object instanceof HypericAlertStatus) {
                HypericAlertStatus alertStatus = (HypericAlertStatus)object;
                retval.add(alertStatus);
            }
        }
    } else {
        // Try to pull in the HTTP response to give the user a better idea of what went wrong
        StringBuffer errorContent = new StringBuffer();
        LineNumberReader lineReader = new LineNumberReader(reader);
        try {
            String line;
            while (true) {
                line = lineReader.readLine();
                if (line == null) {
                    break;
                } else {
                    errorContent.append(line.trim());
                }
            }
        } catch (IOException e) {
            errorContent.append("Exception while trying to print out message content: " + e.getMessage());
        }

        // Throw an exception and include the erroneous HTTP response in the exception text
        throw new JAXBException("Found wrong root element in Hyperic XML document, expected: \"" + rootElementName + "\", found \"" + startElement.getName().getLocalPart() + "\"\n" + 
                                errorContent.toString());
    }
    return retval;
}