8280189: JFR: TestPrintXML should print mismatching XML

test/jdk/jdk/jfr/tool/TestPrintXML.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2022, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -47,6 +47,7 @@
 import org.xml.sax.SAXException;
 import org.xml.sax.SAXParseException;
 import org.xml.sax.XMLReader;
+import org.xml.sax.Locator;
 import org.xml.sax.helpers.DefaultHandler;
 
 import jdk.jfr.Timespan;
@@ -105,7 +106,14 @@ public static void main(String... args) throws Throwable {
                 System.out.println();
                 System.out.println("Was (XML)");
                 System.out.println("----------------------");
-                System.out.println(xmlEvent);
+                if (xmlEvent.begin > 0 && xmlEvent.end > 0) {
+                    String lines[] = xml.split("\\r?\\n");
+                    for (int i = xmlEvent.begin - 1; i < xmlEvent.end; i++) {
+                        System.out.println(i + " " + lines[i]);
+                    }
+                } else {
+                    System.out.println("Could not locate XML position");
+                }
                 System.out.println();
                 throw new Exception("Event doesn't match");
             }
@@ -164,6 +172,8 @@ static boolean compare(Object eventObject, Object xmlObject) {
     static class XMLEvent {
         String name;
         private Map<String, Object> values = new HashMap<>();
+        private int begin = -1;
+        private int end = -1;
 
         XMLEvent(String name) {
             this.name = name;
@@ -172,10 +182,15 @@ static class XMLEvent {
 
     public static final class RecordingHandler extends DefaultHandler {
 
+        private Locator locator;
         private Stack<Object> objects = new Stack<>();
         private Stack<SimpleEntry<String, String>> elements = new Stack<>();
         private List<XMLEvent> events = new ArrayList<>();
 
+        public void setDocumentLocator(Locator locator) {
+            this.locator = locator;
+        }
+
         @Override
         public void startElement(String uri, String localName, String qName, Attributes attrs) throws SAXException {
             elements.push(new SimpleEntry<>(attrs.getValue("name"), attrs.getValue("index")));
@@ -187,7 +202,9 @@ public void startElement(String uri, String localName, String qName, Attributes
 
             switch (qName) {
             case "event":
-                objects.push(new XMLEvent(attrs.getValue("type")));
+                XMLEvent event = new XMLEvent(attrs.getValue("type"));
+                event.begin = locator.getLineNumber();
+                objects.push(event);
                 break;
             case "struct":
                 objects.push(new HashMap<String, Object>());
@@ -223,7 +240,9 @@ public void endElement(String uri, String localName, String qName) {
                 String name = element.getKey();
                 Object value = objects.pop();
                 if (objects.isEmpty()) {
-                    events.add((XMLEvent) value);
+                    XMLEvent event = (XMLEvent) value;
+                    event.end = locator.getLineNumber();
+                    events.add(event);
                     return;
                 }
                 if (value instanceof StringBuilder) {