使用Java Web Services技术 创建一个待办事项管理系统。不同的客户应该能够连接到一个服务器管理各种待办事项列表对象，比如查询列表项，添加列表项，删除列表项，明确待办事项列表。服务器应该也有管理功能，允许使用者进行注册。每个待办事项列的表项有一个描述、一个开始时间和一个结束时间，用户必须在规定时间内完成。用户可以添加任意数量的项目到他们的待办事项清单中；(Use Java Web Services technology to create a to-do management system. Different customers should be able to connect to a server to manage various to-do list objects, such as querying list items, adding list items, deleting list items, and specifying the to-do list. The server should also have management functions to allow users to register. Each item in the to-do list has a descr iption, a start time and an end time, which the user must complete within a specified time. Users can add any number of items to their to-do list.)