Saxon XML Validation: Cannot delete XML File, when validation failed

Question

A few weeks ago I posted that issue here. Now I have a similiar problem with a different case. I created a java upload, where I wanted to check if a XML file is well formed. After the check, I want to delete it. But if the transformation failed, I cannot delete the file. I created a much easier example to run it on my local computer where I had the same issue. Please see below for my source code. You can easily copy and paste it and try it by yourself.

Did I uncover a bug, maybe the same bug I reported a few weeks before, or did I miss something in the code? I used Saxon 9.4HE.

public class TestClass 
{
public static void main (String[] args) throws Exception
{
    boolean isWellFormed = isXMLwellformed(new File("work/file.xml"));

    if(isWellFormed) System.out.println("File is well formed");
    else
    {
        System.out.println("File is not well formed");
    }
    FileUtils.deleteDirectory(new File("work"));
}

private static boolean isXMLwellformed(File file)
{
    boolean isWellformed = true;
    TransformerFactory factory = TransformerFactory.newInstance();
    StreamSource source = new StreamSource(file);
    try 
    {
        Transformer trans = factory.newTransformer();
        SAXResult sink = new SAXResult(new DefaultHandler());
        trans.transform(source, sink);
    } 
    catch (TransformerException err) 
    {
        System.err.println("Validation failed: " + err.getMessage());
        isWellformed = false;
    }
    return isWellformed;
}
}

Answer 1

Now, I find a solution that works. If I create the FileReader on my own and close it in the catch block, it works. But shouldn't it be closed automatically?

    private static boolean isXMLwellformed(File file) throws IOException
   {
    boolean isWellformed = true;
    BufferedReader br = new BufferedReader(new FileReader(file));
    TransformerFactory factory = TransformerFactory.newInstance();
    StreamSource source = new StreamSource(br);
    try 
    {
        Transformer trans = factory.newTransformer();
        SAXResult sink = new SAXResult(new DefaultHandler());
        trans.transform(source, sink);
    } 
    catch (TransformerException err) 
    {
        System.err.println("Validation failed: " + err.getMessage());
        br.close();
        isWellformed = false;
    }
    return isWellformed;
    }