每日短讯：开学小测总结（下）

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每日短讯：开学小测总结（下）

2023-02-13 19:51:56 来源：博客园

【资料图】

接下来就是servlet的一些操作。

Dao.java

package sev;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import java.util.ArrayList;import java.util.List;import passage.XinWen;import tool.Tool;public class Dao {    public void add(XinWen xw) {        Connection conn=Tool.getConnection();        String sql="insert into xinwen (lanmu,timu,zhengwen) values (?,?,?) ";        try {            PreparedStatement ps = conn.prepareStatement(sql);            ps.setString(1, xw.getLanmu());            ps.setString(2, xw.getTimu());            ps.setString(3, xw.getZhengwen());            ps.executeUpdate();        }catch(SQLException e){            e.printStackTrace();        }        finally {            Tool.release(conn, null, null);        }    }    public void Up(String lanmu,String timu,String zhengwen ) {//修改        Connection connn=null;        PreparedStatement preparedStatement=null;        try {            connn= Tool.getConnection();            String sql="update xinwen set zhengwen=? where lanmu=? and timu=?";            preparedStatement=connn.prepareStatement(sql);            preparedStatement.setString(1,zhengwen);            preparedStatement.setString(2,lanmu);            preparedStatement.setString(3,timu);            preparedStatement.executeUpdate();        }        catch(SQLException e) {            e.printStackTrace();        } finally {            Tool.release(connn,preparedStatement,null);        }    }    public List findall() {        List list=new ArrayList<>();        Connection connection=null;        PreparedStatement preparedStatement=null;        ResultSet resultSet=null;        try {            //调用Tool连接mysql数据库            connection= Tool.getConnection();            String sql="select * from xinwen";//查询语句            preparedStatement=connection.prepareStatement(sql);            resultSet = preparedStatement.executeQuery();            while (resultSet.next()){                //从resultSet拿出每个属性数据                String lanmu=resultSet.getString ("lanmu");            String timu=resultSet.getString("timu");            String zhengwen=resultSet.getString("zhengwen");                //这里可以理解为，resultSet拿出每个属性数据赋予student对象，形成一个有数据的student对象            XinWen t = new XinWen(lanmu,zhengwen,timu);                list.add(t);//可能多条数据，放到集合中            }        } catch (SQLException e) {            e.printStackTrace();        } finally {            //调用JDBCTools，关闭connection，preparedStatement，resultSet            Tool.release(connection,preparedStatement,resultSet);        }        return list;    }    public List findyj() {        List list=new ArrayList<>();        Connection connection=null;        PreparedStatement preparedStatement=null;        ResultSet resultSet=null;        try {            //调用Tool连接mysql数据库            connection= Tool.getConnection();            String sql="select * from xinwen";//查询语句            preparedStatement=connection.prepareStatement(sql);            resultSet = preparedStatement.executeQuery();            while (resultSet.next()){                //从resultSet拿出每个属性数据                String lanmu=resultSet.getString ("lanmu");            String timu=resultSet.getString("timu");            String zhengwen=resultSet.getString("yijian");                //这里可以理解为，resultSet拿出每个属性数据赋予student对象，形成一个有数据的student对象            String s=lanmu+"  "+timu+"  "+zhengwen;                list.add(s);//可能多条数据，放到集合中            }        } catch (SQLException e) {            e.printStackTrace();        } finally {            //调用JDBCTools，关闭connection，preparedStatement，resultSet            Tool.release(connection,preparedStatement,resultSet);        }        return list;    }    public XinWen finds(String timu,String lanmu) {//查询        Connection conn=Tool.getConnection();        PreparedStatement pre=null;        ResultSet res=null;        XinWen stu=null;        String sql="SELECT *FROM xinwen where timu=? and lanmu=?";        try {        pre=conn.prepareStatement(sql);        pre.setString(1, timu);        pre.setString(2, lanmu);        res=pre.executeQuery();        while(res.next()) {            String lanmu1=res.getString ("lanmu");            String timu1=res.getString("timu");            String zhengwen=res.getString("zhengwen");            stu=new XinWen(lanmu1,zhengwen,timu1);        }        }    catch(SQLException e) {                        e.printStackTrace();        }finally{            Tool.release(conn, pre, res);        }        return stu;    }    public void del(String timu) {//删除        Connection connn=null;        PreparedStatement preparedStatement=null;        try {            connn= Tool.getConnection();            String sql="delete from xinwen where timu=?";            preparedStatement=connn.prepareStatement(sql);            preparedStatement.setString(1,timu);            preparedStatement.executeUpdate();            } catch (SQLException e) {                e.printStackTrace();            }finally {                Tool.release(connn,preparedStatement,null);            }    }    public void adds(XinWen g) {        Connection conn=Tool.getConnection();        String sql="insert into yifabu (lanmu,timu,zhengwen) values (?,?,?) ";        try {            PreparedStatement ps = conn.prepareStatement(sql);            ps.setString(1, g.getLanmu());            ps.setString(2, g.getTimu());            ps.setString(3, g.getZhengwen());            ps.executeUpdate();        }catch(SQLException e){            e.printStackTrace();        }        finally {            Tool.release(conn, null, null);        }    }    public XinWen findm(String timu) {//查询        Connection conn=Tool.getConnection();        XinWen stu=null;        ResultSet rs = null;         Statement stmt = null;          try {                          String sql = "SELECT *FROM xinwen where xinwen.timu like "%"+timu+"%";";  //查询语句            stmt = conn.createStatement();              rs = stmt.executeQuery(sql);          while(rs.next()) {            String lanmu1=rs.getString ("lanmu");            String timu1=rs.getString("timu");            String zhengwen=rs.getString("zhengwen");            stu=new XinWen(lanmu1,zhengwen,timu1);        }        }    catch(SQLException e) {                        e.printStackTrace();        }finally{            Tool.release(conn, stmt, rs);        }        return stu;    }}

