基本流程：JSP文件显示页面，在前端页面输入赋值，使用form或href超链接传值到Servlet中方法，在Servlet方法中调用Dao层的类对象，将数据传到数据库中，并实现对数据库里的数据的增删改查，完成后将值重新返回到JSP输出操作结果数据。

共分为五个包和对应的JSP文件：

1.Util包：建立连接数据库的方法，以及关闭操作数据库的方法。

  1. package Util;
  2.  
  3. import java.sql.Connection;
  4. import java.sql.DriverManager;
  5. import java.sql.PreparedStatement;
  6. import java.sql.ResultSet;
  7. import java.sql.SQLException;
  8. import java.sql.Statement;
  9.  
  10. /**
  11.  * 数据库连接工具
  12.  * @author Hu
  13.  *
  14.  */
  15. public class DBUtil {
  16.  
  17.     public static String db_url = "jdbc:mysql://localhost:3306/course?useUnicode=true&characterEncoding=UTF-8";
  18.     public static String db_user = "root";
  19.     public static String db_pass = "root";
  20.  
  21.     public static Connection getConn () {
  22.         Connection conn = null;
  23.  
  24.         try {
  25.             Class.forName("com.mysql.jdbc.Driver");//加载驱动
  26.             conn = DriverManager.getConnection(db_url, db_user, db_pass);
  27.         } catch (Exception e) {
  28.             e.printStackTrace();
  29.         }
  30.  
  31.         return conn;
  32.     }
  33.  
  34.     /**
  35.      * 关闭连接
  36.      * @param state
  37.      * @param conn
  38.      */
  39.     public static void close (Statement state, Connection conn) {
  40.         if (state != null) {
  41.             try {
  42.                 state.close();
  43.             } catch (SQLException e) {
  44.                 e.printStackTrace();
  45.             }
  46.         }
  47.  
  48.         if (conn != null) {
  49.             try {
  50.                 conn.close();
  51.             } catch (SQLException e) {
  52.                 e.printStackTrace();
  53.             }
  54.         }
  55.     }
  56.  
  57.     public static void close (ResultSet rs, Statement state, Connection conn) {
  58.         if (rs != null) {
  59.             try {
  60.                 rs.close();
  61.             } catch (SQLException e) {
  62.                 e.printStackTrace();
  63.             }
  64.         }
  65.  
  66.         if (state != null) {
  67.             try {
  68.                 state.close();
  69.             } catch (SQLException e) {
  70.                 e.printStackTrace();
  71.             }
  72.         }
  73.  
  74.         if (conn != null) {
  75.             try {
  76.                 conn.close();
  77.             } catch (SQLException e) {
  78.                 e.printStackTrace();
  79.             }
  80.         }
  81.     }
  82.  
  83.     public static void main(String[] args) throws SQLException {
  84.         Connection conn = getConn();
  85.         PreparedStatement pstmt = null;
  86.         ResultSet rs = null;
  87.         String sql ="select * from course";
  88.         pstmt = conn.prepareStatement(sql);
  89.         rs = pstmt.executeQuery();
  90.         if(rs.next()){
  91.             System.out.println("空");
  92.         }else{
  93.             System.out.println("不空");
  94.         }
  95.     }
  96. }

