ssm写一个通知公告的代码

首先，需要创建一个通知公告的实体类，例如：

public class Notice {
    private Integer id;
    private String title;
    private String content;
    private Date createTime;
    // getter和setter方法省略
}

接着，需要创建一个数据访问层接口和实现类：

public interface NoticeMapper {
    int insert(Notice notice);
    int update(Notice notice);
    int delete(Integer id);
    Notice selectById(Integer id);
    List<Notice> selectAll();
}

@Repository
public class NoticeMapperImpl implements NoticeMapper {
    @Autowired
    private JdbcTemplate jdbcTemplate;

    @Override
    public int insert(Notice notice) {
        String sql = "INSERT INTO notice(title, content, create_time) VALUES (?, ?, ?)";
        return jdbcTemplate.update(sql, notice.getTitle(), notice.getContent(), notice.getCreateTime());
    }

    @Override
    public int update(Notice notice) {
        String sql = "UPDATE notice SET title=?, content=?, create_time=? WHERE id=?";
        return jdbcTemplate.update(sql, notice.getTitle(), notice.getContent(), notice.getCreateTime(), notice.getId());
    }

    @Override
    public int delete(Integer id) {
        String sql = "DELETE FROM notice WHERE id=?";
        return jdbcTemplate.update(sql, id);
    }

    @Override
    public Notice selectById(Integer id) {
        String sql = "SELECT * FROM notice WHERE id=?";
        return jdbcTemplate.queryForObject(sql, new BeanPropertyRowMapper<>(Notice.class), id);
    }

    @Override
    public List<Notice> selectAll() {
        String sql = "SELECT * FROM notice";
        return jdbcTemplate.query(sql, new BeanPropertyRowMapper<>(Notice.class));
    }
}

然后是服务层接口和实现类：

public interface NoticeService {
    void addNotice(Notice notice);
    void updateNotice(Notice notice);
    void deleteNotice(Integer id);
    Notice getNoticeById(Integer id);
    List<Notice> getAllNotices();
}

@Service
public class NoticeServiceImpl implements NoticeService {
    @Autowired
    private NoticeMapper noticeMapper;

    @Override
    public void addNotice(Notice notice) {
        noticeMapper.insert(notice);
    }

    @Override
    public void updateNotice(Notice notice) {
        noticeMapper.update(notice);
    }

    @Override
    public void deleteNotice(Integer id) {
        noticeMapper.delete(id);
    }

    @Override
    public Notice getNoticeById(Integer id) {
        return noticeMapper.selectById(id);
    }

    @Override
    public List<Notice> getAllNotices() {
        return noticeMapper.selectAll();
    }
}

最后是控制层的代码，可以使用SpringMVC框架来实现：

@Controller
@RequestMapping("/notice")
public class NoticeController {
    @Autowired
    private NoticeService noticeService;

    @GetMapping("/list")
    public String getNoticeList(Model model) {
        List<Notice> noticeList = noticeService.getAllNotices();
        model.addAttribute("noticeList", noticeList);
        return "noticeList";
    }

    @GetMapping("/add")
    public String addNoticePage() {
        return "addNotice";
    }

    @PostMapping("/add")
    public String addNotice(Notice notice) {
        noticeService.addNotice(notice);
        return "redirect:/notice/list";
    }

    @GetMapping("/edit/{id}")
    public String editNoticePage(@PathVariable("id") Integer id, Model model) {
        Notice notice = noticeService.getNoticeById(id);
        model.addAttribute("notice", notice);
        return "editNotice";
    }

    @PostMapping("/edit")
    public String editNotice(Notice notice) {
        noticeService.updateNotice(notice);
        return "redirect:/notice/list";
    }

    @GetMapping("/delete/{id}")
    public String deleteNotice(@PathVariable("id") Integer id) {
        noticeService.deleteNotice(id);
        return "redirect:/notice/list";
    }
}

以上代码实现了通知公告的添加、编辑、删除和查询功能。其中，addNoticePage、addNotice、editNoticePage、editNotice和deleteNotice方法对应了添加、编辑、删除和查询的页面和请求。需要在SpringMVC的配置文件中配置视图解析器和静态资源映射。