sev.java

package sev;import java.io.IOException;import java.util.List;import passage.XinWen;import jakarta.servlet.ServletException;import jakarta.servlet.annotation.WebServlet;import jakarta.servlet.http.HttpServlet;import jakarta.servlet.http.HttpServletRequest;import jakarta.servlet.http.HttpServletResponse;@WebServlet("/xw")public class Sev extends HttpServlet{Dao d=new Dao();public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{    String method=request.getParameter("method");    switch(method) {    case "add":         String lanmu= request.getParameter("lanmu");         String zhengwen=request.getParameter("word");         String timu=request.getParameter("tm");         XinWen xw=new XinWen(lanmu,zhengwen,timu);         d.add(xw);         request.setAttribute("test", "公文上传成功");               request.getRequestDispatcher("tishi1.jsp").forward(request, response);        break;    case "findall"://查询所有数据    List list = d.findall();    request.setAttribute("test", list);    request.getRequestDispatcher("tmessage.jsp").forward(request, response);    break;    case "findalls"://查询所有数据        List listss = d.findall();        request.setAttribute("test", listss);        request.getRequestDispatcher("tme.jsp").forward(request, response);        break;    case "findAll"://查询所有数据        List lists = d.findall();        request.setAttribute("test", lists);        request.getRequestDispatcher("all.jsp").forward(request, response);        break;    case "findyj":        List list1 = d.findyj();        request.setAttribute("test", list1);        request.getRequestDispatcher("yijian.jsp").forward(request, response);        break;    case "findById":        String lanmu1=request.getParameter("lanmu");        String timu1=request.getParameter("timu");        XinWen st=d.finds(timu1,lanmu1);        request.setAttribute("test", st);        request.getRequestDispatcher("update.jsp").forward(request, response);        break;    case "up":        String l= request.getParameter("lanmu");           String t=request.getParameter("timu");           String z=request.getParameter("zhengwen");        d.Up(l,t,z);        request.setAttribute("test", "修改成功");        request.getRequestDispatcher("tishi1.jsp").forward(request, response);     case "delete"://删除操作         String timus=request.getParameter("timu");         d.del(timus);         request.setAttribute("test", "删除成功");         request.getRequestDispatcher("tishi1.jsp").forward(request, response);         break;     case "fabu":         String ll= request.getParameter("lanmu");               String tt=request.getParameter("timu");               String zz=request.getParameter("zhengwen");               XinWen xx=new XinWen(ll,zz,tt);               d.adds(xx);               request.setAttribute("test", "发布成功");             request.getRequestDispatcher("tishi1.jsp").forward(request, response);         break;     case "findm":         String timue= request.getParameter("tm");         XinWen xxx=d.findm(timue);         request.setAttribute("test", xxx);             request.getRequestDispatcher("tishi1.jsp").forward(request, response);         break;    }}@Overridepublic void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{    doPost(request,response);}}

