weaver-hrm-salary/src/com/engine/salary/service/impl/FormulaRunServiceImpl.java

package com.engine.salary.service.impl;

import com.engine.core.impl.Service;
import com.engine.salary.entity.datacollection.DataCollectionEmployee;
import com.engine.salary.entity.salaryformula.ExpressFormula;
import com.engine.salary.entity.salaryformula.po.FormulaVar;
import com.engine.salary.service.FormulaRunService;
import org.apache.commons.jexl3.*;

import java.util.List;

public class FormulaRunServiceImpl extends Service implements FormulaRunService {
    @Override
    public Object run(ExpressFormula expressFormula, List<FormulaVar> formulaVars, DataCollectionEmployee simpleEmployee) {

        /*
        公式内容以如下显示方式存储
         {薪资项目.输入项1}+{薪资项目.输入项2}
         */
        String formula = expressFormula.getFormula();


        JexlBuilder jexlBuilder = new JexlBuilder();
        // 创建Jexl表达式引擎
        JexlEngine jexlEngine = jexlBuilder.create();
        // 创建Jexl表达式解析器
        JexlScript jexlScript = jexlEngine.createScript(formula);
        // 创建Jexl表达式变量上下文
        JexlContext jexlContext = new MapContext();
        formulaVars.forEach(v -> {
            jexlContext.set(v.getFieldId(), v.getContent());
        });
        // 执行Jexl表达式，得到结果
        Object execute = jexlScript.execute(jexlContext);
        return execute;
    }
}