2.Servlet包：①接受来自JSP页面的参数，将这些参数收集起来。②将Dao层传回来的操作结果返回到JSP页面显示。

  1. package Servlet;
  2.  
  3. import java.io.IOException;
  4. import java.util.List;
  5.  
  6. import javax.servlet.ServletException;
  7. import javax.servlet.annotation.WebServlet;
  8. import javax.servlet.http.HttpServlet;
  9. import javax.servlet.http.HttpServletRequest;
  10. import javax.servlet.http.HttpServletResponse;
  11.  
  12. import Javabean.Course;
  13. import Service.CourseService;
  14.  
  15. @WebServlet("/CourseServlet")
  16. public class CourseServlet extends HttpServlet {
  17.  
  18.     private static final long serialVersionUID = 1L;
  19.  
  20.     CourseService service = new CourseService();
  21.  
  22.     /**
  23.      * 方法选择
  24.      */
  25.     protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
  26.         req.setCharacterEncoding("utf-8");
  27.         String method = req.getParameter("method");
  28.  
  29.         if ("add".equals(method)) {
  30.             add(req, resp);
  31.         } else if ("del".equals(method)) {
  32.             del(req, resp);
  33.         } else if ("update".equals(method)) {
  34.             update(req, resp);
  35.         } else if ("search".equals(method)) {
  36.             search(req, resp);
  37.         } else if ("getcoursebyid".equals(method)) {
  38.             getCourseById(req, resp);
  39.         } else if ("getcoursebyname".equals(method)) {
  40.             getCourseByName(req, resp);
  41.         } else if ("list".equals(method)) {
  42.             list(req, resp);
  43.         }
  44.     }
  45.  
  46.     /**
  47.      * 添加
  48.      * @param req
  49.      * @param resp
  50.      * @throws IOException
  51.      * @throws ServletException
  52.      */
  53.     private void add(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
  54.         req.setCharacterEncoding("utf-8");
  55.         //获取数据
  56.         String name = req.getParameter("name");
  57.         String teacher = req.getParameter("teacher");
  58.         String classroom = req.getParameter("classroom");
  59.         Course course = new Course(name, teacher, classroom);
  60.         System.out.println(name+"  "+teacher);
  61.         //添加后消息显示
  62.         if(service.add(course)) {
  63.             req.setAttribute("message", "添加成功");
  64.             req.getRequestDispatcher("add.jsp").forward(req,resp);
  65.         } else {
  66.             req.setAttribute("message", "课程名称重复，请重新录入");
  67.             req.getRequestDispatcher("add.jsp").forward(req,resp);
  68.         }
  69.     }
  70.  
  71.     /**
  72.      * 全部
  73.      * @param req
  74.      * @param resp
  75.      * @throws ServletException
  76.      */
  77.     private void list(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
  78.         req.setCharacterEncoding("utf-8");
  79.  
  80.         List<Course> courses = service.list();
  81.         req.setAttribute("courses", courses);
  82.         req.getRequestDispatcher("list.jsp").forward(req,resp);
  83.     }
  84.  
  85.     /**
  86.      * 通过ID得到Course
  87.      * @param req
  88.      * @param resp
  89.      * @throws ServletException
  90.      */
  91.     private void getCourseById(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
  92.         req.setCharacterEncoding("utf-8");
  93.         int id = Integer.parseInt(req.getParameter("id"));
  94.         Course course = service.getCourseById(id);
  95.         req.setAttribute("course", course);
  96.         req.getRequestDispatcher("detail2.jsp").forward(req,resp);
  97.     }
  98.  
  99.     /**
  100.      * 通过名字查找
  101.      * 跳转至删除
  102.      * @param req
  103.      * @param resp
  104.      * @throws IOException
  105.      * @throws ServletException
  106.      */
  107.     private void getCourseByName(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
  108.         req.setCharacterEncoding("utf-8");
  109.         String name = req.getParameter("name");
  110.         Course course = service.getCourseByName(name);
  111.         if(course == null) {
  112.             req.setAttribute("message", "查无此课程！");
  113.             req.getRequestDispatcher("del.jsp").forward(req,resp);
  114.         } else {
  115.             req.setAttribute("course", course);
  116.             req.getRequestDispatcher("detail.jsp").forward(req,resp);
  117.         }
  118.     }
  119.  
  120.     /**
  121.      * 删除
  122.      * @param req
  123.      * @param resp
  124.      * @throws IOException
  125.      * @throws ServletException
  126.      */
  127.     private void del(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
  128.         req.setCharacterEncoding("utf-8");
  129.         int id = Integer.parseInt(req.getParameter("id"));
  130.         service.del(id);
  131.         req.setAttribute("message", "删除成功！");
  132.         req.getRequestDispatcher("del.jsp").forward(req,resp);
  133.     }
  134.  
  135.     /**
  136.      * 修改
  137.      * @param req
  138.      * @param resp
  139.      * @throws IOException
  140.      * @throws ServletException
  141.      */
  142.     private void update(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
  143.         req.setCharacterEncoding("utf-8");
  144.         int id = Integer.parseInt(req.getParameter("id"));
  145.         String name = req.getParameter("name");
  146.         String teacher = req.getParameter("teacher");
  147.         String classroom = req.getParameter("classroom");
  148.         Course course = new Course(id, name, teacher, classroom);
  149.  
  150.         service.update(course);
  151.         req.setAttribute("message", "修改成功");
  152.         req.getRequestDispatcher("CourseServlet?method=list").forward(req,resp);
  153.     }
  154.  
  155.     /**
  156.      * 查找
  157.      * @param req
  158.      * @param resp
  159.      * @throws ServletException
  160.      */
  161.     private void search(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
  162.         req.setCharacterEncoding("utf-8");
  163.         String name = req.getParameter("name");
  164.         String teacher = req.getParameter("teacher");
  165.         String classroom = req.getParameter("classroom");
  166.         List<Course> courses = service.search(name, teacher, classroom);
  167.         req.setAttribute("courses", courses);
  168.         req.getRequestDispatcher("searchlist.jsp").forward(req,resp);
  169.     }
  170. }

