一、【建立数据库】
在mysql中新建一个名为kecheng的数据库，并在其中新建一个kecheng数据表，包含三个字段，classname,classroom,teacher
二、【新建web项目】
1. eclipse新建一个名为Course的Dynamic Web Project
2. 将连接mysql的驱动jar包（mysql-connector-java-5.1.7-bin.jar）copy到WEB-INF下的lib目录下
3.新建五个包，entity存放实体类(User)，dao存放数据库操作类(UserDao)，servlet存放控制类(addServlet,updateServlet,deleteServlet,listServlet)，util存放开发帮助类
代码：
package com.hjf.dao;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import com.hjf.entity.Course;
import com.hjf.util.DBUtil;
/**
* 课程Dao
* Dao层操作数据
* @author Hu
*
*/
public class CourseDao {
/**
* 添加
* @param course
* @return
*/
public boolean add(Course course) {
String sql = "insert into course(name, teacher, classroom) values('" + course.getName() + "','" + course.getTeacher() + "','" + course.getClassroom() + "')";
//创建数据库链接
Connection conn = DBUtil.getConn();
Statement state = null;
boolean f = false;
int a = 0;
try {
state = conn.createStatement();
state.executeUpdate(sql);
} catch (Exception e) {
e.printStackTrace();
} finally {
//关闭连接
DBUtil.close(state, conn);
}
if (a > 0) {
f = true;
}
return f;
}
/**
* 删除
*
* @param id
* @return
*/
public boolean delete (int id) {
boolean f = false;
String sql = "delete from course where id='" + id + "'";
Connection conn = DBUtil.getConn();
Statement state = null;
int a = 0;
try {
state = conn.createStatement();
a = state.executeUpdate(sql);
} catch (SQLException e) {
e.printStackTrace();
} finally {
DBUtil.close(state, conn);
}
if (a > 0) {
f = true;
}
return f;
}
/**
* 修改
* @param name
* @param pass
*/
public boolean update(Course course) {
String sql = "update course set name='" + course.getName() + "', teacher='" + course.getTeacher() + "', classroom='" + course.getClassroom()
+ "' where id='" + course.getId() + "'";
Connection conn = DBUtil.getConn();
Statement state = null;
boolean f = false;
int a = 0;
try {
state = conn.createStatement();
a = state.executeUpdate(sql);
} catch (SQLException e) {
e.printStackTrace();
} finally {
DBUtil.close(state, conn);
}
if (a > 0) {
f = true;
}
return f;
}
/**
* 验证课程名称是否唯一
* true --- 不唯一
* @param name
* @return
*/
public boolean name(String name) {
boolean flag = false;
String sql = "select name from course where name = '" + name + "'";
Connection conn = DBUtil.getConn();
Statement state = null;
ResultSet rs = null;
try {
state = conn.createStatement();
rs = state.executeQuery(sql);
while (rs.next()) {
flag = true;
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
DBUtil.close(rs, state, conn);
}
return flag;
}
/**
* 通过ID得到课程信息
* @param id
* @return
*/
public Course getCourseById(int id) {
String sql = "select * from course where id ='" + id + "'";
Connection conn = DBUtil.getConn();
Statement state = null;
ResultSet rs = null;
Course course = null;
try {
state = conn.createStatement();
rs = state.executeQuery(sql);
while (rs.next()) {
String name = rs.getString("name");
String teacher = rs.getString("teacher");
String classroom = rs.getString("classroom");
course = new Course(id, name, teacher, classroom);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
DBUtil.close(rs, state, conn);
}
return course;
}
/**
* 通过name得到Course
* @param name
* @return
*/
public Course getCourseByName(String name) {
String sql = "select * from course where name ='" + name + "'";
Connection conn = DBUtil.getConn();
Statement state = null;
ResultSet rs = null;
Course course = null;
try {
state = conn.createStatement();
rs = state.executeQuery(sql);
while (rs.next()) {
int id = rs.getInt("id");
String teacher = rs.getString("teacher");
String classroom = rs.getString("classroom");
course = new Course(id, name, teacher, classroom);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
DBUtil.close(rs, state, conn);
}
return course;
}
/**
* 查找
* @param name
* @param teacher
* @param classroom
* @return
*/
public List<Course> search(String name, String teacher, String classroom) {
String sql = "select * from course where ";
if (name != "") {
sql += "name like '%" + name + "%'";
}
if (teacher != "") {
sql += "teacher like '%" + teacher + "%'";
}
if (classroom != "") {
sql += "classroom like '%" + classroom + "%'";
}
List<Course> list = new ArrayList<>();
Connection conn = DBUtil.getConn();
