算符优先法 设计一个带（）的计算器解决方法

import java.util.Stack;public class Calcu{    Stack <Integer>num;    Stack <String>exp;    String expression="7+(8+2*2)/3-1=";    public Calcu(){        num=new Stack<Integer>();        exp=new Stack<String>();    }    public void calculate(){        char t;        int s;        int len=expression.length();        for(int i=0;i<len;i++){            t=expression.charAt(i);            switch(t){            case '-':            case '+':if(!exp.empty()&& !exp.peek().equals("(") && !exp.peek().equals(")")){                s=compute(exp.pop());                num.push(s);            } exp.push(String.valueOf(t));            break;            case '/':            case '*':                if(!exp.empty()&& exp.peek().equals("/")){                    s=compute(exp.pop());                    num.push(s);                }else if(!exp.empty() && exp.peek().equals("*")){                    s=compute(exp.pop());                    num.push(s);                }                exp.push(String.valueOf(t));break;            case '(':exp.push(String.valueOf(t));break;            case ')':{                while(!exp.peek().equals("(")){                    s=compute(exp.pop());                    num.push(s);                }                exp.pop();                break;            }            case '=':{                while(!exp.empty()){                    s=compute(exp.pop());                    num.push(s);                }                System.out.println(num.pop());                break;            }            default:num.push(t-48);        }    }}    private int compute(String exp){        int n2=num.pop();        int n1=num.pop();        switch(exp.charAt(0)){        case '+':return n1+n2;        case '-':return n1-n2;        case '*':return n1*n2;        case '/':return n1/n2;        }        return -1;    }    public static void main(String args[]){        Calcu c=new Calcu();        c.calculate();    }}
------解决方案--------------------
给你逆波兰式算法.经过测试


package expression;   
   
import java.io.*;   
import java.util.*;   
   
public class Expression {   
   private ArrayList expression = new ArrayList();// 存储中序表达式   
   
   private ArrayList right = new ArrayList();// 存储右序表达式   
   
   private String result;// 结果   
   
   // 依据输入信息创建对象，将数值与操作符放入ArrayList中   
   private Expression(String input) {   
       StringTokenizer st = new StringTokenizer(input, "+-*/()", true);   
       while (st.hasMoreElements()) {   
           expression.add(st.nextToken());   
       }   
   }   
   
   // 将中序表达式转换为右序表达式   
   private void toRight() {   
       Stacks aStack = new Stacks();   
       String operator;   
       int position = 0;   
       while (true) {   
           if (Calculate.isOperator((String) expression.get(position))) {   
               if (aStack.top == -1  
                       || ((String) expression.get(position)).equals("(")) {   
                   aStack.push(expression.get(position));   
               } else {   
                   if (((String) expression.get(position)).equals(")")) {   
                       if (!((String) aStack.top()).equals("(")) {   
                           operator = (String) aStack.pop();   
                           right.add(operator);   
                       }   
                   } else {   
                       if (Calculate.priority((String) expression