Find if the String is a number or floating point number - Regular Expression

Find if a string contains only digits?
   public static boolean stringContainsOnlyDigits(String s) {
        Pattern p = Pattern.compile( "^[0-9]+$" );
        Matcher m = p.matcher( s );
        return m.find();
    }

Find if the String is a Floating Point number. 
   public static boolean stringIsFloatingPointNumber(String s) {
        Pattern p = Pattern.compile( "^[-+]?[0-9]*\\.?[0-9]+$" );
        Matcher m = p.matcher( s );
        boolean found = m.find();
        if(found) {
            System.out.println("found: " + m.group(0));
        }
        return found;
    }

The caveat here is the strings are long text and Double.parseDouble() will be out of range. Such problems can be solved only using Regular Expressions.

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