Strange bug with the java.io.File class

Question

Hi everibody!
I'm writting a system to upload images with JSF and RichFaces. But when i try to delete the images files sometimes hapen some strange bug.
first i'll post my method code here:
public void deleteUploadedFile(ActionEvent event) throws Throwable {
        UIComponent link = event.getComponent();
        UIParameter param = (UIParameter) link.findComponent("fileId");
        TheFile file = this.uploadedFiles.get((Integer) param.getValue());
        try {
            File f = new File(file.getPath(), file.getName());
            if ((f.exists()) && (f.canRead()) && (f.canWrite())) {
                if(f.delete()){
                    for(int i=0; i<file.getThumbs().size(); i++){
                        File t1 = new File(file.getPath(), file.getThumbs().get(i).getThumbName());
                        t1.delete();
                    setDeleted(true);
                else{
                    setDeleteLog("Arquivo não pode ser excluido");
                    setDeleted(false);
            } else {
                setDeleteLog("Erro ao tentar excluir o arquivo");
                setDeleted(false);
            this.finalize();
        } catch (Exception ex) {
            setDeleteLog("Deu erro: " + ex);
        } finally {
            if (this.deleted) {
                if (this.uploadedFiles.remove(file)) {
                    setDeleteLog("Conseguiu remover");
                } else {
                    setDeleteLog("Deu erro");
    }Well, when the method run the f.delete() line, sometimes, something strange hapen. With is, the file data is deleted as expected, but the file it self is not deleted. And even when i run the line this.finalize the JVM still using the file, with don't allows me to try to delete it untill my tomcat stop (with kill the application that was using the file). And this don't hapen every time that i try to delete one file.
And worse, once it hapen every next time that i try to delete one file hapen the same bug.
My question is...what could it be, and what can i do to solve this?!

Answer 1

About this is not a possible cause. Because before i upload a file I verify if the file already exists and even after i change the file name:
//this method change the file name and eliminate all the special characters, and also attach the current day of month,
//month, year, minute and second to the file name
public String generateFileName(String fileName){
        Locale l = new Locale("pt","BR");
        Calendar cal = Calendar.getInstance(TimeZone.getTimeZone(TimeZone.getTimeZone("GMT-3").getID()), l);
        int ext = fileName.lastIndexOf('.');
        String name = fileName.replace(fileName.substring(ext), "");
        String newName = RemoverAcentos.remover(name).toLowerCase()+cal.get(cal.DAY_OF_MONTH)+cal.get(cal.MONTH)
                +cal.get(cal.YEAR)+cal.get(cal.MINUTE)+cal.get(cal.SECOND)+fileName.substring(ext);
        return newName;
    }the upload method
String fileName = generateFileName(item.getFileName());
        try {
            File uploadFile = new File(filepath, fileName);
            if (!uploadFile.exists()) {