毕业设计 JavaWeb的学生信息管理系统

布满荆棘的人生 2024-02-27 03:55 85阅读 0赞

### 项目背景 ###

学生信息管理是学校的重要工作之一。传统的学生信息管理由于是手工操作，工作量大且容易出错。随着计算机和网络技术的迅速发展，越来越多的院校都拥有了自己的学生信息管理系统，而采用B/S架构的学生信息管理系统进行学生信息的管理则是其趋势。  
Java web技术的基础就是核心Java平台，它有许多优点，例如：“编写一次、随处运行”的特性、方便存取数据库的JDBC  
API技术以及能够在Internet应用中保护数据的安全模式等等。J2EE体系结构提供中间层集成框架用来满足高可用性、高可靠性以及可扩展性的应用需求，为搭建具有可伸缩性、灵活性、易维护性的网络应用系统提供了良好的机制。  
本文基于Java web平台技术、采用Browser/Server结构,设计并实现了该系统的简化版学生信息管理系统。  
论文首先介绍了系统开发涉及的相关技术及开发平台，主要围绕学生信息管理系统实现的相关技术和系统的体系结构，介绍了学生信息管理系统的总体分析与设计，包括需求分析、功能模块分析和数据库设计。最后，利用Jsp+Servlet+JavaBean模式对简单学生信息管理子系统进行了实现，并作了详细描述，主要采用图片与代码结合的方式详细地叙述了系统功能的实现。  
**关键词：** 学生信息管理系统，Java web，Servlet，JSP

### 功能设计 ###

##### 功能模块图 #####

系统结构图  
![在这里插入图片描述][watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBAU3RldmXooqvms6jlhozkuoY_size_20_color_FFFFFF_t_70_g_se_x_16]  
用户登录流程图  
![在这里插入图片描述][68293b8bf1ed4f64a21f1aea2e5fd3c2.png]  
程序流程图  
![在这里插入图片描述][61d792660188467aa535d513d989ead3.png]

### 功能截图 ###

![在这里插入图片描述][watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBAU3RldmXooqvms6jlhozkuoY_size_20_color_FFFFFF_t_70_g_se_x_16 1]  
![在这里插入图片描述][watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBAU3RldmXooqvms6jlhozkuoY_size_20_color_FFFFFF_t_70_g_se_x_16 2]  
![在这里插入图片描述][watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBAU3RldmXooqvms6jlhozkuoY_size_20_color_FFFFFF_t_70_g_se_x_16 3]

### 相关代码 ###

1public class LoginServlet extends HttpServlet {
        
        2	private static final long serialVersionUID = 1L;
        3	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
        4		request.setCharacterEncoding("utf-8");
        5		String username = request.getParameter("username");
        6		String password = request.getParameter("password");
        7		String level = null;
        8		//实例化UserDao对象
        9		UserDao userDao = new UserDao();
        10		User user = userDao.login(username, password);
        11		//判断是否登录成功
        12		if(user != null){
        //成功
        13			level = user.getLevel();
        14			if(level.equals("用户")){
        
        15				request.getSession().setAttribute("user", user);//将用户对象放到session中
        16				//转发到user.jsp中
        17				request.getRequestDispatcher("user.jsp").forward(request, response);
        18			}
        19			else{
        
        20			request.getSession().setAttribute("admin", user);//将管理员对象放到session中
        21				//转发到admin.jsp中
        22				request.getRequestDispatcher("admin.jsp").forward(request, response);
        23			}	
        24		}else {
        //失败
        25			request.setAttribute("info"," 错误:用户名或密码错误！");
        26			request.getRequestDispatcher("message.jsp").forward(request, response);
        27		}
        28	}
        }
    
    
        1public class CourseDao {
        
        2	// 获取所有课程的信息，用ArrayList返回
        3	public ArrayList<Course> query_all_course() {
        
        4		Connection conn = DBUtils.getConnection();
        5		String sql = "select * from course order by cno;";
        6		ArrayList<Course> results = new ArrayList<Course>();
        7		try {
        
        8			PreparedStatement ps = (PreparedStatement) conn.prepareStatement(sql);
        9			ResultSet rs = ps.executeQuery();
        10			while (rs.next()) {
        
        11				Course temp = new Course();
        12				temp.setCno(rs.getString("Cno"));
        13				temp.setCname(rs.getString("Cname"));
        14				temp.setCteacher(rs.getString("Cteacher"));
        15				temp.setCcredit(rs.getInt("Ccredit"));
        16				results.add(temp);
        17			}
        18			// 关闭资源
        19			rs.close();
        20			ps.close();
        21		} catch (SQLException e) {
        
        22			e.printStackTrace();
        23		} finally {
        
        24			DBUtils.closeConnection(conn);
        25		}
        26		return results;
        27	}
        28	// 插入课程信息，返回一个int值表示状态,1：成功，0失败
        29	public int insert_course(String Cno, String Cname, String Cteacher, double Ccredit) {
        
        30		Connection conn = DBUtils.getConnection();
        31		String sql = "insert into course values(?,?,?,?);";
        32		int flag = 0;
        33		try {
        
        34			PreparedStatement ps = (PreparedStatement) conn.prepareStatement(sql);
        35			ps.setString(1, Cno);
        36			ps.setString(2, Cname);
        37			ps.setString(3, Cteacher);
        38			ps.setDouble(4, Ccredit);
        39			flag = ps.executeUpdate();
        40			ps.close();
        41		} catch (SQLException e) {
        
        42			e.printStackTrace();
        43		} finally {
        
        44			DBUtils.closeConnection(conn);
        45		}
        46		return flag;
        47	}
        48	// 删除课程信息，返回一个int值表示状态,1：成功，0失败
        49	public int delete_course(String Cno) {
        
