标签：java name rs SQLException 2022 sql import
地铁查询系统的实现：
现在我只做了站点查询和线路查询两个功能，其他的一些功能并没有完善，两个站点的最短路径是我这两天不知道如何解决的点。
package com.Dao;
import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
public class service {
public static List<String> searchstop(int line_id) throws ClassNotFoundException,SQLException, IOException{
List<String> stop= new ArrayList<>();
Connection connection = mysql.getconn();
PreparedStatement pstmt = null;
ResultSet rs = null;
try {
String sql = "select stop_name from subway where line_id = ?";
pstmt = connection.prepareStatement(sql);
pstmt.setInt(1, line_id);
rs = pstmt.executeQuery();
while(rs.next()) {
String name = rs.getString(1);
stop.add(name);
}
}catch(SQLException e) {
e.printStackTrace();
}catch(Exception e) {
e.printStackTrace();
}finally {
mysql.close(rs, pstmt, connection);
}
return stop;
}
public static List<String> searchline(String stop_name) throws ClassNotFoundException,SQLException, IOException{
List<String> line= new ArrayList<>();
Connection connection = mysql.getconn();
PreparedStatement pstmt = null;
ResultSet rs = null;
try {
String sql = "select line_name from subway where stop_name = ?";
pstmt = connection.prepareStatement(sql);
pstmt.setString(1, stop_name);
rs = pstmt.executeQuery();
while(rs.next()) {
String name = rs.getString(1);
line.add(name);
}
}catch(SQLException e) {
e.printStackTrace();
}catch(Exception e) {
e.printStackTrace();
}finally {
mysql.close(rs, pstmt, connection);
}
return line;
}
}
package com.Dao;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class mysql {
public static String url="jdbc:mysql://localhost:3306/subway";
public static String user="root";
public static String pass="yang";
public static Connection getconn() {
Connection conn=null;
try {
Class.forName("com.mysql.cj.jdbc.Driver");
conn = DriverManager.getConnection(url,user,pass);
} catch (Exception e) {
e.printStackTrace();
}
return conn;
}
public static void close (PreparedStatement state, Connection conn) {
if (state != null) {
try {
state.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
public static void close (ResultSet rs, PreparedStatement state,Connection conn) throws IOException, SQLException{
if (rs != null) {
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (state != null) {
try {
state.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (conn != null) {
conn.close();
}
}
}
ackage com.Servlet;
import java.io.IOException;
import java.sql.SQLException;
import java.util.ArrayList;
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.Dao.service;
/**
* Servlet implementation class selectLine
*/
@WebServlet("/selectLine")
public class selectLine extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
String line_id = request.getParameter("line_id");
response.setContentType("text/html;charset=UTF-8");
List<String> list = new ArrayList<>();
try {
list = service.searchstop(Integer.parseInt(line_id));
String a = null;
for(int i=0;i<list.size();i++)
{
a = list.get(i);
response.getWriter().println(a + " ");
}
} catch (NumberFormatException | IOException | SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
package com.Servlet;
import java.io.IOException;
import java.sql.SQLException;
import java.util.ArrayList;
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.Dao.service;
/**
* Servlet implementation class selectStop
*/
@WebServlet("/selectStop")
public class selectStop extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
String stop_name = request.getParameter("stop_name");
response.setContentType("text/html;charset=UTF-8");
List<String> list = new ArrayList<>();
try {
list = service.searchline(stop_name);
String a = null;
for(int i=0;i<list.size();i++)
{
a = list.get(i);
response.getWriter().println(a + " ");
}
} catch (NumberFormatException | IOException | SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
标签：java,name,rs,SQLException,2022,sql,import 来源： https://www.cnblogs.com/yx111/p/16088828.html
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