首先建立数据库的连接， 新建web项目，点击两次next，勾选自动生成web.xml，将连接mysql的驱动jar包（mysql-connector-java-8.0.13-bin.jar）复制到WEB-INF下的lib目录下。
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() + "')";
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 {
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得到类
* @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.util; import java.sql.Connection; import java.sql.DriverManager; 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?useSSL=false"; public static String db_user = "root"; public static String db_pass = "123456"; 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(); } } } }
<%@ 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; 160px; color: white; background-color: greenyellow; } </style> </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: red;">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> <style> .a{ margin-top: 20px; } .b{ font-size: 20px; 160px; color: white; background-color: greenyellow; } </style> </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: red;">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; 160px; color: white; background-color: greenyellow; } .tb, td { border: 1px solid black; font-size: 22px; } </style> </head> <body> <div align="center"> <h1 style="color: red;">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>Insert title here</title> <style> .a{ margin-top: 20px; } .b{ font-size: 20px; 160px; color: white; background-color: greenyellow; } </style> </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: red;">课程信息修改</h1> <a href="index.jsp">返回主页</a> <form action="CourseServlet?method=update" method="post" onsubmit="return check()"> <div class="a"> 课程名称<input type="text" id="name" name="name" value="${course.name}"/> </div> <div class="a"> 任课教师<input type="text" id="teacher" name="teacher" value="${course.teacher}"/> </div> <div class="a"> 上课地点<input type="text" id="classroom" name="classroom" value="${course.classroom}"/> </div> <input type="hidden" id="id" name="id" value="${course.id}"/> <div class="a"> <button type="submit" class="b">修 改</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>首页</title> <style> .a{ font-size: 26px; margin-top: 20px; } </style> </head> <body> <div align="center"> <h1 style="color: red;">课程基本信息管理系统</h1> <div class="a"> <a href="add.jsp">课程信息录入</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> <style> .a{ margin-top: 20px; } .b{ font-size: 20px; 160px; color: white; background-color: greenyellow; } .tb, td { border: 1px solid black; font-size: 22px; } </style> </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: red;">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> <style> .a{ margin-top: 20px; } .b{ font-size: 20px; 160px; color: white; background-color: greenyellow; } </style> </head> <body> <div align="center"> <h1 style="color: red;">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>
<%@ 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> <style> .a{ margin-top: 20px; } .b{ font-size: 20px; 160px; color: white; background-color: greenyellow; } .tb, td { border: 1px solid black; font-size: 22px; } </style> </head> <body> <div align="center"> <h1 style="color: red;">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>