MVEL自定义表达式反复掉用报错：duplicate function

起因：第一次调用时会将function缓存，再次调用时提醒函数反复

计划：先将funciton放入缓存，再次调用时间接调用申明缓存中的函数

  • 自定义函数名，不要与参数名雷同

示例代码：

@RunWith(SpringRunner.class)@SpringBootTestpublic class MvelTest {            @Test    public void evalTest(){        //表达式        String roundup = "def roundup(num) { roundnum = null; if(num != null){ int roundnum = Math.round(num); } return roundnum; }";        VariableResolverFactory functionFactory = new MapVariableResolverFactory();        MVEL.eval(roundup, functionFactory);        VariableResolverFactory resolverFactory = new MapVariableResolverFactory();        resolverFactory.setNextFactory(functionFactory);        Map<String, Object> map = new HashMap<String, Object>();        map.put("A", new BigDecimal(2.33));        map.put("B", new BigDecimal(4));        String exp = "roundup(A*B)";        System.out.println(MVEL.eval(exp, map, resolverFactory));        System.out.println("------------");        VariableResolverFactory resolverFactory2 = new MapVariableResolverFactory();        resolverFactory2.setNextFactory(functionFactory);        Map<String, Object> map2 = new HashMap<String, Object>();        map2.put("A", new BigDecimal(3.33));        map2.put("B", new BigDecimal(2));        System.out.println(MVEL.eval(exp, map2, resolverFactory2));    }}

错误代码示例

向缓存中退出roundup函数

第一次执行胜利

再次调用再次向缓存中退出roundup函数

VariableResolverFactory中存在函数抛出异样