java 实现公式或算法校验及计算

//1.引入jar 
       <!--自定义公式计算类库-->
        <dependency>
            <groupId>com.scireum</groupId>
            <artifactId>parsii</artifactId>
            <version>1.5</version>
        </dependency>

 

//2.源码如下
package com.liansheng.swap.utils;

import com.liansheng.swap.appStart.netty.server.RedisConfig;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import parsii.eval.Expression;
import parsii.eval.Parser;
import parsii.eval.Scope;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;


/**公式计算器**/
@Component
public class EquationCalculator {
    private Logger logger = LoggerFactory.getLogger(this.getClass());

    @Autowired
    private RedisUtils redisUtils;

    /**
     * 公式计算
     * @param formula
     * @return
     * @throws Exception
     */
    public double formulaCalculation(String formula) throws Exception {
//        Long start = System.currentTimeMillis();
        //去除空格
        formula = formula.replaceAll(" ","");
        /** 获取变量表 **/
        List<String> varList = getVarList(formula);
        /** 进行计算 **/
        double result = calcByParsii(formula,varList);
//        System.out.println("自定义公式计算总耗时："+(System.currentTimeMillis()-start) + "    运算结果："+result);
        return result;
    }

    /**
     * 获取变量表
     *
     * @param formula
     **/
    public static List<String> getVarList(String formula) {
        List<String> varList = new ArrayList<>();
        String str = formula;
        while (str.contains("STARTFLAG")&&str.contains("ENDFLAG")){
            int start = str.indexOf("STARTFLAG");
            int end = str.indexOf("ENDFLAG")+7;
            if(start<end){
                String ponitPara = str.substring(start,end);
                /*
                if(!varList.contains(ponitPara)){
                    varList.add(ponitPara);
                }
                */
                varList.add(ponitPara);
                str = str.substring(end);
            }
        }
        return varList;
    }
    /**
     * 公式计算
     * @param exp
     * @return
     *
     * 替代方法：calcProc
     */
    private double calcByParsii (String exp,List<String> varList) throws Exception {
        //exp  = "2 + (7-5) * 3.14159 * x + sin(0)";
        //exp = "((1+2)*2+(3-2)*3)+((1+2)/3+(2+4)/3)*2";
        // compile
        Scope scope = Scope.create();
        Expression parsiiExpr = Parser.parse(exp,scope);
        for (String key : varList) {
            Map pointInfo = redisUtils.hmget(RedisConfig.KEY_MONITOR + key.replaceAll("STARTFLAG","").replaceAll("ENDFLAG","").replaceAll("DELIMITER",":"));
            if(pointInfo!=null&&pointInfo.size()>1){
                Double value = Double.parseDouble(pointInfo.get("value").toString());
                scope.getVariable(key).setValue(value);
            }else {
                throw new RuntimeException("自定义公式:"+exp+"运算时,未获取到配置测点:"+key+"的数据");
            }
        }
        // evaluate
        double result = parsiiExpr.evaluate();
        return result;
    }


    /**
     * 公式校验
     */
    public double formulaCheck(String formula) throws Exception {
        formula = formula.replaceAll(" ","");
        if(formula.contains("ENDFLAGSTARTFLAG")){
            throw new RuntimeException("变量之间运算符！");
        }
        List<String> varList = getVarList(formula);
        double result = calcByParsiiForCheck(formula,varList);
        return result;
    }

    /**
     * 公式验证
     */
    private double calcByParsiiForCheck (String exp,List<String> varList) throws Exception {
        Scope scope = Scope.create();
        Expression parsiiExpr = Parser.parse(exp,scope);
        for (String key : varList) {
            scope.getVariable(key).setValue(1);
        }
        double result = parsiiExpr.evaluate();
        return result;
    }
}