3.Javabean包：定义一个Course类，将要操作的对象归纳出他的属性和get，set方法。

  1. package Javabean;
  2.  
  3. public class Course {
  4.  
  5.     private int id;
  6.     private String name;
  7.     private String teacher;
  8.     private String classroom;
  9.  
  10.     public int getId() {
  11.         return id;
  12.     }
  13.     public void setId(int id) {
  14.         this.id = id;
  15.     }
  16.     public String getName() {
  17.         return name;
  18.     }
  19.     public void setName(String name) {
  20.         this.name = name;
  21.     }
  22.     public String getTeacher() {
  23.         return teacher;
  24.     }
  25.     public void setTeacher(String teacher) {
  26.         this.teacher = teacher;
  27.     }
  28.     public String getClassroom() {
  29.         return classroom;
  30.     }
  31.     public void setClassroom(String classroom) {
  32.         this.classroom = classroom;
  33.     }
  34.  
  35.     public Course() {}
  36.  
  37.     public Course(int id, String name, String teacher, String classroom) {
  38.         this.id = id;
  39.         this.name = name;
  40.         this.teacher = teacher;
  41.         this.classroom = classroom;
  42.     }
  43.  
  44.     public Course(String name, String teacher, String classroom) {
  45.         this.name = name;
  46.         this.teacher = teacher;
  47.         this.classroom = classroom;
  48.     }
  49. }

