--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/artifacts-common/src/main/java/org/dive4elements/artifacts/common/utils/XMLUtils.java	Thu Apr 25 10:53:15 2013 +0200
@@ -0,0 +1,617 @@
+/*
+ * Copyright (c) 2010 by Intevation GmbH
+ *
+ * This program is free software under the LGPL (>=v2.1)
+ * Read the file LGPL.txt coming with the software for details
+ * or visit http://www.gnu.org/licenses/ if it does not exist.
+ */
+
+package de.intevation.artifacts.common.utils;
+
+import java.util.List;
+import java.util.ArrayList;
+import java.util.Map;
+import java.util.LinkedHashMap;
+import java.util.zip.GZIPInputStream;
+import java.util.zip.GZIPOutputStream;
+
+import java.io.ByteArrayInputStream;
+import java.io.FileInputStream;
+import java.io.BufferedInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.StringWriter;
+
+import javax.xml.namespace.NamespaceContext;
+import javax.xml.namespace.QName;
+
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+
+import javax.xml.transform.Transformer;
+import javax.xml.transform.TransformerConfigurationException;
+import javax.xml.transform.TransformerException;
+import javax.xml.transform.TransformerFactory;
+import javax.xml.transform.TransformerFactoryConfigurationError;
+
+import javax.xml.transform.dom.DOMSource;
+
+import javax.xml.transform.stream.StreamResult;
+
+import javax.xml.xpath.XPath;
+import javax.xml.xpath.XPathConstants;
+import javax.xml.xpath.XPathExpressionException;
+import javax.xml.xpath.XPathFactory;
+import javax.xml.xpath.XPathVariableResolver;
+
+import org.apache.log4j.Logger;
+
+import org.w3c.dom.Attr;
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+import org.w3c.dom.Node;
+
+import org.xml.sax.SAXException;
+
+/**
+ * Some helper functions to ease work with XML concering namespaces, XPATH
+ * and so on.
+ *  @author <a href="mailto:sascha.teichmann@intevation.de">Sascha L. Teichmann</a>
+ */
+public final class XMLUtils
+{
+    /** W3C URL of XForms. */
+    public static final String XFORM_URL    = "http://www.w3.org/2002/xforms";
+
+    /** W3C prefix of XForms. */
+    public static final String XFORM_PREFIX = "xform";
+
+    /** Logger for this class. */
+    private static Logger logger = Logger.getLogger(XMLUtils.class);
+
+    private XMLUtils() {
+    }
+
+    /**
+     * Helper class to generate elements and attributes with
+     * namespaces.
+     */
+    public static class ElementCreator
+    {
+        /** Owner document of the elements to be created. */
+        protected Document document;
+
+        /** Namespace to be used. */
+        protected String   ns;
+
+        /** Prefix to be used. */
+        protected String   prefix;
+
+        /**
+         * Constructor to create an element/attribute creator
+         * with a given namespace and namespace prefix using a
+         * given owner document.
+         * @param document The owning document
+         * @param ns       The namespace
+         * @param prefix   The namespace prefix
+         */
+        public ElementCreator(Document document, String ns, String prefix) {
+            this.document = document;
+            this.ns       = ns;
+            this.prefix   = prefix;
+        }
+
+        /**
+         * Creates a new element using the owning document with
+         * the this creators namespace and namespace prefix.
+         * @param name The name of the element
+         * @return     The new element
+         */
+        public Element create(String name) {
+            Element element = document.createElementNS(ns, name);
+            element.setPrefix(prefix);
+            return element;
+        }
+
+        /**
+         * Adds a new attribute and its value to a given element.
+         * It does not set the namespace prefix.
+         * @param element The element to add the attribute to
+         * @param name    The name of the attribute
+         * @param value   The value of the attribute
+         */
+        public void addAttr(Element element, String name, String value) {
+            addAttr(element, name, value, false);
+        }
+
+        /**
+         * Adds a new attribute and its value to a given element.
+         * If the namespace prefix is used is decided by the 'addPrefix' flag.
+         * @param element The element to add the attribute to
+         * @param name    The name of the attribute
+         * @param value   The value of the attribute
+         * @param addPrefix If true the creators namespace prefix is
+         * set on the attribute.
