3/23团队作业 最短路径查询

所花时间：3小时

代码量：如下：

博客量：本学期截至目前26

了解到的知识点：最短路径查询

在今天在网上搜索了一下最短路径的代码并且问别的同学，然后我和我的cp完成了这项功能的实现，但是还是不太完整。

部分代码如下：

因为没用sevlet 所以就在jsp文件中写了。

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8"%>
<%@ page import="java.sql.*"%>
<%@ page import="Util.util" %>
<jsp:useBean id="util" class="Util.util"></jsp:useBean>
<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>Insert title here</title>
    </head>
    <body>
        <h1> 起点与终点途径站点</h1>

        </body>
            <body>
                <table border="1" align="center">
                    <tr>
                        <th>1.经历站点个数</th>
                        <th>2.地铁站名</th>

                    </tr>
                    <%
                        //计算输入的起点与终点之间的站点数与换乘的最短路径
                        String station_name=request.getParameter("station_name");
                        String stop_station=request.getParameter("stop_station");
                        Connection connection = util.getConnection();
                        PreparedStatement preparedStatement = null;
                        ResultSet rs = null;
                        try{
                            String sql="WITH RECURSIVE transfer (start_station, stop_station, stops, path) AS (\r\n"
                                    + "  SELECT station_name, next_station, 1, CAST(CONCAT(line_name,station_name , '->', line_name,next_station) AS CHAR(1000))\r\n"
                                    + "    FROM bj_subway WHERE station_name = ?\r\n"
                                    + "   UNION ALL\r\n"
                                    + "  SELECT p.start_station, e.next_station, stops + 1, CONCAT(p.path, '->', e.line_name, e.next_station)\r\n"
                                    + "    FROM transfer p\r\n"
                                    + "    JOIN bj_subway e\r\n"
                                    + "      ON p.stop_station = e.station_name AND (INSTR(p.path, e.next_station) = 0)\r\n"
                                    + ")\r\n"
                                    + "SELECT * FROM transfer WHERE stop_station =? limit 2 ";

                            preparedStatement = connection.prepareStatement(sql);
                            preparedStatement.setString(1 ,station_name);
                            preparedStatement.setString(2 ,stop_station);
                            rs = preparedStatement.executeQuery();
                            while(rs.next()){
                    %>
                    <tr>
                    <td><%=rs.getString("stops") %></td>
                    <td><%=rs.getString("path") %></td>
                    </tr>
                    <%
                            }
                        }catch (Exception ex){
                            ex.printStackTrace();

                        }
                        finally{
                            util.close(rs,preparedStatement,connection);
                        }
                    %>

                </table>
            </body>
</html>

　　

posted @ 2023-03-23 22:09  南北啊  阅读(14)  评论(0)    收藏  举报
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