4.Dao层包：最主要的包，在这里通过Util包链接数据库，进行对数据库中的数据的增删改查，主要运用了数据库语言。

  1. package Dao;
  2.  
  3. import java.sql.Connection;
  4. import java.sql.ResultSet;
  5. import java.sql.SQLException;
  6. import java.sql.Statement;
  7. import java.util.ArrayList;
  8. import java.util.List;
  9.  
  10. import Javabean.Course;
  11. import Util.DBUtil;
  12.  
  13. /**
  14.  * 课程Dao
  15.  * Dao层操作数据
  16.  * @author Hu
  17.  *
  18.  */
  19. public class CourseDao {
  20.  
  21.     /**
  22.      * 添加
  23.      * @param course
  24.      * @return
  25.      */
  26.     public boolean add(Course course) {
  27.         System.out.println(course.getTeacher());
  28.         String sql = "insert into course(name, teacher, classroom) values('" + course.getName() + "','" + course.getTeacher() + "','" + course.getClassroom() + "')";
  29.         //创建数据库链接
  30.         Connection conn = DBUtil.getConn();
  31.         Statement state = null;
  32.         boolean f = false;
  33.         int a = 0;
  34.  
  35.         try {
  36.             state = conn.createStatement();
  37.             state.executeUpdate(sql);
  38.         } catch (Exception e) {
  39.             e.printStackTrace();
  40.         } finally {
  41.             //关闭连接
  42.             DBUtil.close(state, conn);
  43.         }
  44.  
  45.         if (a > 0) {
  46.             f = true;
  47.         }
  48.         return f;
  49.     }
  50.  
  51.     /**
  52.      * 删除
  53.      *
  54.      * @param id
  55.      * @return
  56.      */
  57.     public boolean delete (int id) {
  58.         boolean f = false;
  59.         String sql = "delete from course where id='" + id + "'";
  60.  
  61.         Connection conn = DBUtil.getConn();
  62.         Statement state = null;
  63.         int a = 0;
  64.  
  65.         try {
  66.             state = conn.createStatement();
  67.             a = state.executeUpdate(sql);
  68.         } catch (SQLException e) {
  69.             e.printStackTrace();
  70.         } finally {
  71.             DBUtil.close(state, conn);
  72.         }
  73.  
  74.         if (a > 0) {
  75.             f = true;
  76.         }
  77.         return f;
  78.     }
  79.  
  80.     /**
  81.      * 修改
  82.      * @param name
  83.      * @param pass
  84.      */
  85.     public boolean update(Course course) {
  86.         String sql = "update course set name='" + course.getName() + "', teacher='" + course.getTeacher() + "', classroom='" + course.getClassroom()
  87.             + "' where id='" + course.getId() + "'";
  88.         Connection conn = DBUtil.getConn();
  89.         Statement state = null;
  90.         boolean f = false;
  91.         int a = 0;
  92.  
  93.         try {
  94.             state = conn.createStatement();
  95.             a = state.executeUpdate(sql);
  96.         } catch (SQLException e) {
  97.             e.printStackTrace();
  98.         } finally {
  99.             DBUtil.close(state, conn);
  100.         }
  101.  
  102.         if (a > 0) {
  103.             f = true;
  104.         }
  105.         return f;
  106.     }
  107.  
  108.     /**
  109.      * 验证课程名称是否唯一
  110.      * true --- 不唯一
  111.      * @param name
  112.      * @return
  113.      */
  114.     public boolean name(String name) {
  115.         boolean flag = false;
  116.         String sql = "select name from course where name = '" + name + "'";
  117.         Connection conn = DBUtil.getConn();
  118.         Statement state = null;
  119.         ResultSet rs = null;
  120.  
  121.         try {
  122.             state = conn.createStatement();
  123.             rs = state.executeQuery(sql);
  124.             while (rs.next()) {
  125.                 flag = true;
  126.             }
  127.         } catch (SQLException e) {
  128.             e.printStackTrace();
  129.         } finally {
  130.             DBUtil.close(rs, state, conn);
  131.         }
  132.         return flag;
  133.     }
  134.  
  135.     /**
  136.      * 通过ID得到课程信息
  137.      * @param id
  138.      * @return
  139.      */
  140.     public Course getCourseById(int id) {
  141.         String sql = "select * from course where id ='" + id + "'";
  142.         Connection conn = DBUtil.getConn();
  143.         Statement state = null;
  144.         ResultSet rs = null;
  145.         Course course = null;
  146.  
  147.         try {
  148.             state = conn.createStatement();
  149.             rs = state.executeQuery(sql);
  150.             while (rs.next()) {
  151.                 String name = rs.getString("name");
  152.                 String teacher = rs.getString("teacher");
  153.                 String classroom = rs.getString("classroom");
  154.                 course = new Course(id, name, teacher, classroom);
  155.             }
  156.         } catch (Exception e) {
  157.             e.printStackTrace();
  158.         } finally {
  159.             DBUtil.close(rs, state, conn);
  160.         }
  161.  
  162.         return course;
  163.     }
  164.  
  165.     /**
  166.      * 通过name得到Course
  167.      * @param name
  168.      * @return
  169.      */
  170.     public Course getCourseByName(String name) {
  171.         String sql = "select * from course where name ='" + name + "'";
  172.         Connection conn = DBUtil.getConn();
  173.         Statement state = null;
  174.         ResultSet rs = null;
  175.         Course course = null;
  176.  
  177.         try {
  178.             state = conn.createStatement();
  179.             rs = state.executeQuery(sql);
  180.             while (rs.next()) {
  181.                 int id = rs.getInt("id");
  182.                 String teacher = rs.getString("teacher");
  183.                 String classroom = rs.getString("classroom");
  184.                 course = new Course(id, name, teacher, classroom);
  185.             }
  186.         } catch (Exception e) {
  187.             e.printStackTrace();
  188.         } finally {
  189.             DBUtil.close(rs, state, conn);
  190.         }
  191.  
  192.         return course;
  193.     }
  194.  
  195.     /**
  196.      * 查找
  197.      * @param name
  198.      * @param teacher
  199.      * @param classroom
  200.      * @return
  201.      */
  202.     public List<Course> search(String name, String teacher, String classroom) {
  203.         String sql = "select * from course where ";
  204.         if (name != "") {
  205.             sql += "name like '%" + name + "%'";
  206.         }
  207.         if (teacher != "") {
  208.             sql += "teacher like '%" + teacher + "%'";
  209.         }
  210.         if (classroom != "") {
  211.             sql += "classroom like '%" + classroom + "%'";
  212.         }
  213.         List<Course> list = new ArrayList<>();
  214.         Connection conn = DBUtil.getConn();
  215.         Statement state = null;
  216.         ResultSet rs = null;
  217.  
  218.         try {
  219.             state = conn.createStatement();
  220.             rs = state.executeQuery(sql);
  221.             Course bean = null;
  222.             while (rs.next()) {
  223.                 int id = rs.getInt("id");
  224.                 String name2 = rs.getString("name");
  225.                 String teacher2 = rs.getString("teacher");
  226.                 String classroom2 = rs.getString("classroom");
  227.                 bean = new Course(id, name2, teacher2, classroom2);
  228.                 list.add(bean);
  229.             }
  230.         } catch (SQLException e) {
  231.             e.printStackTrace();
  232.         } finally {
  233.             DBUtil.close(rs, state, conn);
  234.         }
  235.  
  236.         return list;
  237.     }
  238.  
  239.     /**
  240.      * 全部数据
  241.      * @param name
  242.      * @param teacher
  243.      * @param classroom
  244.      * @return
  245.      */
  246.     public List<Course> list() {
  247.         String sql = "select * from course";
  248.         List<Course> list = new ArrayList<>();
  249.         Connection conn = DBUtil.getConn();
  250.         Statement state = null;
  251.         ResultSet rs = null;
  252.  
  253.         try {
  254.             state = conn.createStatement();
  255.             rs = state.executeQuery(sql);
  256.             Course bean = null;
  257.             while (rs.next()) {
  258.                 int id = rs.getInt("id");
  259.                 String name2 = rs.getString("name");
  260.                 String teacher2 = rs.getString("teacher");
  261.                 String classroom2 = rs.getString("classroom");
  262.                 bean = new Course(id, name2, teacher2, classroom2);
  263.                 list.add(bean);
  264.             }
  265.         } catch (SQLException e) {
  266.             e.printStackTrace();
  267.         } finally {
  268.             DBUtil.close(rs, state, conn);
  269.         }
  270.  
  271.         return list;
  272.     }
  273.  
  274. }