Statement state = null;
ResultSet rs = null;
try {
state = conn.createStatement();
rs = state.executeQuery(sql);
Course bean = null;
while (rs.next()) {
int id = rs.getInt("id");
String name2 = rs.getString("name");
String teacher2 = rs.getString("teacher");
String classroom2 = rs.getString("classroom");
bean = new Course(id, name2, teacher2, classroom2);
list.add(bean);
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
DBUtil.close(rs, state, conn);
}
return list;
}
/**
* 全部数据
* @param name
* @param teacher
* @param classroom
* @return
*/
public List<Course> list() {
String sql = "select * from course";
List<Course> list = new ArrayList<>();
Connection conn = DBUtil.getConn();
Statement state = null;
ResultSet rs = null;
try {
state = conn.createStatement();
rs = state.executeQuery(sql);
Course bean = null;
while (rs.next()) {
int id = rs.getInt("id");
String name2 = rs.getString("name");
String teacher2 = rs.getString("teacher");
String classroom2 = rs.getString("classroom");
bean = new Course(id, name2, teacher2, classroom2);
list.add(bean);
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
DBUtil.close(rs, state, conn);
}
return list;
}
}package com.hjf.entity;
public class Course {
private int id;
private String name;
private String teacher;
private String classroom;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getTeacher() {
return teacher;
}
public void setTeacher(String teacher) {
this.teacher = teacher;
}
public String getClassroom() {
return classroom;
}
public void setClassroom(String classroom) {
this.classroom = classroom;
}
public Course() {}
public Course(int id, String name, String teacher, String classroom) {
this.id = id;
this.name = name;
this.teacher = teacher;
this.classroom = classroom;
}
public Course(String name, String teacher, String classroom) {
this.name = name;
this.teacher = teacher;
this.classroom = classroom;
}
}package com.hjf.service;
import java.util.List;
import com.hjf.dao.CourseDao;
import com.hjf.entity.Course;
/**
* CourseService
* 服务层
* @author Hu
*
*/
public class CourseService {
CourseDao cDao = new CourseDao();
/**
* 添加
* @param course
* @return
*/
public boolean add(Course course) {
boolean f = false;
if(!cDao.name(course.getName())) {
cDao.add(course);
f = true;
}
return f;
}
/**
* 删除
*/
public void del(int id) {
cDao.delete(id);
}
/**
* 修改
* @return
*/
public void update(Course course) {
cDao.update(course);
}
/**
* 通过ID得到一个Course
* @return
*/
public Course getCourseById(int id) {
return cDao.getCourseById(id);
}
/**
* 通过Name得到一个Course
* @return
*/
public Course getCourseByName(String name) {
return cDao.getCourseByName(name);
}
/**
* 查找
* @return
*/
public List<Course> search(String name, String teacher, String classroom) {
return cDao.search(name, teacher, classroom);
}
/**
* 全部数据
* @return
*/
public List<Course> list() {
return cDao.list();
}
}package com.hjf.servlet;
import java.io.IOException;
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.hjf.entity.Course;
import com.hjf.service.CourseService;
@WebServlet("/CourseServlet")
public class CourseServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
CourseService service = new CourseService();
/**
* 方法选择
*/
protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("utf-8");
String method = req.getParameter("method");
if ("add".equals(method)) {
add(req, resp);
} else if ("del".equals(method)) {
del(req, resp);
} else if ("update".equals(method)) {
update(req, resp);
} else if ("search".equals(method)) {
search(req, resp);
} else if ("getcoursebyid".equals(method)) {
getCourseById(req, resp);
} else if ("getcoursebyname".equals(method)) {
getCourseByName(req, resp);
} else if ("list".equals(method)) {
list(req, resp);
}
}
/**
* 添加
* @param req
* @param resp
* @throws IOException
* @throws ServletException
*/
private void add(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
req.setCharacterEncoding("utf-8");
//获取数据
String name = req.getParameter("name");
String teacher = req.getParameter("teacher");
String classroom = req.getParameter("classroom");
Course course = new Course(name, teacher, classroom);
//添加后消息显示
if(service.add(course)) {
req.setAttribute("message", "添加成功");