+         */
+        public void addAttr(
+            Element element,
+            String  name,
+            String  value,
+            boolean addPrefix
+        ) {
+            if (addPrefix) {
+                Attr attr = document.createAttributeNS(ns, name);
+                attr.setValue(value);
+                attr.setPrefix(prefix);
+
+                element.setAttributeNode(attr);
+            }
+            else {
+                element.setAttribute(name, value);
+            }
+        }
+    } // class ElementCreator
+
+    /**
+     * Creates a new XML document
+     * @return the new XML document ot null if something went wrong during
+     * creation.
+     */
+    public static final Document newDocument() {
+        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
+        factory.setNamespaceAware(true);
+
+        try {
+            return factory.newDocumentBuilder().newDocument();
+        }
+        catch (ParserConfigurationException pce) {
+            logger.error(pce.getLocalizedMessage(), pce);
+        }
+        return null;
+    }
+
+
+    /**
+     * Create xml/string representation of element (nested in otherwise empty
+     * document).
+     * @param element element to inspect in string.
+     * @return string with xml representation of element.
+     */
+    public final static String toString(Node node) {
+        Document doc = newDocument();
+        doc.appendChild(doc.importNode(node,true));
+        return toString(doc);
+    }
+
+
+    /**
+     * Loads a XML document namespace aware from a file
+     * @param file The file to load.
+     * @return the XML document or null if something went wrong
+     * during loading.
+     */
+    public static final Document parseDocument(File file) {
+        InputStream inputStream = null;
+        try {
+            inputStream = new BufferedInputStream(new FileInputStream(file));
+            return parseDocument(inputStream);
+        }
+        catch (IOException ioe) {
+            logger.error(ioe.getLocalizedMessage(), ioe);
+        }
+        finally {
+            if (inputStream != null) {
+                try { inputStream.close(); }
+                catch (IOException ioe) {}
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Parses a String to a xml document.
+     *
+     * @param string The xml string
+     * @return the XML document or null if something went wrong.
+     */
+    public static final Document parseDocument(String string) {
+        InputStream inputStream = new ByteArrayInputStream(string.getBytes());
+        return parseDocument(inputStream);
+    }
+
+
+    public static final Document parseDocument(InputStream inputStream) {
+        return parseDocument(inputStream, Boolean.TRUE);
+    }
+
+    public static final Document parseDocument(
+        InputStream inputStream,
+        Boolean     namespaceAware
+    ) {
+        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
+
+        if (namespaceAware != null) {
+            factory.setNamespaceAware(namespaceAware.booleanValue());
+        }
+
+        try {
+            return factory.newDocumentBuilder().parse(inputStream);
+        }
+        catch (ParserConfigurationException pce) {
+            logger.error(pce.getLocalizedMessage(), pce);
+        }
+        catch (SAXException se) {
+            logger.error(se.getLocalizedMessage(), se);
+        }
+        catch (IOException ioe) {
+            logger.error(ioe.getLocalizedMessage(), ioe);
+        }
+        return null;
+    }
+
+    /**
+     * Creates a new XPath without a namespace context.
+     * @return the new XPath.
+     */
+    public static final XPath newXPath() {
+        return newXPath(null, null);
+    }
+
+    /**
+     * Creates a new XPath with a given namespace context.
+     * @param namespaceContext The namespace context to be used or null
+     * if none should be used.
+     * @return The new XPath
+     */
+    public static final XPath newXPath(
+        NamespaceContext      namespaceContext,
+        XPathVariableResolver resolver)
+    {
+        XPathFactory factory = XPathFactory.newInstance();
+        XPath        xpath   = factory.newXPath();
+        if (namespaceContext != null) {
+            xpath.setNamespaceContext(namespaceContext);
+        }
+
+        if (resolver != null) {
+            xpath.setXPathVariableResolver(resolver);
+        }
+        return xpath;
+    }
+
+    /**
+     * Evaluates an XPath query on a given object and returns the result
+     * as a given type. No namespace context is used.
+     * @param root  The object which is used as the root of the tree to
+     * be searched in.
+     * @param query The XPath query
+     * @param returnTyp The type of the result.
+     * @return The result of type 'returnTyp' or null if something
+     * went wrong during XPath evaluation.
+     */
+    public static final Object xpath(
+        Object root,
+        String query,
+        QName  returnTyp
+    ) {
+        return xpath(root, query, returnTyp, null);
+    }
+
+    /**
+     * Evaluates an XPath query on a given object and returns the result
+     * as a string. A given namespace context is used.