5.Service包：通过Dao包实现数据库的增删改查。

  1. package Service;
  2.  
  3. import java.util.List;
  4.  
  5. import Dao.CourseDao;
  6. import Javabean.Course;
  7.  
  8. /**
  9.  * CourseService
  10.  * 服务层
  11.  * @author Hu
  12.  *
  13.  */
  14. public class CourseService {
  15.  
  16.     CourseDao cDao = new CourseDao();
  17.  
  18.     /**
  19.      * 添加
  20.      * @param course
  21.      * @return
  22.      */
  23.     public boolean add(Course course) {
  24.         boolean f = false;
  25.         if(!cDao.name(course.getName())) {
  26.             cDao.add(course);
  27.             f = true;
  28.         }
  29.         return f;
  30.     }
  31.  
  32.     /**
  33.      * 删除
  34.      */
  35.     public void del(int id) {
  36.         cDao.delete(id);
  37.     }
  38.  
  39.     /**
  40.      * 修改
  41.      * @return
  42.      */
  43.     public void update(Course course) {
  44.         cDao.update(course);
  45.     }
  46.  
  47.     /**
  48.      * 通过ID得到一个Course
  49.      * @return
  50.      */
  51.     public Course getCourseById(int id) {
  52.         return cDao.getCourseById(id);
  53.     }
  54.  
  55.     /**
  56.      * 通过Name得到一个Course
  57.      * @return
  58.      */
  59.     public Course getCourseByName(String name) {
  60.         return cDao.getCourseByName(name);
  61.     }
  62.  
  63.     /**
  64.      * 查找
  65.      * @return
  66.      */
  67.     public List<Course> search(String name, String teacher, String classroom) {
  68.         return cDao.search(name, teacher, classroom);
  69.     }
  70.  
  71.     /**
  72.      * 全部数据
  73.      * @return
  74.      */
  75.     public List<Course> list() {
  76.         return cDao.list();
  77.     }
  78. }

功能一:增加

在首页中选择功能添加信息，通过href超链接跳转到添加add.JSP页面，在add.JSP页面中的Form表格中输入要添加的相应的信息，通过Form表格的提交按钮将输入框Input中的内容和值（该值确定调用Servlet中的add方法）传给Servlet，在Servlet中调用add方法，在该方法中调用的Dao层中的add方法，Dao层中的add方法，该方法通过DB层获取与数据库的连接，对数据库进行数据添加的功能，之后返回操作结果给Servlet的add方法，由Servlet中的add方法判断输出添加成功的JSP信息页面。

