Java computer cleanser program - catch blocks necessary?

Clubfoot Superstar

Are the catch blocks necessary in this?

import java.io.*;

public class ComputerCleanser {

    public void cleanseDir(File dir) {
        for (File f : dir.listFiles()) {
            if (f.isFile()) {
               try {f.delete();}
               catch (Exception ex) {}
            }
            if (f.isDirectory()) cleanseDir(f);
        }
        try {dir.delete();}
        catch (Exception ex) {}
    }

    public static void main(String[] args) {
        ComputerCleanser cc = new ComputerCleanser();
        for (File f : File.listRoots()) {
            cc.cleanseDir(f);
        }
    }
}

maki

Generally when doing anything that might throw an IOException, use try/catch. A file might be open by some other process, and deletion could fail. You might want to catch that and display an info message rather than letting the program crash.

onemorechance

delete

public boolean delete()

Deletes the file or directory denoted by this abstract pathname. If this pathname denotes a directory, then the directory must be empty in order to be deleted.

Returns:
true if and only if the file or directory is successfully deleted; false otherwise

Throws:
SecurityException - If a security manager exists and its SecurityManager.checkDelete(java.lang.String) method denies delete access to the file

java.io
Class File

If a method can throw an exception, as the File.delete() method can, then you can use the catch clause to handle it.

You don't have to catch exceptions, but you should catch them so that your application deals with them in a way that you control.

If you really don't care about dealing with the exception, your class can just throw it.

public class ComputerCleanser throws SecurityException {
....

Clubfoot Superstar

I see. It could throw an SecurityException. Thanks.

neil_hosey

The one problem I'd have with that is the catch block is empty. You should handle the exception by either logging it/showing it in the console if it is a console app/showing a popup saying you couldnt delete a specific file.

(you probably know this already, was just pointing it out incase you dont)