+     * @param root  The object which is used as the root of the tree to
+     * be searched in.
+     * @param query The XPath query
+     * @param namespaceContext The namespace context to be used or null
+     * if none should be used.
+     * @return The result of the query or null if something went wrong
+     * during XPath evaluation.
+     */
+    public static final String xpathString(
+        Object root, String query, NamespaceContext namespaceContext
+    ) {
+        return (String)xpath(
+            root, query, XPathConstants.STRING, namespaceContext);
+    }
+
+    /**
+     * Evaluates an XPath query on a given object and returns the result
+     * as a given type. Optionally a namespace context is used.
+     * @param root The object which is used as the root of the tree to
+     * be searched in.
+     * @param query The XPath query
+     * @param returnType The type of the result.
+     * @param namespaceContext The namespace context to be used or null
+     * if none should be used.
+     * @return The result of type 'returnTyp' or null if something
+     * went wrong during XPath evaluation.
+     */
+    public static final Object xpath(
+        Object           root,
+        String           query,
+        QName            returnType,
+        NamespaceContext namespaceContext
+    ) {
+        return xpath(root, query, returnType, namespaceContext, null);
+    }
+
+    public static final Object xpath(
+        Object           root,
+        String           query,
+        QName            returnType,
+        NamespaceContext namespaceContext,
+        Map<String, String> variables)
+    {
+        if (root == null) {
+            return null;
+        }
+
+        XPathVariableResolver resolver = variables != null
+            ? new MapXPathVariableResolver(variables)
+            : null;
+
+        try {
+            XPath xpath = newXPath(namespaceContext, resolver);
+            if (xpath != null) {
+                return xpath.evaluate(query, root, returnType);
+            }
+        }
+        catch (XPathExpressionException xpee) {
+            logger.error(xpee.getLocalizedMessage(), xpee);
+        }
+
+        return null;
+    }
+
+    /**
+     * Streams out an XML document to a given output stream.
+     * @param document The document to be streamed out.
+     * @param out      The output stream to be used.
+     * @return true if operation succeeded else false.
+     */
+    public static boolean toStream(Document document, OutputStream out) {
+        try {
+            Transformer transformer =
+                TransformerFactory.newInstance().newTransformer();
+            DOMSource    source = new DOMSource(document);
+            StreamResult result = new StreamResult(out);
+            transformer.transform(source, result);
+            return true;
+        }
+        catch (TransformerConfigurationException tce) {
+            logger.error(tce.getLocalizedMessage(), tce);
+        }
+        catch (TransformerFactoryConfigurationError tfce) {
+            logger.error(tfce.getLocalizedMessage(), tfce);
+        }
+        catch (TransformerException te) {
+            logger.error(te.getLocalizedMessage(), te);
+        }
+
+        return false;
+    }
+
+    public static String toString(Document document) {
+        try {
+            Transformer transformer =
+                TransformerFactory.newInstance().newTransformer();
+            DOMSource    source = new DOMSource(document);
+            StringWriter out    = new StringWriter();
+            StreamResult result = new StreamResult(out);
+            transformer.transform(source, result);
+            out.flush();
+            return out.toString();
+        }
+        catch (TransformerConfigurationException tce) {
+            logger.error(tce.getLocalizedMessage(), tce);
+        }
+        catch (TransformerFactoryConfigurationError tfce) {
+            logger.error(tfce.getLocalizedMessage(), tfce);
+        }
+        catch (TransformerException te) {
+            logger.error(te.getLocalizedMessage(), te);
+        }
+
+        return null;
+    }
+
+    public static byte [] toByteArray(Document document) {
+        return toByteArray(document, false);
+    }
+
+    /**
+     * Transforms an XML document into a byte array.
+     * @param document The document to be streamed out.
+     * @param compress The document should be compressed, too.
+     * @return the byte array or null if operation failed or
+     * document is null.
