/* 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 java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.geoserver.util.ReaderUtils;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
/**
* Reads the GeoServer catalog.xml file.
* <p>
* Usage:
*
* <pre>
* <code>
* File catalog = new File( ".../catalog.xml" );
* CatalogReader reader = new CatalogReader();
* reader.read( catalog );
* List dataStores = reader.dataStores();
* LIst nameSpaces = reader.nameSpaces();
* </code>
* </pre>
* </p>
*
* @author Justin Deoliveira, The Open Planning Project, jdeolive@openplans.org
*
*/
public class CatalogReader {
/**
* Root catalog element.
*/
Element catalog;
/**
* Parses the catalog.xml file into a DOM.
* <p>
* This method *must* be called before any other methods.
* </p>
*
* @param file The catalog.xml file.
*
* @throws IOException In event of a parser error.
*/
public void read(File file) throws IOException {
FileReader reader = new FileReader(file);
try {
catalog = ReaderUtils.parse(reader);
} finally {
reader.close();
}
}
/**
* Reads "datastore" elements from the catalog.xml file.
* <p>
* For each datastore element read, a map of the connection parameters is
* created.
* </p>
*
* @return A list of Map objects containg the datastore connection parameters.
*
* @throws Exception If error processing "datastores" element.
*/
public List /*<Map>*/ dataStores() throws Exception {
Element dataStoresElement = ReaderUtils.getChildElement(catalog, "datastores", true);
NodeList dataStoreElements = dataStoresElement.getElementsByTagName("datastore");
ArrayList dataStores = new ArrayList();
for (int i = 0; i < dataStoreElements.getLength(); i++) {
Element dataStoreElement = (Element) dataStoreElements.item(i);
try {
Map params = dataStoreParams(dataStoreElement);
dataStores.add(params);
} catch (Exception e) {
//TODO: log this
continue;
}
}
return dataStores;
}
/**
* Reads "namespace" elements from the catalog.xml file.
* <p>
* For each namespace element read, an entry of <prefix,uri> is created
* in a map. The default uri is located under the empty string key.
* </p>
*
* @return A map containing <prefix,uri> tuples.
*
* @throws Exception If error processing "namespaces" element.
*/
public Map namespaces() throws Exception {
Element namespacesElement = ReaderUtils.getChildElement(catalog, "namespaces", true);
NodeList namespaceElements = namespacesElement.getElementsByTagName("namespace");
Map namespaces = new HashMap();
for (int i = 0; i < namespaceElements.getLength(); i++) {
Element namespaceElement = (Element) namespaceElements.item(i);
try {
Map.Entry tuple = namespaceTuple(namespaceElement);
namespaces.put(tuple.getKey(), tuple.getValue());
//check for default
if ("true".equals(namespaceElement.getAttribute("default"))) {
namespaces.put("", tuple.getValue());
}
} catch (Exception e) {
//TODO: log this
continue;
}
}
return namespaces;
}
/**
* Convenience method for reading connection parameters from a datastore
* element.
*
* @param dataStoreElement The "datastore" element.
*
* @return The map of connection paramters.
*
* @throws Exception If problem parsing any parameters.
*/
protected Map dataStoreParams(Element dataStoreElement)
throws Exception {
Element paramsElement = ReaderUtils.getChildElement(dataStoreElement,
"connectionParameters", true);
NodeList paramList = paramsElement.getElementsByTagName("parameter");
Map params = new HashMap();
for (int i = 0; i < paramList.getLength(); i++) {
Element paramElement = (Element) paramList.item(i);
String key = ReaderUtils.getAttribute(paramElement, "name", true);
String value = ReaderUtils.getAttribute(paramElement, "value", true);
params.put(key, value);
}
return params;
}
/**
* Convenience method for reading namespace prefix and uri from a namespace
* element.
*
* @param namespaceElement The "namespace" element.
*
* @return A <prefix,uri> tuple.
*
* @throws Exception If problem parsing any parameters.
*/
protected Map.Entry namespaceTuple(Element namespaceElement)
throws Exception {
final String pre = namespaceElement.getAttribute("prefix");
final String uri = namespaceElement.getAttribute("uri");
return new Map.Entry() {
public Object getKey() {
return pre;
}
public Object getValue() {
return uri;
}
public Object setValue(Object value) {
throw new UnsupportedOperationException();
}
};
}
}