時間	30小時
代碼量	2000行左右
博客園	2
知識點	知識點：從最基本的jsp連接數據庫學習。? ? ? ? ? List<類名> list=new ArrayList<>()：這就像是一個容器。能把數據儲存在 list里。 ResultSet rs：創建rs結果集可以用來接受儲存數據。 rs = state.executeQuery(sql)：就上面的代碼而言，excuteQuery就是對數據庫進行操作，然后再把值傳給rs結果集中。 rs.getString（“id”）：單獨提取id這個值。 基本熟悉select語句。select site from all_line where id between 1 and 6；? 搜索出id為1-6的站臺。 req.getParameter("line")：getParameter就是從網頁中獲取輸入的數據。 --------------------------------------------------------------------------------------------------------------------------------------------------------------------- String line=dao.line(site); req.setAttribute("lines", line);? ? ?將字符串line的數據導入到網頁lines中，設置lines提供為網頁的接收 <td><%=request.getAttribute("lines") %></td>? ?網頁接受lines的數據。

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package com.sub.dao; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.ArrayList; import java.util.List;import com.sub.been.SubwayBeen; import com.sub.util.DBUtil; public class SubwayDao {/** 搜索一號線的所有路線*/public List<SubwayBeen> one_line(String line, String intro, String route,String site) {String sql = "select * from one_line order by id ASC";List<SubwayBeen> list = new ArrayList<>();Connection conn = DBUtil.getConn();Statement state = null;ResultSet rs = null;try {state = conn.createStatement();rs = state.executeQuery(sql);SubwayBeen bean = null;while (rs.next()) {String id = rs.getString("id");String line2 = rs.getString("line");String intro2 = rs.getString("intro");String route2 = rs.getString("route");String site2 = rs.getString("site");bean = new SubwayBeen(id, line2, intro2, route2,site2);list.add(bean);}} catch (SQLException e) {e.printStackTrace();} finally {DBUtil.close(rs, state, conn);}return list;}/** 搜索二號線的所有路線*/public List<SubwayBeen> two_line(String line, String intro, String route,String site) {String sql = "select * from two_line order by id ASC";List<SubwayBeen> list = new ArrayList<>();Connection conn = DBUtil.getConn();Statement state = null;ResultSet rs = null;try {state = conn.createStatement();rs = state.executeQuery(sql);SubwayBeen bean = null;while (rs.next()) {String id = rs.getString("id");String line2 = rs.getString("line");String intro2 = rs.getString("intro");String route2 = rs.getString("route");String site2 = rs.getString("site");bean = new SubwayBeen(id, line2, intro2, route2,site2);list.add(bean);}} catch (SQLException e) {e.printStackTrace();} finally {DBUtil.close(rs, state, conn);}return list;}/** 搜索四號線的所有路線*/public List<SubwayBeen> four_line(String line, String intro, String route,String site) {String sql = "select * from four_line order by id ASC";List<SubwayBeen> list = new ArrayList<>();Connection conn = DBUtil.getConn();Statement state = null;ResultSet rs = null;try {state = conn.createStatement();rs = state.executeQuery(sql);SubwayBeen bean = null;while (rs.next()) {String id = rs.getString("id");String line2 = rs.getString("line");String intro2 = rs.getString("intro");String route2 = rs.getString("route");String site2 = rs.getString("site");bean = new SubwayBeen(id, line2, intro2, route2,site2);list.add(bean);}} catch (SQLException e) {e.printStackTrace();} finally {DBUtil.close(rs, state, conn);}return list;}/** 搜索四號線支線的所有路線*/public List<SubwayBeen> four_feederline(String line, String intro, String route,String site) {String sql = "select * from four_feederline order by id ASC";List<SubwayBeen> list = new ArrayList<>();Connection conn = DBUtil.getConn();Statement state = null;ResultSet rs = null;try {state = conn.createStatement();rs = state.executeQuery(sql);SubwayBeen bean = null;while (rs.next()) {String id = rs.getString("id");String line2 = rs.getString("line");String intro2 = rs.getString("intro");String route2 = rs.getString("route");String site2 = rs.getString("site");bean = new SubwayBeen(id, line2, intro2, route2,site2);list.add(bean);}} catch (SQLException e) {e.printStackTrace();} finally {DBUtil.close(rs, state, conn);}return list;}/** 根據站臺名獲取該站臺的id*/public String id(String site){String sql="select id from all_line where site = '"+site+"'";Connection conn = DBUtil.getConn();Statement state = null;String id=null;ResultSet rs = null;try{state=conn.createStatement();rs = state.executeQuery(sql);while(rs.next()){id=rs.getString("id");}}catch (SQLException e) {e.printStackTrace();} finally {DBUtil.close(rs, state, conn);}return id;}/** 根據站臺名獲取該站臺屬于幾號線路*/public String line(String site){String sql="select line from all_line