Try recovery from exceptions #6

Author: donmendelson

README.md

@@ -22,6 +22,10 @@ java io.fixprotocol.xml.XmlDiff <in-file1> <in-file2> [output-file]
 ```
 If the output file is not provided, then results go to the console.
 
+Optionally, argument `-e <event-filename>` can direct errors to a JSON file suitable for UI rendering.
+
+Optionally, argument `-u` treats XML nodes as unordered so moves among children are not considered significant. Otherwise, a move will result in an add and a remove operation.
+
 ## Merge
 
 The XmlMerge utility takes a base XML file and a difference file and merges the two to produce an new XML file.
@@ -31,9 +35,17 @@ To run the merge utility, run this command line:
 ```
 java io.fixprotocol.xml.XmlMerge <base-xml-file> <diff-file> <output-xml-file>
 ```
+Optionally, argument `-e <event-filename>` can direct errors to a JSON file suitable for UI rendering.
+
+The merge utility attempts to continue even if errors occur. Examples of logged errors:
+
+```
+11:12:53.019 [main] ERROR io.fixprotocol.xml.XmlMerge - Target not found for add; /foo
+11:12:53.035 [main] ERROR io.fixprotocol.xml.XmlMerge - Invalid XPath expression for remove; /aaa/fff[
+```
 
 ## License
-© Copyright 2017-2019 FIX Protocol Limited
+© Copyright 2017-2021 FIX Protocol Limited
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.

pom.xml

@@ -5,7 +5,7 @@
 	<groupId>io.fixprotocol.xml</groupId>
 	<artifactId>diff-merge</artifactId>
 	<description>Diff/merge tool for XML files</description>
-	<version>1.4.1-SNAPSHOT</version>
+	<version>1.5.1-SNAPSHOT</version>
 	<name>${project.groupId}:${project.artifactId}</name>
 
 	<prerequisites>
@@ -17,6 +17,7 @@
 		<java.version>11</java.version>
 		<junit.version>5.7.1</junit.version>
 		<log4j.version>2.14.0</log4j.version>
+		<orchestra.version>1.6.10</orchestra.version>
 		<saxon.version>10.3</saxon.version>
 		<ignoreSigningInformation>true</ignoreSigningInformation>
 	</properties>
@@ -64,6 +65,11 @@
 			<artifactId>Saxon-HE</artifactId>
 			<version>${saxon.version}</version>
 		</dependency>
+		<dependency>
+			<groupId>io.fixprotocol.orchestra</groupId>
+			<artifactId>orchestra-common</artifactId>
+			<version>${orchestra.version}</version>
+		</dependency>
 		<dependency>
 			<groupId>org.apache.logging.log4j</groupId>
 			<artifactId>log4j-api</artifactId>

src/main/java/io/fixprotocol/xml/CustomNamespaceContext.java

@@ -32,28 +32,13 @@ public CustomNamespaceContext() {
     namespaces.put("xml", XMLConstants.XML_NS_URI);
     namespaces.put("xsi", XMLConstants.W3C_XML_SCHEMA_INSTANCE_NS_URI);
   }
-  
-  public void populate(Document doc) {
-    final Element baselineRoot = doc.getDocumentElement();
-    final NamedNodeMap rootAttributes = baselineRoot.getAttributes();
-
-    for (int i = 0; i < rootAttributes.getLength(); i++) {
-      final Attr attr = (Attr) rootAttributes.item(i);
-      final String prefix = attr.getPrefix();
-      if ("xmlns".equals(prefix)) {
-        register(attr.getLocalName(), attr.getValue());
-      } else if ("xmlns".equals(attr.getLocalName())) {
-        // default namespace
-        register(XMLConstants.DEFAULT_NS_PREFIX, attr.getValue());
-      }
-    }
-  }
 
+  @Override
   public String getNamespaceURI(String prefix) {
     if (prefix == null) {
       throw new NullPointerException("Null prefix");
     }
-    String uri = namespaces.get(prefix);
+    final String uri = namespaces.get(prefix);
     if (uri != null) {
       return uri;
     } else {
@@ -62,17 +47,35 @@ public String getNamespaceURI(String prefix) {
   }
 
   // This method isn't necessary for XPath processing.
+  @Override
   public String getPrefix(String uri) {
     throw new UnsupportedOperationException();
   }
 
   // This method isn't necessary for XPath processing either.
+  @Override
   public Iterator<String> getPrefixes(String uri) {
     throw new UnsupportedOperationException();
   }
 
+  public void populate(Document doc) {
+    final Element baselineRoot = doc.getDocumentElement();
+    final NamedNodeMap rootAttributes = baselineRoot.getAttributes();
+
+    for (int i = 0; i < rootAttributes.getLength(); i++) {
+      final Attr attr = (Attr) rootAttributes.item(i);
+      final String prefix = attr.getPrefix();
+      if ("xmlns".equals(prefix)) {
+        register(attr.getLocalName(), attr.getValue());
+      } else if ("xmlns".equals(attr.getLocalName())) {
+        // default namespace
+        register(XMLConstants.DEFAULT_NS_PREFIX, attr.getValue());
+      }
+    }
+  }
+
   public void register(String prefix, String uri) {
     namespaces.put(prefix, uri);
   }
 
-}
+}

src/main/java/io/fixprotocol/xml/PatchOpsListener.java

@@ -14,12 +14,12 @@
  */
 package io.fixprotocol.xml;
 
+import static io.fixprotocol.xml.XmlDiffListener.Event.Pos.append;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.nio.charset.StandardCharsets;
 import java.util.concurrent.atomic.AtomicBoolean;
-
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
 import javax.xml.parsers.ParserConfigurationException;
@@ -29,18 +29,15 @@
 import javax.xml.transform.TransformerFactory;
