Servlet及Filter基础实验

1 实验类型

验证型，2学时，必选实验

2 实验目的

掌握前后端协作过程；理解前后端数据交换原理；

3 实验要求

验证参考代码；修改参考代码，实现自己的设计；将关键结果截图及源代码整理成实验报告

4 实验环境

Windows 7 64、Open JDK 23+、Tomcat 11+、Spring Tools 4(STS4)、Visual Studio Code(VS Code)、Microsoft Edge/Chrome/Firefox等浏览器、sqlite-jdbc-3.41.0.0.jar

5 实验步骤

创建工作目录：{盘符}:/{学号}/exp5_advanced

用JSP实现学生表的增、删、改、查操作，前端：用JSP页面编写操作界面，后端：用4层架构通过JDBC存储数据于Sqlite数据库

后端

后端4层架构如下：

graph LR classDef process fill:#E5F6FF,stroke:#73A6FF,stroke-width:2px; subgraph "表现层 (Action)" A(JSP页面):::process end subgraph "业务逻辑层 (Service)" B(StudentService):::process end subgraph "数据访问层 (DAO)" C(StudentDAO):::process end subgraph "实体层 (Domain)" D(Student):::process end A -->|调用业务方法| B B -->|调用数据访问方法| C C -->|操作实体| D classDef database fill:#FFEBEB,stroke:#E68994,stroke-width:2px; E[(学生表)]:::database C -->|CRUD 操作| E

创建Java Web工程StudentCRUD
将sqlite-jdbc-3.49.1.0.jar放入WEB-INF/lib目录

创建实体类：xust.demo.stu.domain.Student，参考代码如下：

xust.demo.stu.domain.Student类
package xust.demo.stu.domain;

/**
 * Class Student
 * 学生表
 * 
 * @author XUST
 * @version 1.0, 2023-04-20
 */
public class Student {

  /**
   * 学号
   */
  private String no;

  public String getNo() {
    return no;
  }

  public void setNo(String newValue) {
    no = newValue;
  }

  /**
   * 姓名
   */
  private String name;

  public String getName() {
    return name;
  }

  public void setName(String newValue) {
    name = newValue;
  }

  /**
   * 性别
   */
  private String gender;

  public String getGender() {
    return gender;
  }

  public void setGender(String newValue) {
    gender = newValue;
  }

  /**
   * 年龄
   */
  private Integer age;

  public Integer getAge() {
    return age;
  }

  public void setAge(Integer newValue) {
    age = newValue;
  }

  /**
   * 所在系
   */
  private String dept;

  public String getDept() {
    return dept;
  }

  public void setDept(String newValue) {
    dept = newValue;
  }

  @Override
  /**
   * 将对象序列化为JSON字符串
   */
  public String toString() {
    return "{" + "\"no\": " + "\"" + no + "\"" + ", " + "\"name\": " + "\"" + name + "\"" + ", " + "\"gender\": " + "\""
        + gender + "\"" + ", " + "\"age\": " + age + ", " + "\"dept\": " + "\"" + dept + "\"" + "}";
  }
}

创建数据库连接类：xust.demo.ConnectionUtil；数据库文件存放在：d:/stu.db，代码中自动创建，无须手动创建，参考代码如下：

xust.demo.ConnectionUtil类
package xust.demo;

import java.sql.*;

/**
 * 连接辅助类
 */
public class ConnectionUtil {
  /**
   * 创建连接
   * 
   * @return 连接对象
   */
  public static Connection getConnection() {
    Connection res = null;

    try {
      Class.forName("org.sqlite.JDBC");
      // 在数据库文件stu.db存放在D盘下
      res = DriverManager.getConnection("jdbc:sqlite:d:/stu.db");
    } catch (Exception e) {
      System.err.println(e.getClass().getName() + ": " + e.getMessage());
      System.exit(0);
    }

    return res;
  }

  /**
   * 关闭连接
   * 
   * @param connection 连接对象
   */
  public static void closeConnection(Connection connection) {
    if (connection != null) {
      try {
        connection.close();
      } catch (Exception e) {
        System.err.println(e.getClass().getName() + ": " + e.getMessage());
        System.exit(0);
      }
    }
  }

  /**
   * 关闭语句
   * 
   * @param pstmt 语句对象
   */
  public static void closePstmt(PreparedStatement pstmt) {
    if (pstmt != null) {
      try {
        pstmt.close();
      } catch (Exception e) {
        System.err.println(e.getClass().getName() + ": " + e.getMessage());
        System.exit(0);
      }
    }
  }

