Replaced xpath handling implementation

Backend/xslt-rest/src/main/java/com/r11/tools/xslt/processors/Xalan.java

@@ -1,8 +1,12 @@
 package com.r11.tools.xslt.processors;
 
+import net.sf.saxon.lib.RawResult;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.apache.xpath.XPathAPI;
 import org.w3c.dom.Document;
+import org.w3c.dom.Node;
+import org.w3c.dom.traversal.NodeIterator;
 import org.xml.sax.InputSource;
 
 import javax.xml.XMLConstants;
@@ -19,8 +23,7 @@ import javax.xml.xpath.XPath;
 import javax.xml.xpath.XPathConstants;
 import javax.xml.xpath.XPathExpression;
 import javax.xml.xpath.XPathFactory;
-import java.io.StringReader;
-import java.io.StringWriter;
+import java.io.*;
 
 /**
  * Handler for Xalan engine
@@ -53,6 +56,13 @@ public class Xalan {
         return sw.toString();
     }
 
+    private static boolean isTextNode(Node n) {
+        if (n == null)
+            return false;
+        short nodeType = n.getNodeType();
+        return nodeType == Node.CDATA_SECTION_NODE || nodeType == Node.TEXT_NODE;
+    }
+
     /**
      * Process xpath and return either node or wrapped atomic value
      * @deprecated
@@ -62,16 +72,60 @@ public class Xalan {
      * @return xml processed using given xpath
      * @throws Exception thrown on node building errors or invalid xpath
      */
-    public static String processXPath(String data, String transform) throws Exception{
-        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
-        DocumentBuilder builder = factory.newDocumentBuilder();
+    public static String processXPath(String data, String transform) throws Exception {
+//        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
+//        DocumentBuilder builder = factory.newDocumentBuilder();
+//
+//        XPath xpath = XPathFactory.newInstance().newXPath();
+//
+//        xpath.setNamespaceContext(new XalanNamespaceResolver(builder.parse(new InputSource(new StringReader(data))), true));
+//        XPathExpression exp = xpath.compile(transform);
+//        exp.evaluate(new InputSource(new StringReader(data)), XPathConstants.NODESET);
+//        return exp.evaluate(new InputSource(new StringReader(data)));
 
-        XPath xpath = XPathFactory.newInstance().newXPath();
+        //data = "/home/adam/Programowanie/Java/XML Tools/release11-tools-web/SampleData/book.xml";
+        //transform = "/books/book[name = 'Hamlet']";
 
-        xpath.setNamespaceContext(new XalanNamespaceResolver(builder.parse(new InputSource(new StringReader(data))), true));
-        XPathExpression exp = xpath.compile(transform);
-        exp.evaluate(new InputSource(new StringReader(data)), XPathConstants.NODESET);
-        return exp.evaluate(new InputSource(new StringReader(data)));
+
+        // Set up a DOM tree to query.
+        InputSource in = new InputSource(new StringReader(data));
+        DocumentBuilderFactory dfactory = DocumentBuilderFactory.newInstance();
+        dfactory.setNamespaceAware(true);
+        Document doc = dfactory.newDocumentBuilder().parse(in);
+
+        // Set up an identity transformer to use as serializer.
+        Transformer serializer = TransformerFactory.newInstance().newTransformer();
+        serializer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
+
+        // Use the simple XPath API to select a nodeIterator.
+        NodeIterator nl = XPathAPI.selectNodeIterator(doc, transform);
+
+        // Serialize the found nodes to result object.
+        StringBuilder result = new StringBuilder();
+        Node n;
+        while ((n = nl.nextNode())!= null) {
+            StringBuilder sb;
+            if (isTextNode(n)) {
+                // DOM may have more than one node corresponding to a
+                // single XPath text node.  Coalesce all contiguous text nodes
+                // at this level
+                sb = new StringBuilder(n.getNodeValue());
+                for (
+                        Node nn = n.getNextSibling();
+                        isTextNode(nn);
+                        nn = nn.getNextSibling()
+                ) {
+                    result.append(nn.getNodeValue());
+                }
+            } else {
+                ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+                serializer.transform(new DOMSource(n), new StreamResult(new OutputStreamWriter(outputStream)));
+                result.append(outputStream);
+
+            }
+            result.append("\n");
+        }
+        return result.toString();
     }
 
     /**