How to check ussd code to check balance

Question

How can I check the USSD code entered in edittext before submitting

Here I put some code, kindly helping me.

ussd_edittext.addTextChangedListener(new TextWatcher() 
{
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
                ussd_edittext.setError("Invalid password");
                ussd_ok.setEnabled(false);
            }
            public void onTextChanged(CharSequence s, int start, int before, int count) {

                if (ussd_edittext.getText().toString().trim().replaceAll("[^0-9#*]", "").length() < 4) {
                    ussd_edittext.setError("USSD code must contain * and #");
                    ussd_ok.setEnabled(false);
                }
            }
            public void afterTextChanged(Editable s) {
                Character cr = s.toString().charAt(0);
                if(s.length() < 1)
                {
                    if(!( (cr == '*') ) )
                    {   ussd_edittext.setError("USSD code must contain * and #");
                        ussd_ok.setEnabled(false);
                    }
                    else {
                        ussd_ok.setEnabled(true);
                    }
                }
                else
                {
                    String lc = s.toString().substring(0, ussd_edittext.length() - 1);
                    if(!( (cr == '*') && lc.equals("#") ) )
                    {
                        ussd_edittext.setError("USSD code must contain * and #");
                        ussd_ok.setEnabled(false);
                    }
                    else {
                        ussd_ok.setEnabled(true);
                    }
                }
            }
        });

I want to check how it should contain * and #, and also 5 digits are minimal.

Answer 1

This can help:

if (Pattern.matches("(\\*[0-9]+[\\*[0-9]+]*#)", ussd_edittext.getText().toString()) && ussd_edittext.length() >= 5) {
        //USSD code is valid
    } else {
        //USSD code is not valid
    }

Answer 2

I did something like this.

ussd_edittext.addTextChangedListener(new TextWatcher() 
{
                public void beforeTextChanged(CharSequence s, int start, int count, int after) {
                    ussd_edittext.setError("Invalid password");
                    ussd_ok.setEnabled(false);
                }
               public void onTextChanged(CharSequence s, int start, int before, int count) {    
                    if (ussd_edittext.getText().toString().trim().length() < 4 && ( ! t.contains(""+ussd_edittext))) {
                        ussd_edittext.setError("USSD code must contain * and #");
                        ussd_ok.setEnabled(false);
                    }
                }

                @Override
                public void afterTextChanged(Editable s)
                {
                    if (ussd_edittext.getText().toString().trim().length() > 4)
                    {
                        Character fc = ussd_edittext.getText().toString().charAt(0);    
                        String lc = ussd_edittext.getText().toString().substring(ussd_edittext.length() - 1);
                        if(!((fc == '*') && lc.equals("#")))
                        {
                            ussd_edittext.setError("USSD code must contain * and #");
                            ussd_edittext.requestFocus();
                        }
                        else
                        {                      ussd_ok.setEnabled(true);               }
                    }
                    else
                    {                        ussd_edittext.setError("USSD code must contain * and #");                 }
                }
            });