How to get the ancestor node from this XML document?

I have an xml document, say of the format :

<DynamicReport>
<DynamicReportDefId>501</DynamicReportDefId>
<DynamicReportDefName>Test report</DynamicReportDefName>
<DynamicReportDefSource>Live</DynamicReportDefSource>
<IsPrivate>false</IsPrivate>
<showSummaryRowsOnly>false</showSummaryRowsOnly>
<Limit>false</Limit>
<LimitRows/>
<InvUserId/>
<Version>0</Version>
<Category/>
<Columns class="array">
<Column>
<TableName>vwdynfirms</TableName>
<ColumnName>firmlongname</ColumnName>
<FormattingInfo>
<Header>
<DisplayName>Firm Long Name</DisplayName>
<FontInfo>
<Font/>
<FontSize/>
<IsBold/>
<IsItalic/>
<IsUnderline/>
<TextColor/>
<BackgroundColor/>
</FontInfo>
<AlignmentInfo>
<HorizontalAlignment/>
<VerticalAlignment/>
</AlignmentInfo>
<BorderInfo>
<BorderLeft/>
<BorderRight/>
<BorderTop/>
<BorderBottom/>
</BorderInfo>
</Header>
<Detail>
<FontInfo>
<Font/>
<FontSize/>
<IsBold/>
<IsItalic/>
<IsUnderline/>
<TextColor/>
<BackgroundColor/>
</FontInfo>
<AlignmentInfo>
<HorizontalAlignment/>
<VerticalAlignment/>
</AlignmentInfo>
<BorderInfo>
<BorderLeft/>
<BorderRight/>
<BorderTop/>
<BorderBottom/>
</BorderInfo>
<DisplayPattern/>
</Detail>
</FormattingInfo>
</Column>
<Column>
<TableName>vwdynfirms</TableName>
<ColumnName>firmname</ColumnName>
<FormattingInfo>
<Header>
<DisplayName>Firm Name</DisplayName>
<FontInfo>
<Font>Calibri</Font>
<FontSize>14</FontSize>
<IsBold>true</IsBold>
<IsItalic/>
<IsUnderline/>
<TextColor>#FF0080</TextColor>
<BackgroundColor>#FFFFFF</BackgroundColor>
</FontInfo>
<AlignmentInfo>
<HorizontalAlignment>left</HorizontalAlignment>
<VerticalAlignment>bottom</VerticalAlignment>
</AlignmentInfo>
<BorderInfo>
<BorderLeft/>
<BorderRight/>
<BorderTop/>
<BorderBottom>true</BorderBottom>
</BorderInfo>
</Header>
<Detail>
<FontInfo>
<Font/>
<FontSize/>
<IsBold/>
<IsItalic/>
<IsUnderline/>
<TextColor/>
<BackgroundColor/>
</FontInfo>
<AlignmentInfo>
<HorizontalAlignment/>
<VerticalAlignment/>
</AlignmentInfo>
<BorderInfo>
<BorderLeft/>
<BorderRight/>
<BorderTop/>
<BorderBottom/>
</BorderInfo>
<DisplayPattern/>
</Detail>
</FormattingInfo>
</Column>
</Columns>
</DynamicReport>

From this xml document, I want to get the TextColor and the BackgroundColor for a particular Column and then store them in a map. I am expecting the map to be of the format Map<String>, List<String>
where the key is the ColumnName and the list of strings would be the two colors (TextColor and the BackgroundColor) as the values for the column in the map for now.

I have written the code, wherein I am not returning anything until I am able to get the column name by traversing back :

    //Getting the column from the colors for all the columns
public static void getColors(Document doc)
{
String expressionGroupedCol = "/DynamicReport/Columns/Column/FormattingInfo/Header/FontInfo";
XPath xPath = XPathFactory.newInstance().newXPath();
try {
NodeList nodeList = (NodeList) xPath.compile(expressionGroupedCol).evaluate(
doc, XPathConstants.NODESET);
for (int i = 0; i < nodeList.getLength(); i++)
{
Node nNode = nodeList.item(i);
if (nNode.getNodeType() == Node.ELEMENT_NODE)
{
Element eElement = (Element) nNode;
String strTextColor = eElement.getElementsByTagName("TextColor").item(0).getTextContent();
System.out.println(strTextColor);
String strBackgroundColor = eElement.getElementsByTagName("BackgroundColor").item(0).getTextContent();
System.out.println(strBackgroundColor);
}
}
} catch (Exception e) {
e.printStackTrace();
}
}

I am able to get the text color and background color. But I don't have a clue as to how to traverse back and get the corresponding column name and add that to the map. Any help would be appreciated. Thanks in advance.

While this isn’t what you asked for, I think you would be better off using an XPath to locate each <Column> element, then reusing your XPath instance to locate the data relative to it:

public static Map<String, List<String>> getColors(Document doc) {
XPath xpath = XPathFactory.newInstance().newXPath();
try {
NodeList columns = (NodeList)
xpath.evaluate("/DynamicReport/Columns/Column", doc,
XPathConstants.NODESET);
int numColumns = columns.getLength();
Map<String, List<String>> map = new LinkedHashMap<>(numColumns);
for (int i = 0; i < numColumns; i++) {
Node column = columns.item(i);
String columnName = xpath.evaluate("ColumnName", column);
Node fontInfo = (Node) xpath.evaluate(
"FormattingInfo/Header/FontInfo", column,
XPathConstants.NODE);
String textColor =
xpath.evaluate("TextColor", fontInfo);
String backgroundColor =
xpath.evaluate("BackgroundColor", fontInfo);
map.put(columnName, Arrays.asList(textColor, backgroundColor));
}
return map;
} catch (XPathException e) {
throw new RuntimeException(e);
}
}

If you don’t pass an XPathConstants constant to XPath.evaluate, the text content of the matching node is returned, which turns out to be exactly what you want for obtaining your Strings.

If you don't mind cheesing it

Element column = (Element)(eElement.getParentNode().getParentNode().getParentNode());

> I am able to get the text color and background color. But I don't have
> a clue as to how to traverse back and get the corresponding column
> name and add that to the map.

Just evaluate this XPath expression (using your current context node that you found with this: /DynamicReport/Columns/Column/FormattingInfo/Header/FontInfo):

ancestor::Column[1]/ColumnName