cswpersistenceservice.java

esri的ArcGIS Server超级学习模板程序（for java）

            getExtendedAttributeValue(query, CswPersistenceObject.UTILITIES_KEY));

        obj.setAttribute(CswPersistenceObject.QUERY_OVERLAP_EXTENT_KEY,
            getExtendedAttributeValue(query,
                CswPersistenceObject.QUERY_OVERLAP_EXTENT_KEY));

        return obj;
    }

    /**
     * Utility method to retrieve a {@link List} of {@link IQuery} objects.
     * This is done by making a call to {@link IPersonalizationContext}.
     *
     * @return {@link List} of {@link IQuery} objects retrieved from the data store.
     * @throws PersonalizationException Thrown if there was an exception with the
     *                         {@link IPersonalizationContext}.
     * @throws IllegalStateException Thrown if the {@link IPersonalizationContext} has not
     *                         been set.
     */
    private List<IQuery> getSavedQueries() throws PersonalizationException {
        List<IQuery> queries = new ArrayList<IQuery>();

        if (_personalizationContext == null) {
            throw new IllegalStateException("personalization context not set");
        }

        for (IQuery q : _personalizationContext.getData().getQueries()) {
            if (q.getType().equals(IQuery.Type.CATALOG)) {
                queries.add(q);
            }
        }

        return queries;
    }

    /**
     * Utility method to extract an attribute value out of the given
     * {@link IQuery} object using the given <code>key</code>.
     *
     * @param query The {@link IQuery} from which the attribute value will
     *                         be extracted.
     * @param key Key name of the attribute.
     * @return {@link String} value of the attribute.
     * @throws PersonalizationException Thrown if there was an exception with the
     *                         {@link IPersonalizationContext}.
     * @throws NullPointerException Thrown if the <code>query</code> or <code>key</code>
     *                         arguments are <code>null</code>.
     */
    @SuppressWarnings("unchecked")
    private String getExtendedAttributeValue(IQuery query, String key)
        throws PersonalizationException {
        String value = null;
        Iterator iter = null;
        AttributeType attr = null;

        if (query == null) {
            throw new NullPointerException("query cannot be null");
        }

        if (key == null) {
            throw new NullPointerException("key cannot be null");
        }

        iter = query.getQuery().getExtendedAttributes().getAttribute().iterator();

        while (iter.hasNext()) {
            attr = (AttributeType) iter.next();

            if (attr.getName().equals(key)) {
                value = attr.getValue();

                break;
            }
        }

        return value;
    }

    /**
     * Returns a {@link IQuery} object for the given {@link CswPersistenceObject}.
     *
     * <p>
     * First, all stored CS/W queries will be retrieved and then iterated over to see
     * if the given {@link CswPersistenceObject} already exists, based on the query name.
     * If it already exists, a reference to it will be returned.  If it doesn't exists,
     * a new {@link IQuery} with the appropriate attributes set will be returned.
     * </p>
     *
     * @param obj Reference to the {@link CswPersistenceObject} representation of the CS/W query.
     * @return {@link IQuery} object retrieved from the given {@link CswPersistenceObject}.
     * @throws PersonalizationException Thrown if there was an exception with the
     *                         {@link IPersonalizationContext}.
     * @throws NullPointerException Thrown if the <code>obj</code> argument is <code>null</code>.
     * @throws IllegalStateException Thrown if the {@link IPersonalizationContext} has not been set.
     */
    @SuppressWarnings("unchecked")
    private IQuery getQuery(CswPersistenceObject obj)
        throws PersonalizationException {
        IQuery iquery = null;
        CatalogQueryType catalogQuery = null;
        CatalogServiceType catalogService = null;
        AttributeCollectionType attr = null;
        ArrayList<AttributeType> persistenceAttr = null;
        SpatialFilter spatialFilter = null;
        ObjectFactory factory = null;
        List<IQuery> queries = null;

        if (obj == null) {
            throw new NullPointerException("persistence object cannot be null");
        }

        if (_personalizationContext == null) {
            throw new IllegalStateException("Personalization context not set");
        }

        queries = getSavedQueries();

        for (IQuery q : queries) {
            if (q.getName()
                     .equals(obj.getAttribute(
                            CswPersistenceObject.QUERY_NAME_KEY))) {
                iquery = q;

                LOG.debug("Updating query - ID: [" + q.getId() + "] Name: [" +
                    q.getName() + "]");

                break;
            }
        }

        // if the query was not found, create a new one
        if (iquery == null) {
            iquery = _personalizationContext.getData()
                                            .createQuery(IQuery.Type.CATALOG);
        }

        catalogQuery = (CatalogQueryType) iquery.getQuery();

