Question

I followed this tutorial for uploading a file in my JSF2 application.
The application works fine but I am unhappy with one aspect.
While rebuilding the request, the File sent via request is saved somewhere on the disk.

Even though the file is saved I need to rename the file with a name which is available after entering the Managed Bean containing the action method.

Therefore I decided to create a new file with de desired name, copy the already saved file, and then delete the unneeded one.

private File uploadFile;
//...
try {
    BufferedWriter bw = new BufferedWriter(new FileWriter(newFile));
    BufferedReader br = new BufferedReader(new FileReader(uploadFile));

    String line = "";
    while ((line = br.readLine()) != null){
        bw.write(line);
    }
} catch (Exception e){}

The new file appears in the desired location but this error is thrown when I’m trying to open the file: “Invalid or unsupported PNG file”

These are my questions:

1. Is there a better way to solve this problem?
2. Is this solution the best way to upload a picture? Is there a reason to save the file before the business logic when there may be need to resize the picture or the desired name is not available yet.

LE:
I know abot this tutorial as well but I’m trying to do this mojarra only.

Answer 1

Don’t use Reader and Writer when you deal with binary files like images. Use streams: FileInputStream and FileOutputStream. And the best variant is to use @Perception solution with renameTo method.

Readers read file as if it consists of characters (e.g. txt, properties, yaml files). Image files are not characters, they are binary and you must use streams for that.