Rearrangement of project structure

src/main/java/processors/XalanNamespaceResolver.java

@@ -0,0 +1,121 @@
+package processors;
+
+import org.w3c.dom.*;
+
+import javax.xml.XMLConstants;
+import javax.xml.namespace.NamespaceContext;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+
+public class XalanNamespaceResolver implements NamespaceContext {
+    private static final String DEFAULT_NS = "DEFAULT";
+    private Map<String, String> prefix2Uri = new HashMap<String, String>();
+    private Map<String, String> uri2Prefix = new HashMap<String, String>();
+
+    /**
+     * This constructor parses the document and stores all namespaces it can
+     * find. If toplevelOnly is true, only namespaces in the root are used.
+     *
+     * @param document
+     *            source document
+     * @param toplevelOnly
+     *            restriction of the search to enhance performance
+     */
+    public XalanNamespaceResolver(Document document, boolean toplevelOnly) {
+        examineNode(document.getFirstChild(), toplevelOnly);
+        System.out.println("The list of the cached namespaces:");
+        for (String key : prefix2Uri.keySet()) {
+            System.out.println("prefix " + key + ": uri " + prefix2Uri.get(key));
+        }
+    }
+
+    /**
+     * A single node is read, the namespace attributes are extracted and stored.
+     *
+     * @param node
+     *            to examine
+     * @param attributesOnly,
+     *            if true no recursion happens
+     */
+    private void examineNode(Node node, boolean attributesOnly) {
+        NamedNodeMap attributes = node.getAttributes();
+        for (int i = 0; i < attributes.getLength(); i++) {
+            Node attribute = attributes.item(i);
+            storeAttribute((Attr) attribute);
+        }
+
+        if (!attributesOnly) {
+            NodeList chields = node.getChildNodes();
+            for (int i = 0; i < chields.getLength(); i++) {
+                Node chield = chields.item(i);
+                if (chield.getNodeType() == Node.ELEMENT_NODE){
+                    examineNode(chield, false);
+                }
+
+            }
+        }
+    }
+
+    /**
+     * This method looks at an attribute and stores it, if it is a namespace
+     * attribute.
+     *
+     * @param attribute
+     *            to examine
+     */
+    private void storeAttribute(Attr attribute) {
+        // examine the attributes in namespace xmlns
+        String uri = attribute.getNamespaceURI();
+        String name = attribute.getLocalName();
+        String name2 = attribute.getName();
+        String value = attribute.getNodeValue();
+        if (attribute.getNodeValue() != null
+                /*&& attribute.getNamespaceURI().equals(
+                XMLConstants.XMLNS_ATTRIBUTE_NS_URI)*/) {
+            // Default namespace xmlns="uri goes here"
+            if (attribute.getNodeName().equals(XMLConstants.XMLNS_ATTRIBUTE)) {
+                putInCache(DEFAULT_NS, attribute.getNodeValue());
+            } else {
+                // The defined prefixes are stored here
+                putInCache(attribute.getName().replace("xmlns:", ""), attribute.getNodeValue());
+            }
+        }
+
+    }
+
+    private void putInCache(String prefix, String uri) {
+        prefix2Uri.put(prefix, uri);
+        uri2Prefix.put(uri, prefix);
+    }
+
+    /**
+     * This method is called by XPath. It returns the default namespace, if the
+     * prefix is null or "".
+     *
+     * @param prefix
+     *            to search for
+     * @return uri
+     */
+    public String getNamespaceURI(String prefix) {
+        if (prefix == null || prefix.equals(XMLConstants.DEFAULT_NS_PREFIX)) {
+            return prefix2Uri.get(DEFAULT_NS);
+        } else {
+            return prefix2Uri.get(prefix);
+        }
+    }
+
+    /**
+     * This method is not needed in this context, but can be implemented in a
+     * similar way.
+     */
+    public String getPrefix(String namespaceURI) {
+        return uri2Prefix.get(namespaceURI);
+    }
+
+    public Iterator getPrefixes(String namespaceURI) {
+        // Not implemented
+        return null;
+    }
+
+}