Question

I have a function that reads from the console using readPassword(). This function is called several times in one program iteration. However, I keep getting a java io exception once it gets to the readPassword() line. I noticed when i removed the close() statement from the finally-clause this error disappears. Why does this happen and when should I properly close the reader?

public void Func()
{
        Console console = System.console();
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

        if (console == null)
            System.out.println("Error!");

        try 
        {
           char[] pwd = console.readPassword();
           String password = new String(pwd);
           System.out.println("PW: " + password);

           String input = reader.readLine();
           System.out.println("UserNm: " + input);
        } catch (IOException e) {
            System.out.println("IO EXCEPTION");
        } finally {
            if (reader != null)
            {
                try
                {
                    reader.close();
                }
                catch (IOException e)
                {
                    System.out.println("error");
                }
            }
        }
        return null;
}

Thanks in advance for the help!

Answer 1

You don’t need any reader here, just use the Console instance.

public String Func() {
        Console console = System.console();
        if (console == null)
            throw new IllegalStateException("No console available");

        try {
           String username = console.readLine("Username: ");
           String pwd = new String(console.readPassword("Password: "));
           return pwd;
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
}

Edited with your question edit. Just use the Console class, it can read/write, you don’t need any reader/writer.