where site = '"+site+"'";Connection conn = DBUtil.getConn();Statement state = null;String line=null;ResultSet rs = null;try{state=conn.createStatement();rs = state.executeQuery(sql);while(rs.next()){line=rs.getString("line");}}catch (SQLException e) {e.printStackTrace();} finally {DBUtil.close(rs, state, conn);}return line;}/** 根據獲取的id值搜索出其中間的站臺升序*/public String station1(int id1,int id2){String sql="select site from all_line where id between '"+id1+"' and '"+id2+"' order by id ASC" ;Connection conn = DBUtil.getConn();Statement state = null;ResultSet rs = null;String route = "";try{state=conn.createStatement();rs = state.executeQuery(sql);if(rs.next())route=rs.getString("site");while(rs.next()){String site=rs.getString("site");route+="->"+site;}}catch (SQLException e) {e.printStackTrace();} finally {DBUtil.close(rs, state, conn);}return route;}/** 根據獲取的id值搜索出其中間的站臺降序*/public String station2(int id1,int id2){String sql="select site from all_line where id between '"+id1+"' and '"+id2+"' order by id DESC" ;Connection conn = DBUtil.getConn();Statement state = null;ResultSet rs = null;String route = "";try{state=conn.createStatement();rs = state.executeQuery(sql);if(rs.next())route=rs.getString("site");while(rs.next()){String site=rs.getString("site");route+="->"+site;}}catch (SQLException e) {e.printStackTrace();} finally {DBUtil.close(rs, state, conn);}return route;}} package com.sub.servlet;import java.io.IOException; import java.util.List;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 com.sub.been.SubwayBeen; import com.sub.dao.SubwayDao;@WebServlet("/SubwayServlet") public class SubwayServlet extends HttpServlet {private static final long serialVersionUID = 1L;SubwayDao dao=new SubwayDao();protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException{req.setCharacterEncoding("utf-8");String method = req.getParameter("method");if ("one_line".equals(method)) {one_line(req, resp);}else if("two_line".equals(method)) {two_line(req, resp);}else if("four_line".equals(method)) {four_line(req, resp);}else if("four_feederline".equals(method)) {four_feederline(req, resp);}else if("no_transfer1".equals(method)) {no_transfer1(req, resp);}else if("transfer".equals(method)) {transfer(req, resp);}}/** 搜索一號線的所有路線*/private void one_line(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{req.setCharacterEncoding("utf-8");String line = req.getParameter("line");String intro = req.getParameter("intro");String route = req.getParameter("route");String site = req.getParameter("site");List<SubwayBeen> ones = dao.one_line(line, intro, route,site);req.setAttribute("ones", ones);req.getRequestDispatcher("one_line_searchlist.jsp").forward(req,resp);}/** 搜索二號線的所有路線*/private void two_line(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{req.setCharacterEncoding("utf-8");String line = req.getParameter("line");String intro = req.getParameter("intro");String route = req.getParameter("route");String site = req.getParameter("site");List<SubwayBeen> twos = dao.two_line(line, intro, route,site);req.setAttribute("twos", twos);req.getRequestDispatcher("two_line_searchlist.jsp").forward(req,resp);}/** 搜索四號線的所有路線*/private void four_line(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{req.setCharacterEncoding("utf-8");String line = req.getParameter("line");String intro = req.getParameter("intro");String route = req.getParameter("route");String site = req.getParameter("site");List<SubwayBeen> fours = dao.four_line(line, intro, route,site);req.setAttribute("fours", fours);req.getRequestDispatcher("four_line_searchlist.jsp").forward(req,resp);}/** 搜索四號線支線的所有路線*/private void four_feederline(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{req.setCharacterEncoding("utf-8");String line = req.getParameter("line");String intro = req.getParameter("intro");String route = req.getParameter("route");String site = req.getParameter("site");List<SubwayBeen> four_feeders = dao.four_feederline(line, intro, route,site);req.setAttribute("four_feeders", four_feeders);req.getRequestDispatcher("four_feederline_searchlist.jsp").forward(req,resp);}/** 根據站臺名查詢出其中間站臺*/private void no_transfer1(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{req.setCharacterEncoding("utf-8");String site = req.getParameter("site"); //從網頁獲取輸入的起始站臺int id1 = Integer.parseInt(dao.id(site)); //獲取其站臺id 將其轉換為int類型 String site2 = req.getParameter("site2"); //從網頁獲取輸入的終止站臺int id2 = Integer.parseInt(dao.id(site2)); //獲取其站臺id 將其轉換為int類型if(id1<id2){ String station=dao.station1(id1, id2); //dao層升序車站req.setAttribute("stations", station);String line=dao.line(site); //通過站名知道哪條線 System.out.print(line);req.setAttribute("lines", line);req.getRequestDispatcher("no_transfer_searchlist.jsp").forward(req,resp);//升序車站req.getRequestDispatcher("no_transfer_searchlist.jsp").forward(req,resp);//升序車站}else{String station=dao.station2(id2, id1);req.setAttribute("stations", station);String line=dao.line(site);req.setAttribute("lines", line);req.getRequestDispatcher("no_transfer_searchlist.jsp").forward(req,resp);//降序車站req.getRequestDispatcher("no_transfer_searchlist.jsp").forward(req,resp);//升序車站 }}private void transfer(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{req.setCharacterEncoding("utf-8");String site1 = req.getParameter("site1"); //獲取車站名int line1 = Integer.parseInt(dao.line(site1)); //將車站名獲取的線路轉換為整型int id1=Integer.parseInt(dao.id(site1)); //將車站名獲取的id轉換為整型 String site2 = req.getParameter("site2");int line2 = Integer.parseInt(dao.line(site2));int id2=Integer.parseInt(dao.id(site2)); //--------------------------------------1到2-----------------------------------if(line1==1&&line2==2){if(id1<=10){String station1=dao.station1(id1, 10); //升序req.setAttribute("stations1", station1);req.setAttribute("line1", line1);if(id2<=115){String station2=dao.station2(id2,115); //降序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}else{String station2=dao.station1(115,id2); //升序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}req.getRequestDispatcher("transfer_searchlist.jsp").forward(req,resp);}if(id1>10){String station1=dao.station2(10,id1); //降序req.setAttribute("stations1", station1);req.setAttribute("line1", line1);if(id2<=115){String station2=dao.station2(id2,115); //降序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}else{String station2=dao.station1(115,id2); //升序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}req.getRequestDispatcher("transfer_searchlist.jsp").forward(req,resp);}} //--------------------------------------2到1---------------------------------------if(line1==2&&line2==1){if(id1<=115){String station1=dao.station1(id1, 115); //升序req.setAttribute("stations1", station1);req.setAttribute("line1", line1);if(id2<=10){String station2=dao.station2(id2,10); //降序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}else{String station2=dao.station1(10,id2); //升序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}req.getRequestDispatcher("transfer_searchlist.jsp").forward(req,resp);}if(id1>115){String station1=dao.station2(115,id1); //降序req.setAttribute("stations1", station1);req.setAttribute("line1", line1);if(id2<=10){String station2=dao.station2(id2,10); //降序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}else{String station2=dao.station1(10,id2); //升序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}req.getRequestDispatcher("transfer_searchlist.jsp").forward(req,resp);}} //--------------------------------------1到4--------------------------------------- if(line1==1&&line2==4){if(id1<=12){String station1=dao.station1(id1, 12); //升序req.setAttribute("stations1", station1);req.setAttribute("line1", line1);if(id2<=1011){String station2=dao.station2(id2,1011); //降序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}else{String station2=dao.station1(1011,id2); //升序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}req.getRequestDispatcher("transfer_searchlist.jsp").forward(req,resp);}else{String station1=dao.station2(12, id1); //降序req.setAttribute("stations1", station1);req.setAttribute("line1", line1);if(id2<=1011){String station2=dao.station2(id2,1011); //降序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}else{String station2=dao.station1(1011,id2); //升序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}req.getRequestDispatcher("transfer_searchlist.jsp").forward(req,resp);}} //--------------------------------------4到1--------------------------------------- if(line1==4&&line2==1){if(id1<=1011){String station1=dao.station1(id1, 1011); //升序req.setAttribute("stations1", station1);req.setAttribute("line1", line1);if(id2<=12){String station2=dao.station2(id2,12); //降序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}else{String station2=dao.station1(12,id2); //升序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}req.getRequestDispatcher("transfer_searchlist.jsp").forward(req,resp);}else{String