 import javax.xml.transform.dom.DOMSource;
 import javax.xml.transform.stream.StreamResult;
-
 import org.w3c.dom.Attr;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.w3c.dom.Node;
 import org.w3c.dom.Text;
 
-import static io.fixprotocol.xml.XmlDiffListener.Event.Pos.*;
-
 /**
  * Writes XML diffs as patch operations specified by IETF RFC 5261
- * 
+ *
  * @author Don Mendelson
  * @see <a href="https://tools.ietf.org/html/rfc5261">An Extensible Markup Language (XML) Patch
  *      Operations Framework Utilizing XML Path Language (XPath) Selectors</a>
@@ -54,41 +51,42 @@ public class PatchOpsListener implements XmlDiffListener {
 
   /**
    * Constructs a listener with an output stream
+   *
    * @throws IOException if an IO error occurs
    * @throws ParserConfigurationException if a configuration error occurs
    * @throws TransformerConfigurationException if a configuration error occurs
-   * 
+   *
    */
   public PatchOpsListener(OutputStream out)
       throws IOException, ParserConfigurationException, TransformerConfigurationException {
     writer = new OutputStreamWriter(out, StandardCharsets.UTF_8);
 
-    DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
+    final DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
     dbFactory.setNamespaceAware(true);
-    DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
+    final DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
     document = dBuilder.newDocument();
     rootElement = document.createElement("diff");
     document.appendChild(rootElement);
   }
 
   /*
    * (non-Javadoc)
-   * 
+   *
    * @see java.util.function.Consumer#accept(java.lang.Object)
    */
   @Override
   public void accept(Event t) {
 
     switch (t.getDifference()) {
       case ADD:
-        Element addElement = document.createElement("add");
+        final Element addElement = document.createElement("add");
         rootElement.appendChild(addElement);
 
         if (t.getValue() instanceof Attr) {
           // add attribute
           addElement.setAttribute("sel", t.getXpath());
           addElement.setAttribute("type", "@" + t.getValue().getNodeName());
-          Text textNode = document.createTextNode(t.getValue().getNodeValue());
+          final Text textNode = document.createTextNode(t.getValue().getNodeValue());
           addElement.appendChild(textNode);
         } else if (t.getValue() instanceof Element) {
           // add element
@@ -97,30 +95,30 @@ public void accept(Event t) {
             addElement.setAttribute("pos", t.getPos().toString());
           }
           // will import child text node if it exists (deep copy)
-          Element newValue = (Element) document.importNode(t.getValue(), true);
+          final Element newValue = (Element) document.importNode(t.getValue(), true);
           addElement.appendChild(newValue);
         }
 
         break;
       case REPLACE:
-        Element replaceElement = document.createElement("replace");
+        final Element replaceElement = document.createElement("replace");
         rootElement.appendChild(replaceElement);
 
         if (t.getValue() instanceof Attr) {
           // replace attribute
           replaceElement.setAttribute("sel", t.getXpath());
-          Text textNode = document.createTextNode(t.getValue().getNodeValue());
+          final Text textNode = document.createTextNode(t.getValue().getNodeValue());
           replaceElement.appendChild(textNode);
         } else {
           // replace element
           replaceElement.setAttribute("sel", t.getXpath());
           // will import child text node if it exists
-          Node newValue = document.importNode(t.getValue(), true);
+          final Node newValue = document.importNode(t.getValue(), true);
           replaceElement.appendChild(newValue);
         }
         break;
       case REMOVE:
-        Element removeElement = document.createElement("remove");
+        final Element removeElement = document.createElement("remove");
         rootElement.appendChild(removeElement);
         removeElement.setAttribute("sel", t.getXpath());
         break;
@@ -131,18 +129,18 @@ public void accept(Event t) {
 
   /*
    * (non-Javadoc)
-   * 
+   *
    * @see java.lang.AutoCloseable#close()
    */
   @Override
   public void close() throws Exception {
     // Idempotent - only close once
     if (isClosed.compareAndSet(false, true)) {
-      TransformerFactory transformerFactory = TransformerFactory.newInstance();
-      Transformer transformer = transformerFactory.newTransformer();
+      final TransformerFactory transformerFactory = TransformerFactory.newInstance();
+      final Transformer transformer = transformerFactory.newTransformer();
       transformer.setOutputProperty(OutputKeys.INDENT, "yes");
-      DOMSource source = new DOMSource(document);
-      StreamResult result = new StreamResult(writer);
+      final DOMSource source = new DOMSource(document);
+      final StreamResult result = new StreamResult(writer);
       transformer.transform(source, result);
       writer.close();
     }