  /**
   * 关闭语句
   * 
   * @param pstmt 语句对象
   */
  public static void closeStmt(Statement stmt) {
    if (stmt != null) {
      try {
        stmt.close();
      } catch (Exception e) {
        System.err.println(e.getClass().getName() + ": " + e.getMessage());
        System.exit(0);
      }
    }
  }
}

创建结果类：xust.demo.Result，参考代码如下：

xust.demo.Result类
package xust.demo;

/**
 * 操作结果类
 */
public class Result {

  /**
   * 结果码，0为成功
   */
  public int code;

  /**
   * 结果信息
   */
  public String message;

  /**
   * 结果数据
   */
  public Object data;

  public Result() {

  }

  public Result(Boolean v) {
    code = v ? 0 : 1;
  }
}

创建数据访问接口：xust.demo.stu.dao.StudentDao和实现类：xust.demo.stu.dao.StudentDaoImpl，参考代码如下：

xust.demo.stu.dao.StudentDao接口
package xust.demo.stu.dao;

import xust.demo.Result;
import xust.demo.stu.domain.Student;

public interface StudentDao {
  /**
   * 初始化表
   * 
   * @return
   */
  Result init();

  /**
   * 增
   * 
   * @param o
   * @return
   */
  Result create(Student o);

  /**
   * 删
   * 
   * @param id
   * @return
   */
  Result delete(String no);

  /**
   * 改
   * 
   * @param o
   * @return
   */
  Result update(Student o);

  /**
   * 查
   * 
   * @param no
   * @return
   */
  Result get(String no);

  /**
   * 查
   * 
   * @return
   */
  Result getAll();
}

xust.demo.stu.dao.StudentDaoImpl类
package xust.demo.stu.dao;

import java.sql.*;
import java.util.ArrayList;
import xust.demo.Result;
import xust.demo.ConnectionUtil;
import xust.demo.stu.domain.Student;

public class StudentDaoImpl implements StudentDao {
  public Result init() {
    Result res = new Result(false);

    Connection con = null;
    Statement stmt = null;
    String sql = "create table Student(" +
        "no TEXT primary key," +
        "name TEXT not null," +
        "gender TEXT," +
        "age INTEGER," +
        "dept TEXT" +
        ");";

    con = ConnectionUtil.getConnection();
    if (con != null) {
      try {
        stmt = con.createStatement();
        ResultSet rs = stmt.executeQuery(String.format(
            "select count(*) from sqlite_master where type = 'table' and Upper(name) = '%s'", "Student".toUpperCase()));
        while (rs.next()) {
          int count = rs.getInt(1);

          if (count == 0 && stmt.executeUpdate(sql) > 0) {
            res.code = 0;
          }
        }
      } catch (Exception e) {
        e.printStackTrace();
        res.message = e.getMessage();
      } finally {
        ConnectionUtil.closeStmt(stmt);
        ConnectionUtil.closeConnection(con);
      }
    }

    return res;
  }

  /**
   * 对象填充到关系
   */
  private void toR(Student o, PreparedStatement stmt) throws Exception {
    if (o != null && stmt != null) {
      String no = o.getNo();
      if (no != null) {
        stmt.setString(1, no);
      }
      String name = o.getName();
      if (name != null) {
        stmt.setString(2, name);
      }
      String gender = o.getGender();
      if (gender != null) {
        stmt.setString(3, gender);
      }
      Integer age = o.getAge();
      if (age != null) {
        stmt.setInt(4, age);
      }
      String dept = o.getDept();
      if (dept != null) {
        stmt.setString(5, dept);
      }
    }
  }

  /**
   * 关系填充到对象
   */
  private Student toO(ResultSet rs) throws Exception {
    Student res = null;

    if (rs != null) {
      res = new Student();
      res.setNo(rs.getString("no"));
      res.setName(rs.getString("name"));
      res.setGender(rs.getString("gender"));
      res.setAge(rs.getInt("age"));
      res.setDept(rs.getString("dept"));
    }

    return res;
  }

  public Result create(Student o) {
    Result res = new Result(false);

