src/org/nutz/validate/NutValidate.java
public Object check(Object val) throws NutValidateException {
        Object re = val;
        for (NutValidator nv : items) {
            re = nv.check(re);
        }
        return re;
    }
public Object check(Object val) throws NutValidateException {
        Object re = val;
        for (NutValidator nv : items) {
            re = nv.check(re);
        }
        return re;
    }
执行检查

@param val
@return 检查后的结果，可能会被修改，譬如 `trim` 操作
@throws NutValidateException
- 如果任何一个检查器除了错误，就会抛出本错误，并中断后续的检查