  1. <%@ page language="java" contentType="text/html; charset=UTF-8"
  2.     pageEncoding="UTF-8"%>
  3. <!DOCTYPE html>
  4. <html>
  5. <head>
  6. <meta charset="UTF-8">
  7. <title>Insert title here</title>
  8.  
  9. </head>
  10. <body>
  11.     <%
  12.          Object message = request.getAttribute("message");
  13.          if(message!=null && !"".equals(message)){
  14.  
  15.     %>
  16.          <script type="text/javascript">
  17.               alert("<%=request.getAttribute("message")%>");
  18.          </script>
  19.     <%} %>
  20.     <div align="center">
  21.         <h1 style="color: black;">课程信息录入</h1>
  22.         <a href="index.jsp">返回主页</a>
  23.         <form action="CourseServlet?method=add" method="post" onsubmit="return check()">
  24.             <div class="a">
  25.                 课程名称<input type="text" id="name" name="name"/>
  26.             </div>
  27.             <div class="a">
  28.                 任课教师<input type="text" id="teacher" name="teacher" />
  29.             </div>
  30.             <div class="a">
  31.                 上课地点<input type="text" id="classroom" name="classroom" />
  32.             </div>
  33.             <div class="a">
  34.                 <button type="submit" class="b">保&nbsp;&nbsp;&nbsp;存</button>
  35.             </div>
  36.         </form>
  37.     </div>
  38.     <script type="text/javascript">
  39.         function check() {
  40.             var name = document.getElementById("name");;
  41.             var teacher = document.getElementById("teacher");
  42.             var classroom = document.getElementById("classroom");
  43.  
  44.             //非空
  45.             if(name.value == '') {
  46.                 alert('课程名称为空');
  47.                 name.focus();
  48.                 return false;
  49.             }
  50.             if(teacher.value == '') {
  51.                 alert('教师为空');
  52.                 teacher.focus();
  53.                 return false;
  54.             }
  55.             if(classroom.value == '') {
  56.                 alert('上课地点为空');
  57.                 classroom.focus();
  58.                 return false;
  59.             }
  60.  
  61.             //教师
  62.             if(teacher.value != '王建民' && teacher.value != '王辉' && teacher.value != '刘丹' && teacher.value != '刘立嘉' && teacher.value != '杨子光'){
  63.                 alert('教师名称错误');
  64.                 return false;
  65.             }
  66.  
  67.             //教室
  68.             if(!/^基教/.test(classroom.value) && !/^一教/.test(classroom.value) && !/^二教/.test(classroom.value) && !/^三教/.test(classroom.value)) {
  69.                 alert('上课地点错误');
  70.                 return false;
  71.             }
  72.         }
  73.     </script>
  74. </body>
  75. </html>

功能二:删除

在首页中选择功能删除信息，通过href超链接跳转到删除del.JSP页面中，在该页面中输入要删除的课程名称，然后传值到Servlet中，在Servlet中通过调用Dao层的查询方法，在数据库中查找是否存在此课程，若存在，将课程全部信息存入List中传给Servlet，Servlet在用JSP文件显示该课程全部信息，用户在确定是否要删除，若要删除则继续传值给Servlet，调用Servlet中的删除del方法，该方法调用Dao层的delete函数，实现数据库中的数据的删除，将操作结果返回至Servlet中，在Servlet中判断输出一个JSP结果页面。

