File download/code

Question

Hello,
I'm using JDeveloper 11.1.1.3. I'm trying to read the value of an attribute in an "ADF Quick Query with Table" called "Filename" and compare it with list of files i have in the directory "C:\\demos". Once the value is matched, the file with the corresponding Filename should be download. However, when i press the download button which has an af:downloadActionlistener binded to my bean i get an empty page. Can anyone please check my code:
public void ACDownloadFile(FacesContext facesContext, OutputStream outputStream)
            InputStream in;
            BindingContainer bindings = BindingContext.getCurrent().getCurrentBindingsEntry();
            DCIteratorBinding dciter = (DCIteratorBinding) bindings.get("SearchAdministrationCircularsView1Iterator");
            Row selectedrow = dciter.getCurrentRow();
            File root = new File("C:\\demos");
            String att = "";
            if (selectedrow != null) {
                att = (String)selectedrow.getAttribute("Filename");
              File[] listOfFiles = root.listFiles();
              for(int i = 0; i < listOfFiles.length; i++){
                  String filename = listOfFiles.getName();
if(filename.equalsIgnoreCase(att)){//attname  
try {
in = new FileInputStream(listOfFiles[i]);
IOUtils.copy(in, outputStream);
in.close();
outputStream.flush();
catch (IOException e)
e.printStackTrace();
FacesMessage msg = new FacesMessage(FacesMessage.SEVERITY_ERROR, e.getMessage(), "");
FacesContext.getCurrentInstance().addMessage(null, msg);
i=listOfFiles.length;
}Thanks,
Mohamed                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   

Answer 1

Mohamed,
the code look OK. One thing which you can do better is not to iterate over all files present in the directory, but use the File.exists(); method with the file name you are getting from the UI.
If the file exisits you get true as return value otherwise false.
File root = new File("C:\\demos");
            String att = "";
            if (selectedrow == null) {
                return;
            att = (String)selectedrow.getAttribute("Filename");
            File downloadFile = new File("C:\\demos\\"+attr);
            if (!downloadFile.exists()) {
                return;
            try {
                in = new FileInputStream(listOfFiles);
IOUtils.copy(in, outputStream);
in.close();
outputStream.flush();
catch (IOException e) {
e.printStackTrace();
FacesMessage msg = new FacesMessage(FacesMessage.SEVERITY_ERROR, e.getMessage(), "");
FacesContext.getCurrentInstance().addMessage(null, msg);
Should do the it. To avoid problems the the case the file name is given from the UI you should store all files in upper or lowercase.
The there are some other flaws in your code like you test in the file name is given from the UI, but if it's not you still iterate over all files. Next you don't stop the iteration of the files once you found the matching file.
Have you debug the code and verified that the fileyou are looking for is found?
Timo