req.getRequestDispatcher("add.jsp").forward(req,resp);
} else {
req.setAttribute("message", "课程名称重复，请重新录入");
req.getRequestDispatcher("add.jsp").forward(req,resp);
}
}
/**
* 全部
* @param req
* @param resp
* @throws ServletException
*/
private void list(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
req.setCharacterEncoding("utf-8");
List<Course> courses = service.list();
req.setAttribute("courses", courses);
req.getRequestDispatcher("list.jsp").forward(req,resp);
}
/**
* 通过ID得到Course
* @param req
* @param resp
* @throws ServletException
*/
private void getCourseById(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
req.setCharacterEncoding("utf-8");
int id = Integer.parseInt(req.getParameter("id"));
Course course = service.getCourseById(id);
req.setAttribute("course", course);
req.getRequestDispatcher("detail2.jsp").forward(req,resp);
}
/**
* 通过名字查找
* 跳转至删除
* @param req
* @param resp
* @throws IOException
* @throws ServletException
*/
private void getCourseByName(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
req.setCharacterEncoding("utf-8");
String name = req.getParameter("name");
Course course = service.getCourseByName(name);
if(course == null) {
req.setAttribute("message", "查无此课程！");
req.getRequestDispatcher("del.jsp").forward(req,resp);
} else {
req.setAttribute("course", course);
req.getRequestDispatcher("detail.jsp").forward(req,resp);
}
}
/**
* 删除
* @param req
* @param resp
* @throws IOException
* @throws ServletException
*/
private void del(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
req.setCharacterEncoding("utf-8");
int id = Integer.parseInt(req.getParameter("id"));
service.del(id);
req.setAttribute("message", "删除成功！");
req.getRequestDispatcher("del.jsp").forward(req,resp);
}
/**
* 修改
* @param req
* @param resp
* @throws IOException
* @throws ServletException
*/
private void update(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
req.setCharacterEncoding("utf-8");
int id = Integer.parseInt(req.getParameter("id"));
String name = req.getParameter("name");
String teacher = req.getParameter("teacher");
String classroom = req.getParameter("classroom");
Course course = new Course(id, name, teacher, classroom);
service.update(course);
req.setAttribute("message", "修改成功");
req.getRequestDispatcher("CourseServlet?method=list").forward(req,resp);
}
/**
* 查找
* @param req
* @param resp
* @throws ServletException
*/
private void search(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
req.setCharacterEncoding("utf-8");
String name = req.getParameter("name");
String teacher = req.getParameter("teacher");
String classroom = req.getParameter("classroom");
List<Course> courses = service.search(name, teacher, classroom);
req.setAttribute("courses", courses);
req.getRequestDispatcher("searchlist.jsp").forward(req,resp);
}
}package com.hjf.util;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
/**
* 数据库连接工具
* @author Hu
*
*/
public class DBUtil {
public static String db_url = "jdbc:mysql://localhost:3306/course?useUnicode=true&characterEncoding=utf8";
public static String db_user = "root";
public static String db_pass = "123";
public static Connection getConn () {
Connection conn = null;
try {
Class.forName("com.mysql.jdbc.Driver");//加载驱动
conn = DriverManager.getConnection(db_url, db_user, db_pass);
} catch (Exception e) {
e.printStackTrace();
}
return conn;
}
/**
* 关闭连接
* @param state
* @param conn
*/
public static void close (Statement 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, Statement state, Connection conn) {
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) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
public static void main(String[] args) throws SQLException {
Connection conn = getConn();
PreparedStatement pstmt = null;
ResultSet rs = null;
String sql ="select * from course";
pstmt = conn.prepareStatement(sql);
rs = pstmt.executeQuery();
if(rs.next()){
System.out.println("空");
}else{
System.out.println("不空");
}
}
}<%@ 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>
</head>
<body>
<%
Object message = request.getAttribute("message");
if(message!=null && !"".equals(message)){
%>
<script type="text/javascript">
alert("<%=request.getAttribute("message")%>");
