I manage a Tomcat/JSP webapp. We are updating our source code to conform
to the recent `javax` -> `jakarta` namespace change in the Servlet package.
The app uses the Apache Commons FileUpload package, which must be upgraded
from v1 to v2 as part of this change.
FileUpload v1 contains a `DiskFileItem` class:
```
org.apache.commons.fileupload.disk.DiskFileItem
```
FileUpload v2 contains the corresponding class
```
org.apache.commons.fileupload2.core.DiskFileItem
```
Our webapp code, written for v1, extends `DiskFileItem`:
```
public class MonitoredDiskFileItem extends DiskFileItem
{
private MonitoredOutputStream mos = null;
private OutputStreamListener listener;
public MonitoredDiskFileItem(String fieldName, String contentType,
boolean isFormField, String fileName, int sizeThreshold, File repository,
OutputStreamListener listener)
{
super(fieldName, contentType, isFormField, fileName, sizeThreshold,
repository);
this.listener = listener;
}
public OutputStream getOutputStream() throws IOException
{
if (mos == null)
{
mos = new MonitoredOutputStream(super.getOutputStream(),
listener);
}
return mos;
}
}
```
This breaks with the update to v2 with `error: cannot inherit from final
DiskFileItem` because the `DiskFileItem` class was changed to `final`
across versions.
The migration guide at
https://commons.apache.org/proper/commons-fileupload/migration.html doesn't
give guidance at this level of detail.
Is there anything I can do to salvage this code? I know that I could
compile my own version of the source code without the `final` keyword in
`DiskFileItem.class`, but I have to assume there's a reason for it and that
it would break other aspects of the code. I hope very much that there's a
simpler solution. I'm a system administrator, not a programmer, so I
cannot rewrite the package from scratch.
Thanks,
Joel
