The following piece of code won't accept any keyboard input:

        NumberFormat nf = NumberFormat.getCurrencyInstance();
        NumberFormatter nfr = new NumberFormatter(nf);
        nfr.setAllowsInvalid(false);
        nfr.setOverwriteMode(true);
        JFormattedTextField jftf = new JFormattedTextField(nfr);

This code should allow users to edit currency amounts in the JFormattedTextField. For example in Germany locale, if the user inputs "1000", it should accept it and display "1,000.00 €".

The similar behavior is observed with a percent format, which is already reported in the bug 6462562.