Try-Catch: Is it OK to leave applications with handled exceptions?

I am still fairly new to programming, so there are some things I learn from observing but do not fully understand. The Try-Catch is one of these things. From what I have researched, the try statement allows me to define a block of code to be tested for errors, and the catch statement allows me to define a block of code to be executed if an error occurs in the try block.

I get that. And I have tried to use Try-Catch in situations where I was receiving exception errors that crashed my applications. The Try-Catch seemed to prevent (stop) the crashing. But here is my question, is it OK to have an application that constantly catches an exception error?

For example, I am working with EditText widget. I want the input values for the EditText to represent currency, so I applied android:inputType="numberDecimal". The issue I learned with this is that this attribute allows any number of values after the decimal. This is when I came up with an idea of updating the EditText programmically with the proper format, using something like DecimalFormat.

I am not posting my entire code, but here is the piece that I am curious about.

    @Override
    public void onTextChanged(CharSequence s, int start, int before,
            int count) {
        // TODO Auto-generated method stub

        DecimalFormat format = new DecimalFormat("0.00");

        if (etBill.getText().toString() != null && 
                etBill.getText().toString().length() > 0) {
            try {
                doubleBill = Double.parseDouble(etBill.getText().toString());
                strFormatted = format.format(doubleBill);
                Log.d(TAG, "unformatted(" + doubleBill + ")" + 
                        " // formatted(" + strFormatted + ")");

                //etBill.setText("$" + strFormatted, TextView.BufferType.EDITABLE);
                etBill.setText("$" + strFormatted);
            } catch (NumberFormatException nfe) {
                Log.e(TAG, "FloatingPointParser.parseDouble error");
            }
        } else {
            // values in editText were deleted; hardcode value
            doubleBill = 0.0;
            strFormatted = format.format(doubleBill);
        }

    }

And here is the exception error I catch every single time I input a value into my EditText widget.

So my question is, is the Try-Catch a method for me to correct my errors? Is it OK to catch exception errors, such as this NumberFormapException through the life of an application running? Am I using this right? Thanks in advance!