station1=dao.station2(1011, id1); //降序req.setAttribute("stations1", station1);req.setAttribute("line1", line1);if(id2<=12){String station2=dao.station2(id2,12); //降序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}else{String station2=dao.station1(12,id2); //升序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}req.getRequestDispatcher("transfer_searchlist.jsp").forward(req,resp);}} //-----------------------------------------------2到4----------------------------------if(line1==2&&line2==4){if(id1<=112){String station1=dao.station1(id1, 112); //升序req.setAttribute("stations1", station1);req.setAttribute("line1", line1);if(id2<=1011){String station2=dao.station2(id2,1008); //降序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}else{String station2=dao.station1(1008,id2); //升序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}req.getRequestDispatcher("transfer_searchlist.jsp").forward(req,resp);}else{String station1=dao.station2(112, id1); //降序req.setAttribute("stations1", station1);req.setAttribute("line1", line1);if(id2<=1011){String station2=dao.station2(id2,1008); //降序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}else{String station2=dao.station1(1008,id2); //升序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}req.getRequestDispatcher("transfer_searchlist.jsp").forward(req,resp);} } //-----------------------------------------------4到2----------------------------------if(line1==4&&line2==2){if(id1<=1008){String station1=dao.station1(id1, 1008); //升序req.setAttribute("stations1", station1);req.setAttribute("line1", line1);if(id2<=112){String station2=dao.station2(id2,112); //降序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}else{String station2=dao.station1(112,id2); //升序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}req.getRequestDispatcher("transfer_searchlist.jsp").forward(req,resp);}else{String station1=dao.station2(1008, id1); //降序req.setAttribute("stations1", station1);req.setAttribute("line1", line1);if(id2<=112){String station2=dao.station2(id2,112); //降序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}else{String station2=dao.station1(112,id2); //升序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);}req.getRequestDispatcher("transfer_searchlist.jsp").forward(req,resp);} } //--------------------------------------------4到4支線----------------------------------------------------if(line1==4&&line2==41){if(id1<=1018){String station1=dao.station1(id1, 1018); //升序req.setAttribute("stations1", station1);req.setAttribute("line1", line1);String station2=dao.station1(10001,id2); //升序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);req.getRequestDispatcher("transfer_searchlist.jsp").forward(req,resp);}else{String station1=dao.station2(1018, id1); //降序req.setAttribute("stations1", station1);req.setAttribute("line1", line1);String station2=dao.station1(10001,id2); //升序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);req.getRequestDispatcher("transfer_searchlist.jsp").forward(req,resp);}} //--------------------------------------------4支線到4-------------------------------------------- if(line1==41&&line2==4){String station1=dao.station2(10001, id1);//降序req.setAttribute("stations1", station1);req.setAttribute("line1", line1);if(id2<=1018){String station2=dao.station2(id2, 1018);//降序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);req.getRequestDispatcher("transfer_searchlist.jsp").forward(req,resp);}else{String station2=dao.station1(1018, id2);//升序req.setAttribute("stations2", station2);req.setAttribute("line2", line2);req.getRequestDispatcher("transfer_searchlist.jsp").forward(req,resp);}} }}

?

知識點：從最基本的jsp連接數據庫學習。? ? ? ? ?

List<類名> list=new ArrayList<>()：這就像是一個容器。能把數據儲存在 list里。

ResultSet rs：創建rs結果集可以用來接受儲存數據。

rs = state.executeQuery(sql)：就上面的代碼而言，excuteQuery就是對數據庫進行操作，然后再把值傳給rs結果集中。

rs.getString（“id”）：單獨提取id這個值。

基本熟悉select語句。select site from all_line where id between 1 and 6；? 搜索出id為1-6的站臺。

req.getParameter("line")：getParameter就是從網頁中獲取輸入的數據。

---------------------------------------------------------------------------------------------------------------------------------------------------------------------

String line=dao.line(site);
req.setAttribute("lines", line);? ? ?將字符串line的數據導入到網頁lines中，設置lines提供為網頁的接收

<td><%=request.getAttribute("lines") %></td>? ?網頁接受lines的數據。

轉載于:https://www.cnblogs.com/birdmmxx/p/10652277.html

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