  1. <%@ page language="java" contentType="text/html; charset=UTF-8"
  2.     pageEncoding="UTF-8"%>
  3. <!DOCTYPE html>
  4. <html>
  5. <head>
  6. <meta charset="UTF-8">
  7. <title>Insert title here</title>
  8.  
  9. </head>
  10. <body>
  11.     <%
  12.          Object message = request.getAttribute("message");
  13.          if(message!=null && !"".equals(message)){
  14.  
  15.     %>
  16.          <script type="text/javascript">
  17.               alert("<%=request.getAttribute("message")%>");
  18.          </script>
  19.     <%} %>
  20.     <div align="center">
  21.         <h1 style="color: black;">课程信息删除</h1>
  22.         <a href="index.jsp">返回主页</a>
  23.         <form action="CourseServlet?method=getcoursebyname" method="post" onsubmit="return check()">
  24.             <div class="a">
  25.                 课程名称<input type="text" id="name" name="name"/>
  26.             </div>
  27.             <div class="a">
  28.                 <button type="submit" class="b">查&nbsp;&nbsp;&nbsp;找</button>
  29.             </div>
  30.         </form>
  31.     </div>
  32.     <script type="text/javascript">
  33.         function check() {
  34.             var name = document.getElementById("name");;
  35.  
  36.             //非空
  37.             if(name.value == '') {
  38.                 alert('课程名称为空');
  39.                 name.focus();
  40.                 return false;
  41.             }
  42.         }
  43.     </script>
  44. </body>
  45. </html>
  1. <%@ page language="java" contentType="text/html; charset=UTF-8"
  2.     pageEncoding="UTF-8"%>
  3. <!DOCTYPE html>
  4. <html>
  5. <head>
  6. <meta charset="UTF-8">
  7. <title>Insert title here</title>
  8. <style>
  9.     .a{
  10.         margin-top: 20px;
  11.     }
  12.     .b{
  13.         font-size: 20px;
  14.         width: 160px;
  15.         color: white;
  16.         background-color: greenyellow;
  17.     }
  18.     .tb, td {
  19.         border: 1px solid black;
  20.         font-size: 22px;
  21.     }
  22. </style>
  23. </head>
  24. <body>
  25.     <div align="center">
  26.         <h1 style="color: black;">课程信息删除</h1>
  27.         <a href="index.jsp">返回主页</a>
  28.         <table class="tb">
  29.             <tr>
  30.                 <td>课程名称</td>
  31.                 <td>${course.name}</td>
  32.             </tr>
  33.             <tr>
  34.                 <td>任课教师</td>
  35.                 <td>${course.teacher}</td>
  36.             </tr>
  37.             <tr>
  38.                 <td>上课地点</td>
  39.                 <td>${course.classroom}</td>
  40.             </tr>
  41.         </table>
  42.         <div class="a">
  43.             <a onclick="return check()" href="CourseServlet?method=del&id=${course.id}">删&nbsp;&nbsp;&nbsp;除</a>
  44.         </div>
  45.     </div>
  46.     <script type="text/javascript">
  47.         function check() {
  48.             if (confirm("真的要删除吗？")){
  49.                 return true;
  50.             }else{
  51.                 return false;
  52.             }
  53.         }
  54.     </script>
  55. </body>
  56. </html>
  1. <%@ page language="java" contentType="text/html; charset=UTF-8"
  2.     pageEncoding="UTF-8"%>
  3. <!DOCTYPE html>
  4. <html>
  5. <head>
  6. <meta charset="UTF-8">
  7. <title>Insert title here</title>
  8.  
  9. </head>
  10. <body>
  11.     <%
  12.          Object message = request.getAttribute("message");
  13.          if(message!=null && !"".equals(message)){
  14.  
  15.     %>
  16.          <script type="text/javascript">
  17.               alert("<%=request.getAttribute("message")%>");
  18.          </script>
  19.     <%} %>
  20.     <div align="center">
  21.         <h1 style="color: black;">课程信息修改</h1>
  22.         <a href="index.jsp">返回主页</a>
  23.         <form action="CourseServlet?method=update" method="post" onsubmit="return check()">
  24.             <div class="a">
  25.                 课程名称<input type="text" id="name" name="name" value="${course.name}"/>
  26.             </div>
  27.             <div class="a">
  28.                 任课教师<input type="text" id="teacher" name="teacher" value="${course.teacher}"/>
  29.             </div>
  30.             <div class="a">
  31.                 上课地点<input type="text" id="classroom" name="classroom" value="${course.classroom}"/>
  32.             </div>
  33.             <input type="hidden" id="id" name="id" value="${course.id}"/>
  34.             <div class="a">
  35.                 <button type="submit" class="b">修&nbsp;&nbsp;&nbsp;改</button>
  36.             </div>
  37.         </form>
  38.     </div>
  39.     <script type="text/javascript">
  40.         function check() {
  41.             var name = document.getElementById("name");;
  42.             var teacher = document.getElementById("teacher");
  43.             var classroom = document.getElementById("classroom");
  44.  
  45.             //非空
  46.             if(name.value == '') {
  47.                 alert('课程名称为空');
  48.                 name.focus();
  49.                 return false;
  50.             }
  51.             if(teacher.value == '') {
  52.                 alert('教师为空');
  53.                 teacher.focus();
  54.                 return false;
  55.             }
  56.             if(classroom.value == '') {
  57.                 alert('上课地点为空');
  58.                 classroom.focus();
  59.                 return false;
  60.             }
  61.  
  62.             //教师
  63.             if(teacher.value != '王建民' && teacher.value != '王辉' && teacher.value != '刘丹' && teacher.value != '刘立嘉' && teacher.value != '杨子光'){
  64.                 alert('教师名称错误');
  65.                 return false;
  66.             }
  67.  
  68.             //教室
  69.             if(!/^基教/.test(classroom.value) && !/^一教/.test(classroom.value) && !/^二教/.test(classroom.value) && !/^三教/.test(classroom.value)) {
  70.                 alert('上课地点错误');
  71.                 return false;
  72.             }
  73.         }
  74.     </script>
  75. </body>
  76. </html>

