表达式计算java实现

import java.util.LinkedList;public class Calc {LinkedList operList = new LinkedList();LinkedList numList = new LinkedList();String oper1 = "+-";String oper0 = "*/";/** * @param args */public static void main(String[] args) {String exp = "(32/((8+2)-6)-6)*3";Calc c = new Calc();try {System.out.println(c.calc(c.replceKuoHao(exp)));} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}// System.out.println(c.calc(exp));}// 有括号，先计算括号里边的.括号不作为运算符public String replceKuoHao(String exp1) throws Exception {StringBuffer exp = new StringBuffer(exp1);if (exp.indexOf("(") > -1) {if (exp.indexOf(")") < 0) {throw new Exception("Expressation format error, loss KuoHao!");} else {while (exp.indexOf("(") > -1) {int right = exp.indexOf(")");// System.out.println(right);int left = exp.lastIndexOf("(", right);// System.out.println(left);String temp = exp.substring(left, right + 1);int result = calc(temp.substring(1, temp.length() - 1));exp = exp.replace(left, right + 1, String.valueOf(result));}}}return exp.toString();}public int calc(String exp) {String endOper = "#";int result = 0;if (!exp.endsWith(endOper)) {exp = exp + endOper;}StringBuffer buffer = new StringBuffer();for (int i = 0; i < exp.length(); i++) {// 结束符if ('#' == exp.charAt(i)) {// 计算所有Integer curNum = Integer.valueOf(buffer.toString());while (operList.size() > 0) {result = specificCacl(result, curNum);curNum = new Integer(result);}}// 如果是运算符if (this.isOperator(exp.charAt(i))) {if (operList.size() == 0) {this.operList.addLast(String.valueOf(exp.charAt(i)));this.numList.addLast(Integer.valueOf(buffer.toString()));} else {Integer curNum = Integer.valueOf(buffer.toString());while (operList.size() > 0) {// 进行运算符优先级比较if (this.compareTo(this.operList.getLast().toString().charAt(0), exp.charAt(i))) {result = specificCacl(result, curNum);curNum = new Integer(result);} else {break;}}operList.addLast(String.valueOf(exp.charAt(i)));numList.addLast(curNum);}// 重ibuffer = new StringBuffer();} else {buffer.append(exp.charAt(i));}}return result;}private int specificCacl(int result, Integer curNum) {// 获取前一个操作数和运算符进行计算char preOper = operList.removeLast().toString().charAt(0);Integer preNum = Integer.valueOf(numList.removeLast().toString());switch (preOper) {case '+':result = curNum.intValue() + preNum.intValue();break;case '-':result = preNum.intValue() - curNum.intValue();break;case '*':result = preNum.intValue() * curNum.intValue();break;case '/':result = preNum.intValue() / curNum.intValue();break;}// curNum = new Integer(result);return result;}public boolean isOperator(char op) {if ("+-*/".indexOf(op) > -1) {return true;}return false;}public boolean compareTo(char a, char b) {if (this.oper0.indexOf(a) > -1) {return true;} else if (this.oper0.indexOf(b) > -1) {return false;} else {return true;}}}