        // set the query name and description
        catalogQuery.setName(obj.getAttribute(
                CswPersistenceObject.QUERY_NAME_KEY));
        catalogQuery.setDescription(obj.getAttribute(
                CswPersistenceObject.QUERY_DESCRIPTION_KEY));
        catalogQuery.setMaxResults(Integer.parseInt(obj.getAttribute(
                    CswPersistenceObject.MAX_RESULTS_KEY)));

        try {
            // create the object factory
            factory = new ObjectFactory();

            // add the extended search attributes
            attr = factory.createAttributeCollectionType();
            persistenceAttr = generatePersistenceAttributes(obj);
            attr.getAttribute().addAll(persistenceAttr);
            catalogQuery.setExtendedAttributes(attr);

            // set the catalog service
            catalogService = factory.createCatalogServiceType();
            catalogService.setId(obj.getAttribute(
                    CswPersistenceObject.CATALOG_ID_KEY));
            catalogQuery.setCatalogService(catalogService);

            // set the query filter
            spatialFilter = generateSpatialFilter(obj);
            catalogQuery.setSpatialFilter(spatialFilter);
        } catch (JAXBException ex) {
            LOG.warn("JAXBException occurred creating IQuery", ex);

            iquery = null;
        }

        return iquery;
    }

    /**
     * Utility method to convert the serialized XML representation of a CS/W
     * query to a {@link QueryType} via JAXB.
     *
     * @param xml {@link String} serialized version of the query.
     * @return {@link QueryType} object resulting in the JAXB unmarshall operation.
     * @throws PersonalizationException Thrown if there was a serialization problem.
     * @throws NullPointerException Thrown if the <code>xml</code> argument is
     *                         <code>null</code>.
     */
    private QueryType unmarshallQuery(String xml)
        throws PersonalizationException {
        JAXBContext ctx = null;
        Unmarshaller unmarshaller = null;
        QueryType queryType = null;

        if (xml == null) {
            throw new NullPointerException();
        }

        if (LOG.isDebugEnabled()) {
            LOG.debug(MessageFormat.format(
                    DEBUG_QUERY_DATA_BEFORE_UNMARSHALLING, xml));
        }

        try {
            ctx = JAXBContext.newInstance(JAXB_BEAN_PACKAGE_NAME);
            unmarshaller = ctx.createUnmarshaller();

            queryType = (QueryType) unmarshaller.unmarshal(new ByteArrayInputStream(
                        xml.getBytes()));

            return queryType;
        } catch (JAXBException ex) {
            LOG.warn("JAXBException occurred unmarshalling query xml", ex);

            LOG.debug("JAXBException occurred unmarshalling query xml: " + xml);

            throw new PersonalizationException(PersonalizationException.Code.SERIALIZATION_ERROR);
        }
    }

    /**
     * Utility method to serialize the given {@link IQuery} object
     * to it's XML representation via JAXB.
     *
     * @param query Reference to the {@link IQuery} to be serialized.
     * @return {@link String} XML query representation.
     * @throws PersonalizationException Thrown if there was a serialization problem.
     * @throws NullPointerException Thrown if the <code>query</code> argument is <code>null</code>.
     */
    private String marshallQuery(IQuery query) throws PersonalizationException {
        JAXBContext ctx = null;
        Marshaller marshaller = null;
        ByteArrayOutputStream out = null;
        byte[] data = null;

        if (query == null) {
            throw new NullPointerException("query cannot be null");
        }

        try {
            ctx = JAXBContext.newInstance(JAXB_BEAN_PACKAGE_NAME);
            marshaller = ctx.createMarshaller();

            out = new ByteArrayOutputStream();
            marshaller.marshal(query.getQuery(), out);

            data = out.toByteArray();

            if (LOG.isDebugEnabled()) {
                LOG.debug(MessageFormat.format(
                        DEBUG_QUERY_DATA_AFTER_MARSHALLING, query.getId(),
                        query.getName(), new String(data)));
            }

            return new String(data);
        } catch (JAXBException ex) {
            LOG.warn("JAXBException occurred marshalling query to xml", ex);

            throw new PersonalizationException(PersonalizationException.Code.SERIALIZATION_ERROR);
        } catch (Exception ex) {
            LOG.warn("Exception occurred marshalling query to xml", ex);

            throw new PersonalizationException(PersonalizationException.Code.SERIALIZATION_ERROR);
        }
    }
}