IN JAVA PLZ follow all
directions SHOW OUPUT! Write class PostfixEvaluator that
evaluates a postfix expression such as 6 2 + 5 * 8 4 / -
The program should read a postfix expression consisting of
single digits and operators into a StringBuilder, The program
should read the expression and evaluate it (assume it's valid). The
algorithm to evaluate a postfix expression is shown below. Use +,
-, *, /, and ^. ^ is the exponent.
Append a right parenthesis...