    Connection con = null;
    PreparedStatement stmt = null;
    String sql = "insert into Student values (?, ?, ?, ?, ?)";
    con = ConnectionUtil.getConnection();
    if (o != null && con != null) {
      try {
        stmt = con.prepareStatement(sql);
        toR(o, stmt);
        int row_effected = stmt.executeUpdate();
        if (row_effected > 0) {
          res.code = 0;
        }
        res.data = row_effected;
      } catch (Exception e) {
        res.message = e.getMessage();
        e.printStackTrace();
      } finally {
        ConnectionUtil.closePstmt(stmt);
        ConnectionUtil.closeConnection(con);
      }
    }

    return res;
  }

  public Result delete(String no) {
    Result res = new Result(false);

    Connection con = null;
    PreparedStatement stmt = null;
    String sql = "delete from Student where no = ?;";
    con = ConnectionUtil.getConnection();
    if (con != null) {
      try {

        stmt = con.prepareStatement(sql);
        stmt.setString(1, no);
        int row_effected = stmt.executeUpdate();
        if (row_effected > 0) {
          res.code = 0;
        }
        res.data = row_effected;
      } catch (Exception e) {
        res.message = e.getMessage();
        e.printStackTrace();
      } finally {
        ConnectionUtil.closePstmt(stmt);
        ConnectionUtil.closeConnection(con);
      }
    }

    return res;
  }

  public Result update(Student o) {
    Result res = new Result(false);

    Connection con = null;
    PreparedStatement stmt = null;
    String sql = "update Student set No = ?, Name = ?, Gender = ?, Age = ?, Dept = ? where no = ?";
    con = ConnectionUtil.getConnection();
    if (o != null && con != null) {
      try {

        stmt = con.prepareStatement(sql);
        toR(o, stmt);
        stmt.setString(6, o.getNo());
        int row_effected = stmt.executeUpdate();
        if (row_effected > 0) {
          res.code = 0;
        }
        res.data = row_effected;
      } catch (Exception e) {
        e.printStackTrace();
        res.message = e.getMessage();
      } finally {
        ConnectionUtil.closePstmt(stmt);
        ConnectionUtil.closeConnection(con);
      }
    }

    return res;
  }

  public Result get(String no) {
    Result res = new Result(false);

    Connection con = null;
    PreparedStatement stmt = null;
    String sql = "select * from Student where no = ?";
    con = ConnectionUtil.getConnection();
    if (con != null) {
      try {
        stmt = con.prepareStatement(sql);
        stmt.setString(1, no);
        ResultSet rs = stmt.executeQuery();
        Student last = null;
        while (rs.next()) {
          last = new Student();
          last.setNo(rs.getString("no"));
          last.setName(rs.getString("name"));
          last.setGender(rs.getString("gender"));
          last.setAge(rs.getInt("age"));
          last.setDept(rs.getString("dept"));
        }

        res.code = 0;
        res.data = last;
      } catch (Exception e) {
        res.message = e.getMessage();
        e.printStackTrace();
      } finally {
        ConnectionUtil.closePstmt(stmt);
        ConnectionUtil.closeConnection(con);
      }
    }

    return res;
  }

  public Result getAll() {
    Result res = new Result(false);

    Connection con = null;
    PreparedStatement stmt = null;
    String sql = "select * from Student";
    con = ConnectionUtil.getConnection();
    if (con != null) {
      try {
        stmt = con.prepareStatement(sql);
        ResultSet rs = stmt.executeQuery();
        ArrayList<Student> data = new ArrayList<Student>();
        while (rs.next()) {
          Student last = toO(rs);
          data.add(last);
        }

        res.code = 0;
        res.data = data;
      } catch (Exception e) {
        res.message = e.getMessage();
        e.printStackTrace();
      } finally {
        ConnectionUtil.closePstmt(stmt);
        ConnectionUtil.closeConnection(con);
      }
    }

    return res;
  }
}

创建业务逻辑接口：xust.demo.stu.service.StudentService和实现类：xust.demo.stu.service.StudentServiceImpl，参考代码如下：

xust.demo.stu.serviceStudentService接口
package xust.demo.stu.service;

import xust.demo.Result;
import xust.demo.stu.domain.Student;
import jakarta.servlet.http.HttpServletRequest;

public interface StudentService {
  Student toO(HttpServletRequest request);

  /**
   * 增
   * 
   * @param o
   * @return
   */
  Result create(Student o);

  /**
   * 删
   * 
   * @param id
   * @return
   */
  Result delete(String no);

  /**
   * 改
   * 
   * @param o
   * @return
   */
  Result update(Student o);

  /**
   * 查
   * 
   * @param no
   * @return
   */
  Result get(String no);