        50		Connection conn = DBUtils.getConnection();
        51		String sql = "delete from course where Cno = ?;";
        52		int flag = 0;
        53		try {
        
        54			PreparedStatement ps = (PreparedStatement) conn.prepareStatement(sql);
        55			ps.setString(1, Cno);
        56			flag = ps.executeUpdate();
        57			ps.close();
        58		} catch (SQLException e) {
        
        59			e.printStackTrace();
        60		} finally {
        
        61			DBUtils.closeConnection(conn);
        62		}
        63		return flag;
        64	}
        65	//修改课程信息，返回一个int值表示状态,1：成功，0失败
        66	public int alter_course(String cno,String after_cno,String after_cname,String after_cteacher,double after_ccredit) {
        
        67		Connection conn = DBUtils.getConnection();
        68		String sql = "update course set cno = ?,cname = ?,cteacher = ?,ccredit = ? where cno = ?;";
        69		int flag = 0;
        70		try {
        
        71			PreparedStatement ps = (PreparedStatement) conn.prepareStatement(sql);
        72			ps.setString(1, after_cno);
        73			ps.setString(2, after_cname);
        74			ps.setString(3, after_cteacher);
        75			ps.setDouble(4, after_ccredit);
        76			ps.setString(5, cno);
        77			flag = ps.executeUpdate();
        78			ps.close();
        79		} catch (SQLException e) {
        
        80			e.printStackTrace();
        81		}finally {
        
        82			DBUtils.closeConnection(conn);
        83		}
        84		return flag;
        85	}
        86	// 查询课程平均分信息，返回一个ArrayLst集合
        87	public ArrayList<Course_avg> course_avg() {
        
        88		Connection conn = DBUtils.getConnection();
        89		String sql = "select sc.cno cno,cname,avg(grade) avg from course,sc where course.cno = sc.cno group by cno order by cno;";
        90		ResultSet result = null;
        91		ArrayList<Course_avg> course_avg = new ArrayList<Course_avg>();
        92		try {
        
        93			PreparedStatement ps = (PreparedStatement) conn.prepareStatement(sql);
        94			result = ps.executeQuery();
        95			while(result.next()){
        
        96				Course_avg temp = new Course_avg();
        97				temp.setCno(result.getString("Cno"));
        98				temp.setCname(result.getString("Cname"));
        99				temp.setAvg(result.getDouble("avg"));
        100				course_avg.add(temp);
        101			}
        102			ps.close();
        103			result.close();
        104		} catch (SQLException e) {
        
        105			e.printStackTrace();
        106		} finally {
        
        107			DBUtils.closeConnection(conn);
        108		}
        109		return course_avg;
        110	}
        111	//查询课程不及格率，返回一个ArrayList集合
        112	public ArrayList<Course_fail_rate> fail_rate(){
        
        113		Connection conn = DBUtils.getConnection();
        114		String sql = "select cno,(select cname from course where cno = x.cno) cname,cast(100.0*(select count(sno) from sc where grade < 60 and cno = x.cno)/(select count(sno) from sc where cno = x.cno) as decimal(18,2)) rate from sc x group by cno order by cno;";
        115		ArrayList<Course_fail_rate> fail_rate = new ArrayList<Course_fail_rate>();
        116		try {
        
        117			PreparedStatement ps = (PreparedStatement) conn.prepareStatement(sql);
        118			ResultSet rs = ps.executeQuery();
        119			while(rs.next()){
        
        120				Course_fail_rate temp = new Course_fail_rate();
        121				temp.setCno(rs.getString("cno"));
        122				temp.setCname(rs.getString("cname"));
        123				temp.setFail_rate(rs.getDouble("rate"));
        124				fail_rate.add(temp);
        125			}
        126			rs.close();
        127			ps.close();
        128		} catch (SQLException e) {
        
        129			e.printStackTrace();
        130		} finally {
        
        131			DBUtils.closeConnection(conn);
        132		}
        133		return fail_rate;
        134	}
        135	//查询课程排名情况,返回一个ArrayList集合
        136	public ArrayList<Course_ranking> course_ranking(String cno){
        
        137		Connection conn = DBUtils.getConnection();
        138		String sql = "select student.Sno Sno,Dname,Clname,Sname,Ssex,Sage,Grade from department,class,student,sc where student.sno = sc.sno and class.Clno = student.Clno and department.Dno = class.Dno and cno = '"+cno+"' order by grade desc;";
        139		ArrayList<Course_ranking> course_ranking = new ArrayList<Course_ranking>();
        140		try {
        
        141			PreparedStatement ps = (PreparedStatement) conn.prepareStatement(sql);
        142			ResultSet rs = ps.executeQuery();
        143			while(rs.next()){
        
        144				Course_ranking temp = new Course_ranking();
        145				temp.setSno(rs.getString("Sno"));
        146				temp.setDname(rs.getString("Dname"));
        147				temp.setClname(rs.getString("Clname"));
        148				temp.setSname(rs.getString("Sname"));
        149				temp.setSsex(rs.getString("Ssex"));
        150				temp.setSage(rs.getInt("Sage"));
        151				temp.setGrade(rs.getDouble("Grade"));
        152				course_ranking.add(temp);
        153			}
        154			rs.close();
        155			ps.close();
        156		} catch (SQLException e) {
        
        157			e.printStackTrace();
        158		} finally {
        
        159			DBUtils.closeConnection(conn);
        160		}
        161		return course_ranking;
        162	}
        }

## 项目获取: ##

[https://gitee.com/sinonfin/L-javaWebSha/tree/master][https_gitee.com_sinonfin_L-javaWebSha_tree_master]

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[https_gitee.com_sinonfin_L-javaWebSha_tree_master]: https://gitee.com/sinonfin/L-javaWebSha/tree/master