[Java] Detect duplicate ids in message members. Fix for issue #597.

Author: mjpt777

sbe-tool/src/main/java/uk/co/real_logic/sbe/xml/Message.java

@@ -15,6 +15,7 @@
  */
 package uk.co.real_logic.sbe.xml;
 
+import org.agrona.collections.IntHashSet;
 import org.agrona.collections.ObjectHashSet;
 import uk.co.real_logic.sbe.ir.Token;
 
@@ -75,7 +76,7 @@ public Message(final Node messageNode, final Map<String, Type> typeByNameMap) th
         semanticType = getAttributeValueOrNull(messageNode, "semanticType");                // optional
         this.typeByNameMap = typeByNameMap;
 
-        fieldList = parseFieldsAndGroups(messageNode);
+        fieldList = parseMembers(messageNode);
         computeAndValidateOffsets(messageNode, fieldList, blockLength);
 
         computedBlockLength = computeMessageRootBlockLength(fieldList);
@@ -162,14 +163,15 @@ public int blockLength()
         return blockLength > computedBlockLength ? blockLength : computedBlockLength;
     }
 
-    private List<Field> parseFieldsAndGroups(final Node node) throws XPathExpressionException
+    private List<Field> parseMembers(final Node node) throws XPathExpressionException
     {
         final XPath xPath = XPathFactory.newInstance().newXPath();
         final NodeList list = (NodeList)xPath.compile(FIELD_OR_GROUP_OR_DATA_EXPR).evaluate(node, NODESET);
         boolean groupEncountered = false, dataEncountered = false;
 
         final ObjectHashSet<String> distinctNames = new ObjectHashSet<>();
-        final List<Field> fieldList = new ArrayList<>();
+        final IntHashSet distinctIds = new IntHashSet();
+        final ArrayList<Field> fieldList = new ArrayList<>();
 
         for (int i = 0, size = list.getLength(); i < size; i++)
         {
@@ -206,6 +208,11 @@ private List<Field> parseFieldsAndGroups(final Node node) throws XPathExpression
                     throw new IllegalStateException("Unknown node name: " + nodeName);
             }
 
+            if (!distinctIds.add(field.id()))
+            {
+                handleError(node, "duplicate id found: " + field.id());
+            }
+
             if (!distinctNames.add(field.name()))
             {
                 handleError(node, "duplicate name found: " + field.name());
@@ -248,7 +255,7 @@ else if (!(dimensionType instanceof CompositeType))
 
         XmlSchemaParser.checkForValidName(node, field.name());
 
-        field.groupFields(parseFieldsAndGroups(node)); // recursive call
+        field.groupFields(parseMembers(node)); // recursive call
 
         return field;
     }

sbe-tool/src/test/java/uk/co/real_logic/sbe/xml/ErrorHandlerTest.java

@@ -138,7 +138,7 @@ public void shouldExitAfterMessage()
         throws Exception
     {
         exceptionRule.expect(IllegalStateException.class);
-        exceptionRule.expectMessage("had 11 errors");
+        exceptionRule.expectMessage("had 13 errors");
 
         final ParserOptions options = ParserOptions.builder().suppressOutput(true).warningsFatal(true).build();
 
@@ -181,12 +181,6 @@ public void shouldExitInvalidFieldNames()
         parse(TestUtil.getLocalResource("error-handler-invalid-name.xml"), options);
     }
 
-    /*
-     * TODO:
-     * left over entry count and length field (warning)
-     * dup field id? (not currently tracked)
-     */
-
     private static void parseTestXmlAddToMap(
         final Map<String, Type> map, final String xPathExpr, final String xml, final ErrorHandler handler)
         throws ParserConfigurationException, XPathExpressionException, IOException, SAXException