  /**
   * 查
   * 
   * @return
   */
  Result getAll();
}

xust.demo.stu.service.StudentServiceImpl类
package xust.demo.stu.service;

import xust.demo.Result;
import xust.demo.stu.domain.Student;
import xust.demo.stu.dao.StudentDao;
import xust.demo.stu.dao.StudentDaoImpl;
import jakarta.servlet.http.HttpServletRequest;

public class StudentServiceImpl implements StudentService {
  private StudentDao _StudentDao;

  public StudentServiceImpl() {
    _StudentDao = new StudentDaoImpl();
    _StudentDao.init();
  }

  /**
   * 参数填充到对象
   */
  public Student toO(HttpServletRequest request) {
    Student res = null;

    if (request != null) {
      res = new Student();
      String p = null;
      p = request.getParameter("no");
      if (p != null) {
        res.setNo(request.getParameter("no"));
      }
      p = request.getParameter("name");
      if (p != null) {
        res.setName(request.getParameter("name"));
      }
      p = request.getParameter("gender");
      if (p != null) {
        res.setGender(request.getParameter("gender"));
      }
      p = request.getParameter("age");
      if (p != null) {
        res.setAge(Integer.parseInt(request.getParameter("age")));
      }
      p = request.getParameter("dept");
      if (p != null) {
        res.setDept(request.getParameter("dept"));
      }
    }

    return res;
  }

  public Result create(Student o) {
    Result res = new Result(false);

    if (_StudentDao != null && o != null) {
      res = _StudentDao.create(o);
    }

    return res;
  }

  public Result delete(String no) {
    Result res = new Result(false);

    if (_StudentDao != null) {
      res = _StudentDao.delete(no);
    }

    return res;
  }

  public Result update(Student o) {
    Result res = new Result(false);

    if (_StudentDao != null && o != null) {
      res = _StudentDao.update(o);
    }

    return res;
  }

  public Result get(String no) {
    Result res = new Result(false);

    if (_StudentDao != null) {
      res = _StudentDao.get(no);
    }

    return res;
  }

  public Result getAll() {
    Result res = new Result(false);

    if (_StudentDao != null) {
      res = _StudentDao.getAll();
    }

    return res;
  }
}

前端

前端主要页面功能如下：

url	功能
`/stu/init.jsp`	初始化学生列表，成功后跳转到`list.jsp`
`/stu/list.jsp`	以表格显示学生列表，每行包含修改、删除链接
`/stu/add_view.jsp`	添加学生页面，成功后跳转到`list.jsp`
`/stu/add.jsp`	添加学生，成功后跳转到`list.jsp`
`/stu/update_view.jsp`	修改学生页面，成功后跳转到`list.jsp`
`/stu/delete.jsp`	删除学生，成功后跳转到`list.jsp`
`/stu/update.jsp`	修改学生，成功后跳转到`list.jsp`

sequenceDiagram title JSP实现学生表增删改查操作流程（4层架构与SQLite） participant User participant InitJSP as /stu/init.jsp participant ListJSP as /stu/list.jsp participant AddViewJSP as /stu/add_view.jsp participant AddJSP as /stu/add.jsp participant UpdateViewJSP as /stu/update_view.jsp participant DeleteJSP as /stu/delete.jsp participant UpdateJSP as /stu/update.jsp participant Controller participant Service participant DAO participant SQLiteDB User->>InitJSP: 访问初始化页面 InitJSP->>Controller: 调用初始化逻辑 Controller->>Service: 调用服务层初始化方法 Service->>DAO: 调用数据访问层获取学生列表方法 DAO->>SQLiteDB: 执行SQL查询获取学生列表数据 SQLiteDB-->>DAO: 返回学生列表数据 DAO-->>Service: 返回学生列表数据 Service-->>Controller: 返回学生列表数据 Controller-->>ListJSP: 初始化成功，跳转并传递学生列表数据 User->>ListJSP: 查看学生列表 User->>ListJSP: 点击添加链接 ListJSP-->>AddViewJSP: 跳转到添加页面 User->>AddViewJSP: 填写学生信息并提交 AddViewJSP->>Controller: 传递添加学生信息 Controller->>Service: 调用服务层添加学生方法 Service->>DAO: 调用数据访问层添加学生方法 DAO->>SQLiteDB: 执行SQL插入操作添加学生数据 SQLiteDB-->>DAO: 返回操作结果 DAO-->>Service: 返回添加操作结果 Service-->>Controller: 返回添加操作结果 Controller-->>ListJSP: 添加成功，跳转 User->>ListJSP: 查看更新后的学生列表 User->>ListJSP: 点击某行修改链接 ListJSP-->>UpdateViewJSP: 跳转到修改页面并传递学生信息 User->>UpdateViewJSP: 修改学生信息并提交 UpdateViewJSP->>Controller: 传递修改后学生信息 Controller->>Service: 调用服务层修改学生方法 Service->>DAO: 调用数据访问层修改学生方法 DAO->>SQLiteDB: 执行SQL更新操作修改学生数据 SQLiteDB-->>DAO: 返回操作结果 DAO-->>Service: 返回修改操作结果 Service-->>Controller: 返回修改操作结果 Controller-->>ListJSP: 修改成功，跳转 User->>ListJSP: 查看再次更新后的学生列表 User->>ListJSP: 点击某行删除链接 ListJSP->>Controller: 传递要删除学生标识 Controller->>Service: 调用服务层删除学生方法 Service->>DAO: 调用数据访问层删除学生方法 DAO->>SQLiteDB: 执行SQL删除操作删除学生数据 SQLiteDB-->>DAO: 返回操作结果 DAO-->>Service: 返回删除操作结果 Service-->>Controller: 返回删除操作结果 Controller-->>ListJSP: 删除成功，跳转 User->>ListJSP: 查看最终的学生列表

