项目——通过自动回复机器人学MyBatis(一)

程序员文章站 2022-06-08 13:02:40

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这是我在慕课网学习此课程的课后回顾与总结

课程地址:http://www.imooc.com/learn/154

项目前端页面示例:

后端管理页面示例:

list.jsp

项目技术栈:

前期还是用JDBC，后面会用Mybatis，这样能更好更清晰的认识到Mybatis与JDBC的差别和好处

项目目录:

项目——通过自动回复机器人学MyBatis(一)

JavaBean：Message类

public class Message {
	
	private String id;         //主键
	
	private String command;     //命令名称
	
	private String description;  //命令描述
	
	private String content;     //命令回复内容
        get、set方法略.......

MessageDao类

public class MessageDao {
	
	public List<Message> queryMessageList(String command,String description){
			List<Message> messageList=new ArrayList<Message>();
			try {
				Class.forName("com.mysql.jdbc.Driver");
				Connection conn=DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/we_chat","root","root");
				StringBuilder sql=new StringBuilder("select id,command,description,content from message where 1=1");
				
				List<String> paramList=new ArrayList<String>();
				if(command!=null&&!"".equals(command.trim())){
					sql.append(" and command=?");
					paramList.add(command);
				}
				if(description!=null&&!"".equals(description.trim())){
					sql.append(" and description like '%' ? '%'");
					paramList.add(description);
				}
				PreparedStatement pre=conn.prepareStatement(sql.toString());
				for(int i=0;i<paramList.size();i++){
					pre.setString(i+1, paramList.get(i));
				}
				ResultSet rs=pre.executeQuery();
				
				
				while(rs.next()){
					Message message=new Message();
					message.setId(rs.getString("id"));
					message.setCommand(rs.getString("command"));
					message.setContent(rs.getString("content"));
					message.setDescription(rs.getString("description"));
					messageList.add(message);
				}
				
			} catch (Exception e) {
				e.printStackTrace();
			}
			return messageList;
	
	}
}

ListService类

public class ListService {
	
	public List<Message> queryMessageList(String command,String description){
		MessageDao messageDao=new MessageDao();
		return messageDao.queryMessageList(command, description);
	}
}

ListServlet类

public class ListServlet extends HttpServlet {

	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		//设置编码
		req.setCharacterEncoding("UTF-8");
		
		String command=req.getParameter("command");
		String description=req.getParameter("description");
		//向页面传值
		req.setAttribute("command", command);
		req.setAttribute("description", description);
		
		ListService listService=new ListService();
		req.setAttribute("messageList", listService.queryMessageList(command, description));
		
		req.getRequestDispatcher("/WEB-INF/jsp/back/list.jsp").forward(req,resp);
	}

	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		// TODO Auto-generated method stub
		this.doGet(req, resp);
	}
	
}