地铁售票系统设计思想及部分代码

     设计思想：地铁售票系统的关键点在于换乘，所以首先要分为换乘和不换乘两种情况。不换乘比较简单，通过起始站名和终点站名查询他们的num，然后list打包输出到jsp就可以。换乘的话就先要找到两条线路，找到两条线路的交点也就是换乘站，然后分别输出起始站到换乘站，换乘站到终点站两段路线就完成了，这里面还涉及到一个最短路径问题，我的想法是把全部的可能线路都找到，然后比较大小就完成了。目前进度到换乘部分。

     双人项目合作人：郑锦

     部分源代码：

package Dao;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;

import connection.DBUtil;


public class dao {

	
	/**
	 * 通过name得到number(线路号)
	 * @param name
	 * @return
	 */
	public static int getNum(String name) {
		String sql = "select xianluhao from aaa where name ='" + name + "'";
		Connection conn = DBUtil.getConn();
		Statement state = null;
		ResultSet rs = null;
		int number=0;
		
		try {
			state = conn.createStatement();
			rs = state.executeQuery(sql);
			while (rs.next()) {
				
				
				number = rs.getInt("xianluhao");
			
				
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			DBUtil.close(rs, state, conn);
		}
		
		return number;
	}
	/**
	 * 通过name得到zhanhao(站台号)
	 * @param name
	 * @return
	 */
	public static int getZhanhao(String name) {
		String sql = "select num from aaa where name ='" + name + "'";
		Connection conn = DBUtil.getConn();
		Statement state = null;
		ResultSet rs = null;
		int zhanhao=0;
		
		try {
			state = conn.createStatement();
			rs = state.executeQuery(sql);
			while (rs.next()) {
				
				
				zhanhao = rs.getInt("num");
			
				
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			DBUtil.close(rs, state, conn);
		}
		
		return zhanhao;
	}
	
	

	public static String getLine1(int zhanhao1,int zhanhao2) {
		
		String line="";
		String sql = "select name from aaa where num between '"+zhanhao1+"' and '"+zhanhao2+"'order by num ASC ";//升序
				
		Connection conn = DBUtil.getConn();
		Statement state = null;
		ResultSet rs = null;	
		try {
			state = conn.createStatement();
			rs = state.executeQuery(sql);
			
			if(rs.next())
				line=rs.getString("name");
			while (rs.next()) {
				String name=rs.getString("name");
				line=line+"->"+name;
			
				}
			
	     } catch (Exception e) {
		e.printStackTrace();
	     } finally {
		DBUtil.close(rs, state, conn);
	    }
	
		
		return line;
	}
	
public static String getLine2(int zhanhao1,int zhanhao2) {
		
		String line="";
		String sql = "select name from aaa where num between '"+zhanhao1+"' and '"+zhanhao2+"'  order by num DESC ";//降序
				
		Connection conn = DBUtil.getConn();
		Statement state = null;
		ResultSet rs = null;	
		try {
			state = conn.createStatement();
			rs = state.executeQuery(sql);
			
			if(rs.next())
				line=rs.getString("name");
			while (rs.next()) {
				String name=rs.getString("name");
				line=line+"->"+name;
			
				}
			
	     } catch (Exception e) {
		e.printStackTrace();
	     } finally {
		DBUtil.close(rs, state, conn);
	    }
	
		
		return line;
	}}

　　

package servlet;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import Dao.dao;

@WebServlet("/servlet")
public class servlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

	
	protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		req.setCharacterEncoding("utf-8");
		String method = req.getParameter("method");
		if ("chaxun".equals(method)) {
			chaxun(req, resp);
			} 
	}
	private void chaxun(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		// TODO Auto-generated method stub
		req.setCharacterEncoding("utf-8");
		
		 String qi=req.getParameter("qi");
		 String zhong=req.getParameter("zhong");
		 int zhanhao1=dao.getZhanhao(qi);
		 int zhanhao2=dao.getZhanhao(zhong);
		 int number1=dao.getNum(qi);
		 int number2=dao.getNum(zhong);
	     if(number1==number2) {
			if(zhanhao1<zhanhao2)
			{
			String line=dao.getLine1(zhanhao1, zhanhao2);
			req.setAttribute("line",line );
			req.setAttribute("num",number1);
			req.getRequestDispatcher("list.jsp").forward(req,resp);
			
			}if(zhanhao1>zhanhao2)
			{
			String line=dao.getLine2(zhanhao2, zhanhao1);
			System.out.print(line);
			req.setAttribute("num",number1);
			req.setAttribute("line",line );
			req.getRequestDispatcher("list.jsp").forward(req,resp);
			}
}}}

　　实验截图

项目总结分析

这个项目因为涉及到一个最短路径的问题，最开始我是想用迪杰斯特拉算法来解决这个问题。但是我尝试了很久没有成功，可能是我的水平还是太有限。所以最后用了最简单的方法来解决这个问题。我了解到有的同学是用迪杰斯特拉算法完成了这个项目，所以还是去请教一下。后期有时间的话还是想改善一下我程序的算法。