What do files deleted by groovy leave behind in Windows 7? - eclipse

Question

I have a groovy script that saves multiple files from a remote directory to my temp directory and parses them into xml. It has an interesting bug. Each time it runs, it can't find one file in my temp directory. The next time it runs, it finds that file, but can't find a new file. If I have 20 files, it won't find all 20 files until the 20th run. The temp directory is cleared after each run. I'm wondering if there are other artifacts the program is leaving behind?
If I clean the project after 16 runs, it still finds the first 16 files. So it seems it's not an artifact in eclipse.
This is running in Eclipse 3, Java 1.5, Windows 7, Groovy 1.0.
remoteftpFile.findAll {
println "in find"
ftp.getReply();
it.isFile()
}.each {
println "in each"
ftp.getReply();
println it
ftp.getReply();
def tempDestination=PropertiesUtil.getTempDir()
def procDestination=PropertiesUtil.getProcessedDir()
def tempFile = new File(tempDestination+ it.name )
def procFile = new File(procDestination+ it.name )
//set it to delete
ftp.getReply();
println "got tempfile"
def localftpFile = ftp.SaveToDisk(it,tempFile) //Save each file to disk
//************** Handles decryption via gpgexe
println "Decrypting file";
println localftpFile.toString();
def localftpFileStr=localftpFile.toString();
def processedftpFileStr=procFile.toString();
def gpgstring=PropertiesUtil.getGpgString();
def decryptedOutputName = localftpFileStr.substring(0, (localftpFileStr.length()-4));
def decryptedProcOutputName= processedftpFileStr.substring(0, (processedftpFileStr.length()-4));
def decryptedOutputXMLName = decryptedOutputName.substring(0, (decryptedOutputName.length()-4))+".xml";
def decryptedProcOutputXMLName = decryptedProcOutputName.substring(0, (decryptedProcOutputName.length()-4))+".xml";
println decryptedOutputName;
def xmlfile = new File(decryptedOutputName)
def cdmpXmlFile = new File(decryptedOutputXMLName)
def procCdmpXmlFile = decryptedProcOutputXMLName
println gpgstring + " --output ${decryptedOutputName} --decrypt ${localftpFile} "
(new ExternalExecute()).run(gpgstring +" --output ${decryptedOutputName} --decrypt ${localftpFile} ");
Thread.sleep(1000);
//************* Now Parse CSV file(s) into xml using stack overflow solution
println "parsing file"
def reader = new FileReader(xmlfile)
def writer = new FileWriter(cdmpXmlFile)
def csvdata = []
xmlfile.eachLine { line ->
if (line){
csvdata << line.split(',')
}
}
def headers = csvdata[0]
def dataRows = csvdata[1..-1]
def xml = new groovy.xml.MarkupBuilder(writer)
// write 'root' element
xml.root {
dataRows.eachWithIndex { dataRow, index ->
// write 'entry' element with 'id' attribute
entry(id:index+1) {
headers.eachWithIndex { heading, i ->
// write each heading with associated content
"${heading}"(dataRow[i])
}
}
}
}
println "Performing XSL Translation on ${cdmpXmlFile}"
def cdmpXML = new XMLTransformer(xmlTranslate).run(cdmpXmlFile) //Run it on each of the xml files and set the output
new File("C:\\temp\\temp.xml").write(cdmpXML)
new File(procCdmpXmlFile).write(cdmpXML)
println "Done Performing XSL Translation"
println "Uploading Data to CDMP"
def cdmpUp = new UpdateCDMP(updateDB)
cdmpUp.run(cdmpXML)
println "Finished Upload and Import"
//do clean-up backing it up AND removing the files
println "Finished"
println "Closing Buffers"
reader.close();
writer.close();
println "Deleting Local Files"
new File(decryptedOutputName).deleteOnExit();
new File(localftpFile).deleteOnExit();
xmlfile.deleteOnExit();
cdmpXmlFile.deleteOnExit();
println "Deleting " + cdmpXmlFile.getName()
new File("C:\\temp\\temp.xml").deleteOnExit();
}
ftp.close()
}

Answer 1

This is because you are using deleteOnExit, which is not guaranteed to delete a file. It only deletes if:
the files are closed correctly,
the JVM exits correctly (with no exceptions), and
a System.exit() was called with 0 argument (or the VM terminated naturally).
It's especially problematic on Windows OSes. I can't point to a specific Stack Overflow question about this, but most questions involving deleteOnExit discuss this issue.
If you actually want to delete a file, then you should always use aFile.delete() directly. There is really no good reason to delay the deletion until later in your example.