创建列表页面：stu/list.jsp，显示学生列表，参考代码如下：

stu/list.jsp
<%@ page import="xust.demo.Result" %>
<%@ page import="xust.demo.stu.domain.Student" %>
<%@ page import="xust.demo.stu.service.StudentService" %>
<%@ page import="xust.demo.stu.service.StudentServiceImpl" %>
<%@ page import="java.util.ArrayList" %>
<%@ page import="java.util.List" %>
<%@ page contentType="text/html;charset=utf-8" %>
<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <title>学生表</title>
</head>

<body>
  <h3>学生表</h3>
  <a href="<%=request.getContextPath()%>/stu/add_view.jsp">新增</a>
  <table id="STUDENT" border="1" width="100%">
    <thead>
      <th>学号</th>
      <th>姓名</th>
      <th>性别</th>
      <th>年龄</th>
      <th>所在系</th>
      <th>操作</th>
    </thead>
    <tbody>
        <%
        StudentService _StudentService = new StudentServiceImpl();
        List<Student> students = (List<Student>)(_StudentService.getAll().data);

        if(students != null){
            for(Student stu: students){
                String line = "";
                line += String.format("<td>%s</td>", stu.getNo());
                line += String.format("<td>%s</td>", stu.getName());
                line += String.format("<td>%s</td>", stu.getGender());
                line += String.format("<td>%s</td>", stu.getAge());
                line += String.format("<td>%s</td>", stu.getDept());
                line += String.format("<td><a href='%s/stu/update_view.jsp?no=%s'>修改</a>&nbsp;&nbsp;<a href='%s/stu/delete.jsp?no=%s'>删除</a></td>", request.getContextPath(), stu.getNo(), request.getContextPath(), stu.getNo());
              out.print(String.format("<tr>%s</tr>", line));            
            }
        }
        %>
    </tbody>
  </table>
</body>

</html>

创建新建界面页面：stu/add_view.jsp，用于添加界面，参考代码如下：

stu/add_view.jsp
<%@ page contentType="text/html;charset=utf-8" %>
<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <title>学生表</title>
</head>

<body>
  <h3>学生表</h3>
  <div>
    <form action="<%=String.format(" %s/stu/add.jsp", request.getContextPath())%>">
      <div>
        <label for="no">学号:</label>
        <input type="text" id="no" name="no" placeholder="请输入学号..">
      </div>
      <div>
        <label for="name">姓名:</label>
        <input type="text" id="name" name="name" placeholder="请输入姓名..">
      </div>
      <div>
        <label for="gender">性别:</label>
        <input type="text" id="gender" name="gender" placeholder="请输入性别..">
      </div>
      <div>
        <label for="age">年龄:</label>
        <input type="number" id="age" name="age" placeholder="请输入年龄..">
      </div>
      <div>
        <label for="dept">所在系:</label>
        <input type="text" id="dept" name="dept" placeholder="请输入所在系..">
      </div>
      <button type="submit">提交</button>
    </form>
  </div>
</body>

