一个简单的公式计算工具类

import java.math.BigDecimal;import java.util.*;/** * 简略的公式计算工具，仅反对+ 、-、*、/、（） * @author ningyongli * @date 2020-07-13 */public class CalculateUtils {    private static final Map<String, Integer> PRIORITY_MAP = new HashMap<>();    private static final List<String> OPERATOR_LIST = new ArrayList<>();    static {        PRIORITY_MAP.put("(", 0);        PRIORITY_MAP.put("+", 5);        PRIORITY_MAP.put("-", 5);        PRIORITY_MAP.put("*", 10);        PRIORITY_MAP.put("/", 10);        PRIORITY_MAP.put(")", 15);        OPERATOR_LIST.add("+");        OPERATOR_LIST.add("-");        OPERATOR_LIST.add("*");        OPERATOR_LIST.add("/");        OPERATOR_LIST.add("(");        OPERATOR_LIST.add(")");    }    /**     * 计算入口，除法计算小数位为16位     * @param data 数据     * @param express 公式     * @return  BigDecimal 计算结果     */    public static String execute(Map<String, String> data, String express) {        express = express.replaceAll("\\s", "");        List<String> expressWordArr = split(express);        Stack<String> dataStack = new Stack<>();        Stack<String> operatorStact = new Stack<>();        for (String expressWord : expressWordArr) {            if (!OPERATOR_LIST.contains(expressWord)) {                dataStack.push(expressWord);            } else {                if (operatorStact.isEmpty()) {                    operatorStact.push(expressWord);                } else {                    if ("(".equals(expressWord)) {                        operatorStact.push(expressWord);                    } else if (")".equals(expressWord)) {                        // 括号内计算;                        operatorStact.push(expressWord);                        dalRightBracket(dataStack, operatorStact, data);                    } else {                        // 加减乘除                        calculate(dataStack, operatorStact, expressWord, data);                    }                }            }        }        while (!operatorStact.empty()) {            String operator = operatorStact.pop();            dal(dataStack, operator, data);        }        return data.get(dataStack.pop());    }    /**     * 解析关键词     * @param express 公式     * @return List<String> 拆分后的公式     */    private static List<String> split(String express) {        List<String> list = new ArrayList<>();        StringBuilder builder = new StringBuilder();        for (int i = 0; i < express.length(); i++) {            char c = express.charAt(i);            if (!OPERATOR_LIST.contains(String.valueOf(c))) {                builder.append(c);            } else {                list.add(builder.toString());                builder.delete(0, builder.length());                list.add(String.valueOf(c));            }            if (i == (express.length() - 1)) {                if (builder.length() > 0) {                    list.add(builder.toString());                }            }        }        return list;    }    /**     * 括号内计算     * @param dataStack 数据栈     * @param operatorStact 操作栈     * @param s 操作符     * @param data 数据     */    private static void calculate(Stack<String> dataStack, Stack<String> operatorStact, String s, Map<String, String> data) {        String oldOp = operatorStact.peek();        int oldOpNum = PRIORITY_MAP.get(oldOp);        int currentNum = PRIORITY_MAP.get(s);        if (oldOpNum >= currentNum) {            dal(dataStack, oldOp, data);            operatorStact.pop();            if (operatorStact.isEmpty()) {                operatorStact.push(s);            } else {                calculate(dataStack, operatorStact, s, data);            }        } else {            operatorStact.push(s);        }    }    /**     * 括号内计算     * @param dataStack 数据栈     * @param operatorStact 操作栈     * @param data 数据     */    private static void dalRightBracket(Stack<String> dataStack, Stack<String> operatorStact, Map<String, String> data) {        while ( !operatorStact.empty() && ")".equals(operatorStact.peek())) {            String rightBracket = operatorStact.pop();            String tempOp = operatorStact.peek();            if ("(".equals(tempOp)) {                operatorStact.pop();            } else {                dal(dataStack, tempOp, data);                operatorStact.pop();                operatorStact.push(rightBracket);            }        }    }    /**     * 根底计算     * @param dataStack 数据栈     * @param operator 操作符     * @param data 数据     */    private static void dal(Stack<String> dataStack, String operator, Map<String, String> data) {        String temp = dataStack.pop();        String oldTemp = dataStack.pop();        BigDecimal tempValue;        BigDecimal tempBigDecimal = new BigDecimal(data.get(temp));        BigDecimal oldTempBigDecimal = new BigDecimal(data.get(oldTemp));        switch (operator) {            case "+":                tempValue = oldTempBigDecimal.add(tempBigDecimal);                break;            case "-":                tempValue = oldTempBigDecimal.subtract(tempBigDecimal);                break;            case "*":                tempValue = oldTempBigDecimal.multiply(tempBigDecimal);                break;            case "/":                tempValue = oldTempBigDecimal.divide(tempBigDecimal, 16, BigDecimal.ROUND_HALF_UP);                break;            default:                throw new BaseRunTimeException("不反对的计算操作");        }        String uuid = String.valueOf(UUID.randomUUID());        data.put("tempValue-" + uuid, tempValue.toString());        dataStack.push("tempValue-" + uuid);    }}

一个简略的公式计算，有须要的能够参考一下