//定义字符串

String str = "1,3,6,9,4,2,1,6";

//截取字符串

String[] strArr = str.split(",");

//转换long类型的数组

long[] strArrNum = (long[]) ConvertUtils.convert(strArr,long.class);

       public Map<String, Object> saveRoleSet(String roleIds, Long userId) {

        Map<String, Object> resultMap = new HashMap<>();

        roleService.delete(userId); //根据用户id删除所有用户角色关联实体

        if (!StringUtils.isEmpty(roleIds)) {

            String idsStr[] = roleIds.split(",");
long rIds[] = (long[])ConvertUtils.convert(idsStr,long.class);

            userRoleService.setRoles(userService.get(userId),rIds);

        }