</html>

创建新建页面：stu/add.jsp，实现添加功能，参考代码如下：

stu/add.jsp
<%@ page import="xust.demo.Result" %>
<%@ page import="xust.demo.stu.domain.Student" %>
<%@ page import="xust.demo.stu.service.StudentService" %>
<%@ page import="xust.demo.stu.service.StudentServiceImpl" %>
<%@ page import="java.util.ArrayList" %>
<%@ page import="java.util.List" %>
<%@ page contentType="text/html;charset=utf-8" %>
<%
StudentService _StudentService = new StudentServiceImpl();
Student stu_new = new Student();
Student o = _StudentService.toO(request);
Result res = _StudentService.create(o);

//操作完成，回到列表
response.sendRedirect(String.format("%s%s", request.getContextPath(), "/stu/list.jsp"));
%>

创建修改界面页面：stu/update_view.jsp，用于修改界面，参考代码如下：

stu/update_view.jsp
<%@ page import="xust.demo.Result"%>
<%@ page import="xust.demo.stu.domain.Student"%>
<%@ page import="xust.demo.stu.service.StudentService"%>
<%@ page import="xust.demo.stu.service.StudentServiceImpl"%>
<%@ page import="java.util.ArrayList"%>
<%@ page import="java.util.List"%>
<%@ page contentType="text/html;charset=utf-8"%>
<!DOCTYPE html>
<html>

<head>
<meta charset="utf-8">
<title>学生表</title>
</head>

<body>
    <h3>学生表</h3>
    <%
    StudentService _StudentService = new StudentServiceImpl();
    Student stu = (Student)_StudentService.get(request.getParameter("no")).data;

    if (stu == null) {
        stu = new Student();
    }
    %>
    <div>
        <form
            action="<%=String.format("%s/stu/update.jsp", request.getContextPath())%>">
            <div>
                <label for="no">学号:</label> <input type="text" id="no" name="no"
                    placeholder="请输入学号.." value="<%=stu.getNo()%>" readonly="true">
            </div>
            <div>
                <label for="name">姓名:</label> <input type="text" id="name"
                    name="name" placeholder="请输入姓名.." value="<%=stu.getName()%>">
            </div>
            <div>
                <label for="gender">性别:</label> <input type="text" id="gender"
                    name="gender" placeholder="请输入性别.." value="<%=stu.getGender()%>">
            </div>
            <div>
                <label for="age">年龄:</label> <input type="number" id="age"
                    name="age" placeholder="请输入年龄.." value="<%=stu.getAge()%>">
            </div>
            <div>
                <label for="dept">所在系:</label> <input type="text" id="dept"
                    name="dept" placeholder="请输入所在系.." value="<%=stu.getDept()%>">
            </div>
            <button type="submit">提交</button>
        </form>
    </div>
</body>

</html>

创建修改页面：stu/update.jsp，实现修改功能，参考代码如下：

stu/update.jsp
<%@ page import="xust.demo.Result"%>
<%@ page import="xust.demo.stu.domain.Student"%>
<%@ page import="xust.demo.stu.service.StudentService"%>
<%@ page import="xust.demo.stu.service.StudentServiceImpl"%>
<%@ page import="java.util.ArrayList"%>
<%@ page import="java.util.List"%>
<%@ page contentType="text/html;charset=utf-8"%>
<%
StudentService _StudentService = new StudentServiceImpl();
Student stu_new = new Student();
Student o = _StudentService.toO(request);
Result res = _StudentService.update(o);

//操作完成，回到列表
response.sendRedirect(String.format("%s%s", request.getContextPath(), "/stu/list.jsp"));
%>

创建删除页面：stu/delete.jsp，实现删除功能，参考代码如下：

stu/delete.jsp
<%@ page import="xust.demo.Result"%>
<%@ page import="xust.demo.stu.domain.Student"%>
<%@ page import="xust.demo.stu.service.StudentService"%>
<%@ page import="xust.demo.stu.service.StudentServiceImpl"%>
<%@ page import="java.util.ArrayList"%>
<%@ page import="java.util.List"%>
<%@ page contentType="text/html;charset=utf-8"%>
<%
StudentService _StudentService = new StudentServiceImpl();
Result res = _StudentService.delete(request.getParameter("no"));

//操作完成，回到列表
response.sendRedirect(String.format("%s%s", request.getContextPath(), "/stu/list.jsp"));
%>

测试全部功能

拓展练习

使用JSP实现课程表的增、删、改、查操作