功能三:修改

在首页中选择功能修改信息，通过href超链接跳转到修改list.JSP页面中，显示全部的数据，点击要修改的一组数据，传值（此值为要修改的编号等 ）给Servlet，在Servlet中调用Dao层的update修改方法，update方法修改数据库中数据，将操作结果返回至Servlet中，由Servlet最终调用JSP弹出操作结果。

  1. <%@ page language="java" contentType="text/html; charset=UTF-8"
  2.     pageEncoding="UTF-8"%>
  3. <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
  4. <!DOCTYPE html>
  5. <html>
  6. <head>
  7. <meta charset="UTF-8">
  8. <title>Insert title here</title>
  9.  
  10. </head>
  11. <body>
  12.     <%
  13.          Object message = request.getAttribute("message");
  14.          if(message!=null && !"".equals(message)){
  15.  
  16.     %>
  17.          <script type="text/javascript">
  18.               alert("<%=request.getAttribute("message")%>");
  19.          </script>
  20.     <%} %>
  21.     <div align="center">
  22.         <h1 style="color: black;">课程信息列表</h1>
  23.         <a href="index.jsp">返回主页</a>
  24.         <table class="tb">
  25.             <tr>
  26.                 <td>id</td>
  27.                 <td>课程名称</td>
  28.                 <td>任课教师</td>
  29.                 <td>上课地点</td>
  30.                 <td align="center" colspan="2">操作</td>
  31.             </tr>
  32.             <c:forEach items="${courses}" var="item">
  33.                 <tr>
  34.                     <td>${item.id}</td>
  35.                     <td>${item.name}</td>
  36.                     <td>${item.teacher}</td>
  37.                     <td>${item.classroom}</td>
  38.                     <td><a href="CourseServlet?method=getcoursebyid&id=${item.id}">修改</a></td>
  39.                 </tr>
  40.             </c:forEach>
  41.         </table>
  42.     </div>
  43. </body>
  44. </html>

功能四:查找

在首页中选择功能查询信息，通过href超链接跳转到查询search.JSP页面中，在该页面中输入你要查询的信息，可进行粗略和精确查询，将输入的内容通过Form表格传值给Servlet，由Servlet中查询search方法调用Dao层的查询search方法，由此方法在数据库中进行模糊或者精确查询，将查询到的信息装在List中传给Servlet，最终由Servlet返回给JSP一个最终查询的信息。

  1.  

<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>

  1.  

</head>
<body>
<div align="center">
<h1 style="color: black;">课程信息查询</h1>
<a href="index.jsp">返回主页</a>
<form action="CourseServlet?method=search" method="post" onsubmit="return check()">
<div class="a">
课程名称<input type="text" id="name" name="name"/>
</div>
<div class="a">
任课教师<input type="text" id="teacher" name="teacher" />
</div>
<div class="a">
上课地点<input type="text" id="classroom" name="classroom" />
</div>
<div class="a">
<button type="submit" class="b">查&nbsp;&nbsp;&nbsp;询</button>
</div>
</form>
</div>
<script type="text/javascript">
function check() {
var name = document.getElementById("name");;
var teacher = document.getElementById("teacher");
var classroom = document.getElementById("classroom");

//非空
if(name.value == '' && teacher.value == '' && classroom.value == '') {
alert('请填写一个条件');
return false;
}
}
</script>
</body>
</html>

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