Need Java code for the following question:

Ratings will be given to correct answer, thank you!
Complete programming assignment number 4, Prefix Calculator, on page 1350 Write a program that allows the user to enter prefix expression in a text field. The program reads the expression, evaluates it, and displays the prefix expression into a binary tree before evaluating it. Use the prefix expressions and the values below for testing. Expressions 12 +2 51 Result Values 12 53 35
PayPal Gateway not configured
PayPal Gateway not configured