jexl表达式解析

1.引入依赖包

<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-jexl --> <!--jexl解析表达式--> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-jexl3</artifactId> <version>3.1</version> </dependency>

2.上代码

public class ExpressionUtil { /** * @description: 表达式解析并计算并返回BigDecimal类型计算结果 * @param * @return * @author GMH * @date 2020/7/1 14:12 */ public static BigDecimal executeExpressionBigDecimal(String eval, Map<String, Object> map){ Object object = executeExpression(eval, map); return BigDecimal.valueOf(Double.valueOf(Objects.toString(object,"0"))); } /** * @description: 根据表达式和参数集合进行计算 * @param eval "day+1" * @param map "key:day,value:31" * @return "32" * @author GMH * @date 2020/7/1 14:08 */ private static Object executeExpression(String eval, Map<String, Object> map) { JexlExpression expression = new Engine().createExpression(eval); JexlContext context = new MapContext(); if (Objects.nonNull(map)) { map.forEach(context::set); } return expression.evaluate(context); } public static void main(String[] args) { Map<String,Object> map = new HashMap<>(); map.put("landArea",10100); map.put("transactionPrice",10000); String eval = "landArea > 1000 ? transactionPrice * 0.5 : transactionPrice * 1"; BigDecimal res = executeExpressionBigDecimal(eval,map); System.out.printf(res.toString()); } }

3.测试输出结果