catalogwriter.java

电子地图服务器,搭建自己的地图服务

/* Copyright (c) 2001 - 2007 TOPP - www.openplans.org. All rights reserved.
 * This code is licensed under the GPL 2.0 license, availible at the root
 * application directory.
 */
package org.geoserver.data;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.Map;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;


/**
 * Writes the GeoServer catalog.xml file.
 * <p>
 * Usage:
 *
 * <pre>
 *         <code>
 *
 *                  Map dataStores = ...
 *                  Map nameSpaces = ...
 *
 *                  CatalogWriter writer = new CatalogWriter();
 *                  writer.dataStores( dataStores );
 *                  writer.nameSpaces( nameSpaces );
 *
 *                  File catalog = new File( &quot;.../catalog.xml&quot; );
 *                  writer.write( catalog );
 *
 *
 * </code>
 * </pre>
 *
 * </p>
 *
 * @author Justin Deoliveira, The Open Planning Project, [e-mail]
 *
 */
public class CatalogWriter {
    /**
     * The xml document
     */
    Document document;

    /**
     * Root catalog element.
     */
    Element catalog;

    public CatalogWriter() {
        try {
            DocumentBuilderFactory builderFactory = DocumentBuilderFactory
                .newInstance();
            builderFactory.setNamespaceAware(false);
            builderFactory.setValidating(false);

            document = builderFactory.newDocumentBuilder().newDocument();
            catalog = document.createElement("catalog");
            document.appendChild(catalog);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * Writes "datastore" elements to the catalog.xml file.
     *
     * @param dataStores map of id to connection parameter map
     * @param namespaces map of id to namespace prefix map
     *
     *
     */
    public void dataStores(Map /* <String,Map> */ dataStores, Map /*<String,String>*/ namespaces) {
        Element dataStoresElement = document.createElement("datastores");
        catalog.appendChild(dataStoresElement);

        for (Iterator d = dataStores.entrySet().iterator(); d.hasNext();) {
            Map.Entry dataStore = (Map.Entry) d.next();
            String id = (String) dataStore.getKey();
            Map params = (Map) dataStore.getValue();

            Element dataStoreElement = document.createElement("datastore");
            dataStoresElement.appendChild(dataStoreElement);

            // set the datastore id
            dataStoreElement.setAttribute("id", id);

            //set the namespace
            dataStoreElement.setAttribute("namespace", (String) namespaces.get(id));

            // encode hte ocnnection paramters
            Element connectionParamtersElement = document.createElement("connectionParams");
            dataStoreElement.appendChild(connectionParamtersElement);

            for (Iterator p = params.entrySet().iterator(); p.hasNext();) {
                Map.Entry param = (Map.Entry) p.next();
                String name = (String) param.getKey();
                Object value = param.getValue();

                // skip null values
                if (value == null) {
                    continue;
                }

                Element parameterElement = document.createElement("parameter");
                connectionParamtersElement.appendChild(parameterElement);

                parameterElement.setAttribute("name", name);
                parameterElement.setAttribute("value", value.toString());
            }
        }
    }

    /**
     * Writes "namespace" elements to the catalog.xml file.
     *
     * @param namespaces
     *            map of <prefix,uri>, default uri is located under the empty
     *            string key.
     *
     */
    public void namespaces(Map namespaces) {
        Element namespacesElement = document.createElement("namespaces");
        catalog.appendChild(namespacesElement);

        for (Iterator n = namespaces.entrySet().iterator(); n.hasNext();) {
            Map.Entry namespace = (Map.Entry) n.next();
            String prefix = (String) namespace.getKey();
            String uri = (String) namespace.getValue();

            // dont write out default prefix
            if ("".equals(prefix)) {
                continue;
            }

            Element namespaceElement = document.createElement("namespace");
            namespacesElement.appendChild(namespaceElement);

            namespaceElement.setAttribute("uri", uri);
            namespaceElement.setAttribute("prefix", prefix);

            // check for default
            if (uri.equals(namespaces.get(""))) {
                namespaceElement.setAttribute("default", "true");
            }
        }
    }

    /**
     * Writes "style" elements to the catalog.xml file.
     *
     * @param styles
     *            map of <id,filename>
     *
     */
    public void styles(Map styles) {
        Element stylesElement = document.createElement("styles");
        catalog.appendChild(stylesElement);

        for (Iterator s = styles.entrySet().iterator(); s.hasNext();) {
            Map.Entry style = (Map.Entry) s.next();
            String id = (String) style.getKey();
            String filename = (String) style.getValue();

            Element styleElement = document.createElement("style");
            stylesElement.appendChild(styleElement);

            styleElement.setAttribute("id", id);
            styleElement.setAttribute("filename", filename);
        }
    }

    /**
     * WRites the catalog.xml file.
     * <p>
     * This method *must* be called after any other methods.
     * </p>
     *
     * @param file
     *            The catalog.xml file.
     *
     * @throws IOException
     *             In event of a writing error.
     */
    public void write(File file) throws IOException {
        try {
            Transformer tx = TransformerFactory.newInstance().newTransformer();
            tx.setOutputProperty(OutputKeys.INDENT, "yes");
            DOMSource source = new DOMSource(document);
            StreamResult result = new StreamResult(file);

            tx.transform(source, result);
        } catch (Exception e) {
            String msg = "Could not write catalog to " + file;
            throw (IOException) new IOException(msg).initCause(e);
        }
    }
}