Daof.java

package sev;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.util.ArrayList;import java.util.List;import passage.XinWen;import tool.Tool;public class Daof {    public List findall() {        List list=new ArrayList<>();        Connection connection=null;        PreparedStatement preparedStatement=null;        ResultSet resultSet=null;        try {            //调用Tool连接mysql数据库            connection= Tool.getConnection();            String sql="select * from yifabu";//查询语句            preparedStatement=connection.prepareStatement(sql);            resultSet = preparedStatement.executeQuery();            while (resultSet.next()){                //从resultSet拿出每个属性数据                String lanmu=resultSet.getString ("lanmu");            String timu=resultSet.getString("timu");            String zhengwen=resultSet.getString("zhengwen");                //这里可以理解为，resultSet拿出每个属性数据赋予student对象，形成一个有数据的student对象            XinWen t = new XinWen(lanmu,zhengwen,timu);                list.add(t);//可能多条数据，放到集合中            }        } catch (SQLException e) {            e.printStackTrace();        } finally {            //调用JDBCTools，关闭connection，preparedStatement，resultSet            Tool.release(connection,preparedStatement,resultSet);        }        return list;    }    public String cp(String lanmu,String timu) {        Connection conn=Tool.getConnection();        PreparedStatement pre=null;        ResultSet res=null;        String stu=null;        String sql="SELECT *FROM yifabu where lanmu=? and timu=? ";        try {        pre=conn.prepareStatement(sql);        pre.setString(1, lanmu);        pre.setString(2, timu);        res=pre.executeQuery();        while(res.next()) {            String pl=res.getString("pinglun");            stu=pl;        }        }    catch(SQLException e) {                        e.printStackTrace();        }finally{            Tool.release(conn, pre, res);        }        return stu;    }    public void Up(String lanmu,String timu,String pinglun) {//修改        Connection connn=null;        PreparedStatement preparedStatement=null;        try {            connn=Tool.getConnection();            connn= Tool.getConnection();            String sql="update yifabu set pinglun=? where lanmu=? and timu=?";            preparedStatement=connn.prepareStatement(sql);            preparedStatement.setString(1,pinglun);            preparedStatement.setString(2,lanmu);            preparedStatement.setString(3,timu);            preparedStatement.executeUpdate();        }        catch(SQLException e) {            e.printStackTrace();        } finally {            Tool.release(connn,preparedStatement,null);        }    }}

Sevf.java

package sev;import java.io.IOException;import java.util.List;import passage.XinWen;import jakarta.servlet.ServletException;import jakarta.servlet.annotation.WebServlet;import jakarta.servlet.http.HttpServlet;import jakarta.servlet.http.HttpServletRequest;import jakarta.servlet.http.HttpServletResponse;@WebServlet("/xwf")public class Sevf extends HttpServlet{Daof d=new Daof();public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{    String method=request.getParameter("method");    switch(method) {    case "findAll"://查询所有数据        List lists = d.findall();        request.setAttribute("test", lists);        request.getRequestDispatcher("alls.jsp").forward(request, response);        break;    case "cp":        String lanmu=request.getParameter("lanmu");        String timu=request.getParameter("timu");        String pinglun=d.cp(lanmu, timu);        request.setAttribute("test", pinglun);        request.getRequestDispatcher("pinglun.jsp").forward(request, response);        break;    case "fa":        String lanmus=request.getParameter("lanmu");        String timus=request.getParameter("timu");        request.setAttribute("test", lanmus);        request.setAttribute("tests", timus);        request.getRequestDispatcher("fabiaopl.jsp").forward(request, response);        break;    case "fas":        String lanmuss=request.getParameter("lanmu");        String timuss=request.getParameter("timu");        String pl=request.getParameter("pl");        d.Up(lanmuss, timuss, pl);        break;    }}@Overridepublic void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{    doPost(request,response);}}

总结本次的开学测试，有许多的功能没有实现，总分40分，得了24分，一些细节的功能没有完成，之后的两个权限没有完成，一些用户的信息管理。之前的那个修改意见不可以提出。

关键词：属性数据查询语句形成一个