[Yanel-commits] rev 28304 - public/yanel/trunk/src/core/java/org/wyona/yanel/core/util

[michi at wyona.com]

Author: michi
Date: 2007-11-01 09:40:08 +0100 (Thu, 01 Nov 2007)
New Revision: 28304

Added:
   public/yanel/trunk/src/core/java/org/wyona/yanel/core/util/ConfigurationUtil.java
Log:
configuration util added for trannsforming an avalon configuration into a DOM Document

Added: public/yanel/trunk/src/core/java/org/wyona/yanel/core/util/ConfigurationUtil.java
===================================================================
--- public/yanel/trunk/src/core/java/org/wyona/yanel/core/util/ConfigurationUtil.java	                        (rev 0)
+++ public/yanel/trunk/src/core/java/org/wyona/yanel/core/util/ConfigurationUtil.java	2007-11-01 08:40:08 UTC (rev 28304)
@@ -0,0 +1,126 @@
+/*
+ * Copyright 2007 Wyona
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.wyona.org/licenses/APACHE-LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.wyona.yanel.core.util;
+
+import javax.xml.parsers.DocumentBuilderFactory;
+
+import org.apache.avalon.framework.configuration.Configuration;
+import org.apache.log4j.Category;
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+
+/**
+ * Configuration utility allowing for custom configuration fragments
+ * 
+ * @author ok at ncode.ch
+ * 
+ */
+public class ConfigurationUtil {
+
+    /**
+     * The log category instance
+     */
+    private static final Category log = Category.getInstance(ConfigurationUtil.class);
+
+    /**
+     * Create a DOM Document from a custom config element modelled with avalon
+     * 
+     * @param confElement
+     *            The configuration element
+     * @param rootName
+     *            The root element name
+     * @param rootNamespace
+     *            The target namespace
+     * @return
+     */
+    public static Document getCustomConfiguration(Configuration repoConfigElement, String rootName,
+            String rootNamespace) {
+        if (repoConfigElement == null || repoConfigElement.getChildren() == null
+            || repoConfigElement.getChildren().length == 0) {
+            log.debug("Did not find any child elements in " + repoConfigElement);
+            return null;
+        }
+
+        log.debug("Creating custom config - rootName=" + rootName + ", rootNamespace="
+            + rootNamespace);
+
+        Document doc = null;
+        DocumentBuilderFactory dbf = javax.xml.parsers.DocumentBuilderFactory.newInstance();
+        dbf.setNamespaceAware(true);
+        try {
+            javax.xml.parsers.DocumentBuilder parser = dbf.newDocumentBuilder();
+            org.w3c.dom.DOMImplementation impl = parser.getDOMImplementation();
+            org.w3c.dom.DocumentType doctype = null;
+            doc = impl.createDocument(rootNamespace, rootName, doctype);
+
+            Configuration[] children = repoConfigElement.getChildren();
+            if (children.length > 0) {
+                Element rootElement = doc.getDocumentElement();
+                log.debug("root element " + rootElement);
+                for (int i = 0; i < children.length; i++) {
+                    rootElement.appendChild(ConfigurationUtil.createElement(children[i], doc));
+                }
+            }
+            return doc;
+        } catch (Exception e) {
+            log.error(e.getMessage(), e);
+            return null;
+        }
+
+        // original comment by michi:
+        // avalon ConfigurationUtil doesn't seem to work properly
+        /*
+         * org.w3c.dom.Element element = ConfigurationUtil.toElement(customConfig);
+         * log.error("DEBUG: element: " + element.getLocalName()); org.w3c.dom.Document doc =
+         * element.getOwnerDocument(); org.w3c.dom.Element rootElement = doc.getDocumentElement();
+         * rootElement.appendChild(element); return doc;
+         */
+    }
+
+    /**
+     * Parse a configuration node into a element and add it to the document. <br/>This method may
+     * call itself recusively.
+     * 
+     * @param conf
+     *            The configuration element to parse
+     * @param doc
+     *            The DOM document to create elements for
+     * 
+     * @return Returns the created element
+     */
+    private static Element createElement(Configuration config, Document doc) throws Exception {
+
+        Element element = doc.createElementNS(config.getNamespace(), config.getName());
+        String[] attrs = config.getAttributeNames();
+        for (int i = 0; i < attrs.length; i++) {
+            element.setAttributeNS(config.getNamespace(), attrs[i], config.getAttribute(attrs[i]));
+        }
+        // TODO: Does not work for elements with mixed content (text and
+        // elements)
+        try {
+            element.appendChild(doc.createTextNode(config.getValue()));
+        } catch (Exception e) {
+            log.debug("No value: " + element.getLocalName() + "  - skipped child creation");
+        }
+        Configuration[] children = config.getChildren();
+        if (children.length > 0) {
+            for (int i = 0; i < children.length; i++) {
+                element.appendChild(ConfigurationUtil.createElement(children[i], doc));
+            }
+        }
+        return element;
+    }
+}