I haven't used remote debugging but, as Tomcat is actually running the code on the remote system, it will not be treating it as a Windows file. The debug client being on a Windows system will not affect that. It might affect the display of file paths, though. If the filePath parameter has forward slashes, then it will still have forward slashes when the "new File(filePath)" statement is executed, since it is just a String, with no file path behaviour. If you're viewing the "file" variable, then the local system may be displaying the file with Windows path separators. This suggests that the file does not exist, at least at the implied path. Maybe it isn't looking for the file in quite the location you expect?