public class JexlEngineUtils {
     public static BigDecimal evaluateExpression (          Map 
    
      map, String[] elementArr, String expression, int margin    ){
        JexlEngine jexl = new JexlEngine ();       JexlContext jexlContext = new MapContext ();
    

//需要set源代码Math，否则报错       jexlContext.set("Math", Math.class);

//需要set源代码 BigDecimal，否则报错

jexlContext.set("BigDecimal",BigDecimal.class);         for (String key : elementArr) {
           Object p = map.get ( key );          Double val = 0.0;          if (null != p) {
              if (p instanceof BigDecimal) {
                 BigDecimal temp = (BigDecimal) p;                val = temp.doubleValue ();             } else {
                 if (RegexUtils.isNumberWithDot ( p.toString () )) {
                    val = Double.valueOf ( p.toString () );                }             }          }          jexlContext.set ( key, val );       }       Expression e = jexl.createExpression ( expression );       Object obj = e.evaluate ( jexlContext );       BigDecimal result = new BigDecimal ( null == obj ? "0" : obj.toString () );       return result.setScale ( margin, BigDecimal.ROUND_HALF_UP );    }    //因为精度问题引入BigDecimal

public static void main(String[] args) {
        Map
    
      individualIncomeTaxMap = new HashMap<>(16);       individualIncomeTaxMap.put("cashRate",5334.4);       individualIncomeTaxMap.put("yearPremium",200000);       String[] te = {"cashRate","yearPremium"};       System.out.println(evaluateExpression(individualIncomeTaxMap,te,"Math.floor(BigDecimal.valueOf(cashRate).multiply(BigDecimal.valueOf(yearPremium).divide(BigDecimal.valueOf(1000))))",0));    } }