</script>
<%} %>
<div align="center">
<h1 style="color: black;">课程信息录入</h1>
<a href="index.jsp">返回主页</a>
<form action="CourseServlet?method=add" 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">保 存</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 == '') {
alert('课程名称为空');
name.focus();
return false;
}
if(teacher.value == '') {
alert('教师为空');
teacher.focus();
return false;
}
if(classroom.value == '') {
alert('上课地点为空');
classroom.focus();
return false;
}
//教师
if(teacher.value != '王建民' && teacher.value != '王辉' && teacher.value != '刘丹' && teacher.value != '刘立嘉' && teacher.value != '杨子光'){
alert('教师名称错误');
return false;
}
//教室
if(!/^基教/.test(classroom.value) && !/^一教/.test(classroom.value) && !/^二教/.test(classroom.value) && !/^三教/.test(classroom.value)) {
alert('上课地点错误');
return false;
}
}
</script>
</body>
</html><%@ 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>
</head>
<body>
<%
Object message = request.getAttribute("message");
if(message!=null && !"".equals(message)){
%>
<script type="text/javascript">
alert("<%=request.getAttribute("message")%>");
</script>
<%} %>
<div align="center">
<h1 style="color: black;">课程信息删除</h1>
<a href="index.jsp">返回主页</a>
<form action="CourseServlet?method=getcoursebyname" method="post" onsubmit="return check()">
<div class="a">
课程名称<input type="text" id="name" name="name"/>
</div>
<div class="a">
<button type="submit" class="b">查 找</button>
</div>
</form>
</div>
<script type="text/javascript">
function check() {
var name = document.getElementById("name");;
//非空
if(name.value == '') {
alert('课程名称为空');
name.focus();
return false;
}
}
</script>
</body>
</html><%@ 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>
<style>
.a{
margin-top: 20px;
}
.b{
font-size: 20px;
width: 160px;
color: white;
background-color: greenyellow;
}
.tb, td {
border: 1px solid black;
font-size: 22px;
}
</style>
</head>
<body>
<div align="center">
<h1 style="color: black;">课程信息删除</h1>
<a href="index.jsp">返回主页</a>
<table class="tb">
<tr>
<td>课程名称</td>
<td>${course.name}</td>
</tr>
<tr>
<td>任课教师</td>
<td>${course.teacher}</td>
</tr>
<tr>
<td>上课地点</td>
<td>${course.classroom}</td>
</tr>
</table>
<div class="a">
<a onclick="return check()" href="CourseServlet?method=del&id=${course.id}">删 除</a>
</div>
</div>
<script type="text/javascript">
function check() {
if (confirm("真的要删除吗？")){
return true;
}else{
return false;
}
}
</script>
</body>
</html><%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>首页</title>
</head>
<body>
<div align="center">
<div class="a">
<a href="add.jsp">课程信息添加</a>
</div>
<div class="a">
<a href="CourseServlet?method=list">课程信息修改</a>
</div>
<div class="a">
<a href="del.jsp">课程信息删除</a>
</div>
<div class="a">
<a href="search.jsp">课程信息查询</a>
</div>
</div>
</body>
</html><%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<%
Object message = request.getAttribute("message");
if(message!=null && !"".equals(message)){
%>
<script type="text/javascript">
alert("<%=request.getAttribute("message")%>");
</script>
<%} %>
<div align="center">
<h1 style="color: black;">课程信息列表</h1>
<a href="index.jsp">返回主页</a>
<table class="tb">
<tr>
<td>id</td>
<td>课程名称</td>
<td>任课教师</td>
<td>上课地点</td>
<td align="center" colspan="2">操作</td>
</tr>
<c:forEach items="${courses}" var="item">
<tr>
<td>${item.id}</td>
<td>${item.name}</td>
<td>${item.teacher}</td>
<td>${item.classroom}</td>
<td><a href="CourseServlet?method=getcoursebyid&id=${item.id}">修改</a></td>
</tr>
</c:forEach>
</table>
</div>
</body>
</html><%@ 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>
</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 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><%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<div align="center">
<h1 style="color: black;">课程信息列表</h1>
<a href="index.jsp">返回主页</a>
<table class="tb">
<tr>
<td>id</td>
<td>课程名称</td>
<td>任课教师</td>
<td>上课地点</td>
</tr>
<!-- forEach遍历出adminBeans -->
<c:forEach items="${courses}" var="item" varStatus="status">
<tr>
<td>${item.id}</td>
<td><a>${item.name}</a></td>
<td>${item.teacher}</td>
<td>${item.classroom}</td>
</tr>
</c:forEach>
</table>
</div>
</body>
</html>
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