An infix expression suffix expression java precise implementation

Package Cn.itcast.StackAndQuen;
Import java.util.ArrayList;
Import java.util.List;

Import Java.util.Scanner;
 /** * Created by Likailong on 2016/10/16. * infix expression to suffix expression */public class Mathcaculate {public static void main (String [] args) {Scanner san=new Scanne  R (system.in);//keyboard reads list<character> list=new arraylist<> ()//infix expression into suffix expression with array storage String input
         = San.next ()//Get input information char[] Shuju = Input.tochararray ()//input all information into char array precedence of int priority=0;//mark symbol Mystack<character>mystack=new mystack<> ()//symbol precedence stack mystack<integer>caculatestack=new M
         Ystack<> ();//compute suffix expression stack int special=0;
                     for (int i=0;i<shuju.length;i++) {//The priority of each data that has reached the keyboard input for each data if (GetPriority (Shuju[i])!=0) {//)
                         if (GetPriority (Shuju[i]) >=priority&&getpriority (Shuju[i])!=3) {//If you get an operator that is compared to the top of the stack Priority=getpriority (Shuju[i]); If the stack is greater than or equal to the top priority stack
                          Mystack.push (Shuju[i]); }else if ((GetPriority (shuju[i)) ==3&&priority!=3&&special!=3) | | (GetPriority (Shuju[i])!=3&&priority==3&&special!=3)) {special=getpriority (shuju[i]), if greater than or equal to the top of the stack, and then the stack Mystack.pus
                     H (Shuju[i]); else if (getpriority (Shuju[i]) ==3&&special==3) {//If the stack is greater than or equal to the top priority stack instead
                             Out Stack while (!mystack.isempty ()) {//out stack operation Char Num=mystack.pop ();
                             List.add (num);
                         System.out.print (num);
                              } else{while (!mystack.isempty ()) {//Out of stack operation
                              Char Num=mystack.pop ();
                              List.add (num);
    System.out.print (num);                      } mystack.push (Shuju[i]);
             }else{System.out.print (Shuju[i]);//If the digital direct output is received with an array list.add (Shuju[i]);
            } while (!mystack.isempty ()) {char fuhao=mystack.pop ();
            List.add (Fuhao);
        System.out.print (Fuhao);
        } System.out.println (); for (int i=0;i<list.size (); i++) {//Operation method to traverse the string nums=list.get (i) in the presence of the suffix expression in the array. toString ();//each element is converted to a string.
            Nteger.parseint (Nums);
            Char num=list.get (i); if (num==) (' | |
            num== ') {list.remove (i);
                } if (' 0 ' <=num&&num<= ' 9 ') {//string comparison should be so written int numss=integer.parseint (nums);//String spin number
                Caculatestack.push (NUMSS);//into stack}else {int shuju1=caculatestack.pop ();/out Stack
                int Shuju2=caculatestack.pop (); Char CACUlate=list.get (i);
                int numadd=0;
                if (caculate== ' + ') {//Judge the operators in the array to perform related operations numadd=shuju1+shuju2;
                }else if (caculate== '-') {numadd= shuju2-shuju1;
                }else if (caculate== ' * ') {numadd= shuju1*shuju2;
                }else if (caculate== '/') {numadd=shuju1/shuju2;
            } caculatestack.push (Numadd); } System.out.println (Caculatestack.pop ());//get stack top element and is answer} private static int getpriority (char sh
            Uju) {//The input of each character of the priority int priority=0;
            Char Num=shuju;
                    if (0<=num&&num<=9) {}else {switch (num) {case '-':
                    Case ' + ': return priority=1;
                    Case '/': Case ' * ': return priority=2;
  Case ' (':                  Case '] ': return priority=3;
                default:priority=0;
    } return priority;
 }

}