使用servlet 查询数据库后记录显示在jsp页面，有没有大佬救一下，急！

Question

 model层：

package com.pxb.model;

public class Guard {
    private Integer guardId;
    private String username;
    private String password;
    private String guardName;
    private String sex;
    private String tel;
    private String buildingName;

    @Override
    public String toString() {
        return "Guard{" +
                "guardId=" + guardId +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                ", guardName='" + guardName + '\'' +
                ", sex='" + sex + '\'' +
                ", tel='" + tel + '\'' +
                ", buildingName='" + buildingName + '\'' +
                '}';
    }

    public String getBuildingName() {
        return buildingName;
    }

    public void setBuildingName(String buildingName) {
        this.buildingName = buildingName;
    }

    public Guard(String username, String password) {
        this.username = username;
        this.password = password;
    }

    public Integer getGuardId() {
        return guardId;
    }

    public void setGuardId(Integer guardId) {
        this.guardId = guardId;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getGuardName() {
        return guardName;
    }

    public void setGuardName(String guardName) {
        this.guardName = guardName;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public String getTel() {
        return tel;
    }

    public void setTel(String tel) {
        this.tel = tel;
    }

    public Guard() {
    }
}

 util层：

package com.pxb.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DbUtil {
    private static final String username = "root";
    private static final String password = "";
    private static final String driver = "com.mysql.jdbc.Driver";
    private static final String url = "jdbc:mysql://localhost:3306/db_housing?useUnicode=true&characterEncoding=UTF8";
    private Connection conn;

    static {
        try {
            Class.forName(driver);
            System.out.println("数据库加载驱动成功！");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
            System.out.println("数据库驱动加载异常！");
        }
    }

    public Connection getConnection(){
        try {
            conn = DriverManager.getConnection(url,username,password);
            System.out.println("数据库连接成功！");
        } catch (SQLException e) {
            e.printStackTrace();
            System.out.println("数据库连接失败！");
        }
        return conn;
    }

    public static void main(String[] args) {
        DbUtil d = new DbUtil();
        System.out.println(d.getConnection());
    }
}

 dao层：

package com.pxb.dao;


import com.pxb.model.Guard;
import com.pxb.util.DbUtil;
import com.pxb.util.StringUtil;

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 GuardDao {
    public List<Guard> guardList(Connection conn) throws SQLException {
        List<Guard> guardList = new ArrayList<Guard>();
        StringBuffer sb = new StringBuffer("select * from guard t1");
        PreparedStatement pstmt = conn.prepareStatement(sb.toString().replaceFirst("and","where"));
        ResultSet rs = pstmt.executeQuery();
        while(rs.next()){
            Guard guard1 = new Guard();
            guard1.setGuardId(rs.getInt("guardId"));
            guard1.setUsername(rs.getString("username"));
            guard1.setPassword(rs.getString("password"));
            guard1.setGuardName(rs.getString("guardName"));
            guard1.setBuildingName(rs.getString("buildingName"));
            guard1.setSex(rs.getString("sex"));
            guard1.setTel(rs.getString("tel"));
            guardList.add(guard1);
        }
        return guardList;
    }
    public static void main(String[] args) {
        GuardDao guardDao=new GuardDao();
        Connection con=null;
        DbUtil dbUtil=new DbUtil();
        con=dbUtil.getConnection();
        try {
            List<Guard> list=guardDao.guardList(con);
            System.out.println(list.toString());


        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }
    }
}

 servlet层：

package com.pxb.servlet;

import com.pxb.dao.GuardDao;
import com.pxb.model.Guard;
import com.pxb.util.DbUtil;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;

public class GuardServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;


    DbUtil dbUtil = new DbUtil();
    GuardDao guardDao = new GuardDao();

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        this.doPost(request,response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");

        System.out.println("=>进入servlet");

        Guard guard = new Guard();

        Connection conn = null;
        conn = dbUtil.getConnection();
        try {
            List<Guard> guardList = guardDao.guardList(conn);
            System.out.println(guardList.toString());
            request.setAttribute("guardList",guardList);
            request.setAttribute("mainPage","admin/guard.jsp");
            request.getRequestDispatcher("mainAdmin.jsp").forward(request,response);
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }

    }


}

 jsp页面：

<table class="table table-hover text-center">
        <tr>
<%--            <th width="100" style="text-align:left; padding-left:20px;">编号</th>--%>
<%--            <th width="10%">用户名</th>--%>
<%--            <th width="50">姓名</th>--%>
            <th>编号</th>
            <th>用户名</th>
            <th>姓名</th>
            <th>性别</th>
            <th>楼层</th>
            <th>电话</th>
<%--            <th width="10%">录入时间</th>--%>
            <th width="310">操作</th>
        </tr>
        <volist name="list" id="vo">
            <c:forEach varStatus="i" var="guard" items="${guardList}">
            <tr>
<%--                <td style="text-align:left; padding-left:20px;"><input type="checkbox" name="id[]" value="" />--%>
<%--                    1</td>--%>
                <td>${guard.guardId}</td>
                <td>${guard.username}</td>
                <td>${guard.guardName}</td>
                <td>${guard.sex}</td>
                <td>${guard.buildingName}</td>
                <td>${guard.tel}</td>
<%--                <td>2016-07-01</td>--%>
                <td><div class="button-group"> <a class="button border-main" href="add.html"><span class="icon-edit"></span> 修改</a> <a class="button border-red" href="javascript:void(0)" onclick="return del(1,1,1)"><span class="icon-trash-o"></span> 删除</a> </div></td>
            </tr>
            </c:forEach>
<%--            <tr>--%>
<%--                <td style="text-align:left; padding:19px 0;padding-left:20px;"><input type="checkbox" id="checkall"/>--%>
<%--                    全选 </td>--%>
<%--                <td colspan="7" style="text-align:left;padding-left:20px;"><a href="javascript:void(0)" class="button border-red icon-trash-o" style="padding:5px 15px;" onclick="DelSelect()"> 删除</a> </td>--%>
<%--            </tr>--%>
        </volist>
    </table>

Answer 1

这里可以远程协助 你可以提供向日葵代码