+     */
+    public static byte [] toByteArray(Document document, boolean compress) {
+        if (document != null) {
+            try {
+                ByteArrayOutputStream baos = new ByteArrayOutputStream();
+                OutputStream out = compress
+                    ? new GZIPOutputStream(baos)
+                    : baos;
+                boolean success = toStream(document, out);
+                out.flush();
+                out.close();
+                return success
+                    ? baos.toByteArray()
+                    : null;
+            }
+            catch (IOException ioe) {
+                logger.error(ioe);
+            }
+        }
+        return null;
+    }
+
+    public static Document fromByteArray(byte [] data) {
+        return fromByteArray(data, false);
+    }
+
+    public static Document fromByteArray(byte [] data, boolean decompress) {
+        if (data != null) {
+            InputStream in = new ByteArrayInputStream(data);
+            try {
+                if (decompress) {
+                    in = new GZIPInputStream(in);
+                }
+                return parseDocument(in);
+            }
+            catch (IOException ioe) {
+                logger.error(ioe);
+            }
+            finally {
+                try {
+                    in.close();
+                }
+                catch (IOException ioe) {
+                    logger.error(ioe);
+                }
+            }
+        }
+        return null;
+    }
+
+    private static class BuildResult {
+        List<Node>          children;
+        Map<String, String> attributes;
+        BuildResult() {
+            children   = new ArrayList<Node>();
+            attributes = new LinkedHashMap<String, String>();
+        }
+
+        void setAttributes(Element element) {
+            for (Map.Entry<String, String> entry: attributes.entrySet()) {
+                element.setAttribute(entry.getKey(), entry.getValue());
+            }
+        }
+
+        void finish(Element element) {
+            setAttributes(element);
+            for (Node child: children) {
+                element.appendChild(child);
+            }
+        }
+
+        void add(Node node) {
+            children.add(node);
+        }
+
+        void add(String key, Object value) {
+            attributes.put(key, value != null ? value.toString() : "null");
+        }
+
+        int numChildren() {
+            return children.size();
+        }
+
+        Node firstChild() {
+            return children.get(0);
+        }
+    } // class BuildResult
+
+    private static BuildResult recursiveBuild(
+        List     list,
+        Document document
+    ) {
+        BuildResult result = new BuildResult();
+        for (Object entry: list) {
+            if (entry instanceof Map) {
+                BuildResult subResult = recursiveBuild(
+                    (Map<String, Object>)entry, document);
+                if (subResult.numChildren() == 1) {
+                    result.add(subResult.firstChild());
+                }
+                else {
+                    Element element = document.createElement("map");
+                    subResult.finish(element);
+                    result.add(element);
+                }
+            }
+            else if (entry instanceof List) {
+                Element element = document.createElement("list");
+                BuildResult subResult = recursiveBuild((List)entry, document);
+                subResult.finish(element);
+                result.add(element);
+            }
+            else {
+                Element element = document.createElement("entry");
+                element.setAttribute(
+                    "value",
+                    entry != null ? entry.toString() : "null");
+            }
+        }
+        return result;
+    }
+
+    private static BuildResult recursiveBuild(
+        Map<String, Object> map,
+        Document            document
+    ) {
+        BuildResult result = new BuildResult();
+
+        List<Node> nodes = new ArrayList<Node>();
+        for (Map.Entry<String, Object> entry: map.entrySet()) {
+            Object value = entry.getValue();
+            if (value instanceof Map) {
+                Element element = document.createElement(entry.getKey());
+                BuildResult subResult = recursiveBuild(
+                    (Map<String, Object>)value, document);
+                subResult.finish(element);
+                result.add(element);
+            }
+            else if (value instanceof List) {
+                Element element = document.createElement(entry.getKey());
+                BuildResult subResult = recursiveBuild((List)value, document);
+                subResult.finish(element);
+                result.add(element);
+            }
+            else {
+                result.add(entry.getKey(), value);
+            }
+        }
+        return result;
+    }
+
+    public static Document jsonToXML(String input) {
+        Document document = newDocument();
+
+        if (document == null) {
+            return null;
+        }
+
+        Map<String, Object> map;
+        try {
+            map = JSON.parse(input);
+        }
+        catch (IOException ioe) {
+            logger.error(ioe);
+            return null;
+        }
+
+        BuildResult roots = recursiveBuild(map, document);
+
+        int N = roots.children.size();
+
+        if (N == 1) {
+            document.appendChild(roots.children.get(0));
+        }
+        else if (N > 1) {
+            Node root = document.createElement("root");
+            for (int i = 0; i < N; ++i) {
+                root.appendChild(roots.children.get(i));
+            }
+            document.appendChild(root);
+        }
+
+        return document;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :