学生管理系统开发代码分析笔记：jsp+java bean+servlet技术

1 序言

学习java web的时候很渴望有一份完整的项目给我阅读，而网上的大部分项目拿过来都无法直接用，好不容易找到了一个学生管理系统也是漏洞百出。在此，我将边修改边学习这份代码，并且加上完全的注释，以便日后查阅。

2 项目说明

该项目为常见的学生管理系统，系统用例就不再说明。

《待补充》

3 代码分析

1 登录功能

1 首页 index.jsp

 

<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>



  
    
    
    
    
        
    
    
    
  
  
  
    <% response.sendRedirect("user/index.jsp"); %>
    <%--script跳转有的浏览器不识别，比如火狐，应该使用response.sendRedict()方式更为正确，
        之后好多这种情况这种情况，不再一一说明 --%>
  

 

2  user/index.jsp

 

<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>



  
    
    
    
    
	
	
	    
	
	
	

  
  <%--调用js进行前台检查，经常用到的这一段代码，复用率相当高 --%>
  
  
<%--本页面为真正登陆页面,因此会有两种状态,1.登陆成功跳转到下一个页面,2是登陆失败重新登录,因此要接受登陆状态参数"error" --%>
<%
String error = (String)request.getAttribute("error");
if(error != null && error.equals("1")){
%><%
}
 %>
  <%--将表单提交到servlet/user/UserLoginServlet中 --%>
    

    

    
inxi　
	
　
	
　
    

		

			
研究生工程实践管理系统

		
		

			
用 户 名：
			

		
		

			
登录密码：
			

		
		

			
请选择登录身份：
			

			
			研究生
			企业导师
			
			
		
		

			
    
		
	
    
    
   

 

3 UserLonginBean

这个工程中的Bean总共四个，用到的时候陆续贴出来

 

package bean;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.*;
import util.*;

public class UserLoginBean {
    Connection conn = null;
    Statement st = null;
    ResultSet rs = null;
    ArrayList al = new ArrayList();//容器的方式来接受出巡出来的结果，每个对象是查询结果的每一列，这里都是String对象
    
    public int login(String name,String pwd,String station){//返回值int,代表查询状态,这里也可以自定义异常处理,复用率更高
        int temp = 0;
        conn = DBConn.getConn();//util类bean 这里就不贴了，只有get和close的功能
        try {
            st = conn.createStatement();
            if(station.equals("学生")){//若身份为学生，则查询学生表，若是老师查询老师表
                rs = st.executeQuery("select * from student where name='"+name+"'");
            }
            if(station.equals("指导老师")){//老师分为指导老师和其他老师，这里只查询指导老师，功能待扩充
                rs = st.executeQuery("select * from teacher where name='"+name+"' and station='"+station+"'");
            }
        
            if(rs.next()){//若查询到有结果,则证明有该用户
                String id = rs.getString("id");
                String tname = rs.getString("name");
                String tpwd = rs.getString("pwd");
                String truename = rs.getString("truename");
                String stations = rs.getString("station");
                if(pwd.equals(tpwd)){//取出密码字段匹配,匹配成功取出信息,放入容器
                    temp = 1;//1状态代表查询成功
                    al.add(id);
                    al.add(tname);
                    al.add(tpwd);
                    al.add(stations);
                    al.add(truename);
                }else{
                    temp = 2;//2 代表密码不匹配
                }
            }else{
                temp = 3;//3代表没有该用户名
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally{
            DBConn.close(conn,st,rs);//最后关闭打开的对象,利用bean关闭
        }
        return temp;//返回登录状态
    }
    
    public ArrayList getArrayLst(){
        return al;//返回登录查询到的结果
    }

}

 

4  servlet/user/UserLoginServlet

 

package servlet.user;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import util.Validate;
import bean.UserLoginBean;

public class UserLoginServlet extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public UserLoginServlet() {
		super();
	}

	/**
	 * Destruction of the servlet. 

	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}
//由于表单是post过来的，这里要将post转到get
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		Validate vd = new Validate();//字符转换类，不再贴了
		String name = vd.getUnicode(request.getParameter("name"));
		String pwd = vd.getUnicode(request.getParameter("pwd"));
		String station = vd.getUnicode(request.getParameter("station"));
		UserLoginBean lb = new UserLoginBean();//创建UserLoginBean对象,所有的用户操作都用得上,所以封装为Bean
		int flag = lb.login(name,pwd,station);//将表单传递过来的参数登录
		ArrayList al = lb.getArrayLst();//获取登录结果,若没有登录成功则为null
		HttpSession session = request.getSession();
		session.setAttribute("login", al);//创建session,将login设为登录成功的返回容器
		String str = "";
		if(flag == 2 || flag == 3){//2 3都代表登录失败
			str = "/user/index.jsp";
			request.setAttribute("error", "1");//设置error为登录失败状态
		}else{
			if(al.get(3).equals("学生"))//若是学生返回,转发至/user/student_list_3.jsp,老师则/user/student_list_2.jsp
			    str = "/user/student_list_3.jsp";
			else str = "/user/student_list_2.jsp";
		}
		RequestDispatcher rd=request.getRequestDispatcher(str);
        rd.forward(request,response);
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request,response);
	}

	/**
	 * Initialization of the servlet. 

	 *
	 * @throws ServletException if an error occure
	 */
	public void init() throws ServletException {
		// Put your code here
	}

}

至此,登陆功能已经完成,接下来是选课功能

 

2 选课功能

1 SelectBean

 

package bean;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import util.DBConn;

public class SelectBean {
	
	Connection conn = null;
	Statement st = null;
	ResultSet rs = null;
	
	public ArrayList select(String sql,String[] args){
		ArrayList al = new ArrayList();
		conn = DBConn.getConn();
		try {
			st = conn.createStatement();
			rs = st.executeQuery(sql);
			while(rs.next()){
				ArrayList alRow = new ArrayList();
				for(int i = 0;i < args.length;i++){
					alRow.add(rs.getString(args[i]));
				}
				al.add(alRow);//按语句查询后,依次将查询到的结果装入容器
			}
		} catch (SQLException e) {
			// TODO 自动生成 catch 块
			e.printStackTrace();
		} finally{
			DBConn.close(conn,st,rs);
		}
		return al;//返回查询结果容器
	}

}

 

2 ListServlet

将需要列出来的结果都查询出来先

 

package servlet;

import java.io.IOException;
import java.util.ArrayList;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import util.Validate;

import bean.SelectBean;

public class ListServlet extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public ListServlet() {
		super();
	}

	/**
	 * Destruction of the servlet. 

	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		SelectBean sb = new SelectBean();
		
		String sql1 = "select * from teacher where station='指导老师'";
		String[] args1 = {"id","name","pwd","truename","sex","age","phone","addr","station"};
		ArrayList al1 = sb.select(sql1, args1);
		request.setAttribute("tutor", al1);//将指导老师查询结果装入al1
		
		String sql2 = "select * from teacher where station='指导班主任'";
		String[] args2 = {"id","name","pwd","truename","sex","age","phone","addr","station"};
		ArrayList al2 = sb.select(sql2, args2);
		request.setAttribute("mostly", al2);//将班主任查询结果装入al2
		
		String sql3 = "select * from projectbase";
		String[] args3 = {"baseid","basename","contacts","baseaddress","basephone","baseemail","baseintroduction"};
		ArrayList al3 = sb.select(sql3, args3);
		request.setAttribute("captain", al3);//将项目信息装入al3
		
	
		
		String sql4 = "select * from school";
		String[] args4 = {"id","name","pwd","truename","addr","station"};
		ArrayList al4 = sb.select(sql4, args4);
		request.setAttribute("school", al4);//将学校信息装入al4
		
		String sql5 = "select * from student";
		String[] args5 = {"id","name","pwd","truename","sex","age","phone","addr","station"};
		ArrayList al5 = sb.select(sql5, args5);
		request.setAttribute("student", al5);//将学生信息装入al5
		
		String sql11 = "select * from project,projectbase where project.baseid = projectbase.baseid";
        String[] args11 = {"projectid","projectname","basename","projectinfo","state"};
        ArrayList al11 = sb.select(sql11, args11);
        request.setAttribute("project", al11);//关联两表,查询学生申请的项目信息,装入al11
		
		String sql6 = "select * from course";
		String[] args6 = {"id","name","times","student"};
		ArrayList al6 = sb.select(sql6, args6);
		request.setAttribute("course", al6);//成绩信息装入al6
		
		Validate vd = new Validate();
        String baseid = vd.getUnicode(request.getParameter("baseid"));
		String sql7 = "select * from project where baseid="+baseid;
		String[] args7 = {"projectid","projectname","baseid","projectinfo","state"};
		ArrayList al7 = sb.select(sql7, args7);
		request.setAttribute("studentleave", al7);//根据传递过来的参数,查找学生申请情况,装入al7
		

        String sql12 = "select * from resource where baseid="+baseid;
        String[] args12 = {"resourcename","resourcenumber","resourceinfor","resourcestate","baseid","teacherid","resourceid"};
        ArrayList al12 = sb.select(sql12, args12);
        request.setAttribute("resources", al12);//根据传递过来的参数,查询与项目相关的指定项目的资源信息,转入al12
       
/*		
		HttpSession session = request.getSession();
		ArrayList adminlogin = (ArrayList)session.getAttribute("adminlogin");
		if(!adminlogin.get(3).equals(1))
	{
		ArrayList login = (ArrayList)session.getAttribute("login");
		String sql12 = "select project.projectid,projectname,projectinfo,teacherproject.state from teacherproject,project,teacher where project.projectid = teacherproject.projectid and teacherproject.id=teacher.id and teacherproject.id="+login.get(0);
        String[] args12 = {"projectid","projectname","projectinfo","state"};
        ArrayList al12 = sb.select(sql12, args12);
        request.setAttribute("teacherlookapply", al12);

//		HttpSession session = request.getSession();
        ArrayList login1 = (ArrayList)session.getAttribute("login");
        String sql13 = "select project.projectid,projectname,projectinfo,studentproject.state from studentproject,project,student where project.projectid = studentproject.projectid and studentproject.id=student.id and studentproject.id="+login1.get(0);
        String[] args13 = {"projectid","projectname","projectinfo","state"};
        ArrayList al13 = sb.select(sql13, args13);
        request.setAttribute("studentlookapply", al13);
	}
*/
		
		String sql8 = "select * from teacherleave";
		String[] args8 = {"id","teacherid","teacher","title","content","times"};
		ArrayList al8 = sb.select(sql8, args8);
		request.setAttribute("teacherleave", al8);//查询老师留言,装入al8
		
		String sql9 = "select * from grade";
		String[] args9 = {"id","studentd","coursety","gradentn"};
		ArrayList al9 = sb.select(sql9, args9);
		request.setAttribute("grade", al9);//查询年级信息装入al9
		
		String sql10 = "select * from taste";
		String[] args10 = {"id","student","title","content","times"};
		ArrayList al10 = sb.select(sql10, args10);
		request.setAttribute("taste", al10);//查询学生留言
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request,response);
	}

	/**
	 * Initialization of the servlet. 

	 *
	 * @throws ServletException if an error occure
	 */
	public void init() throws ServletException {
		// Put your code here
	}

}

 

3 SessLoginServlet

检查session,检查是否登陆成功

 

package servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class SessLoginServlet extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public SessLoginServlet() {
		super();
	}

	/**
	 * Destruction of the servlet. 

	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		PrintWriter pw = response.getWriter();
		if(request.getSession().getAttribute("login") == null || request.getSession().getAttribute("login").equals("")){
			pw.write("");
		}
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request,response);
	}

	/**
	 * Initialization of the servlet. 

	 *
	 * @throws ServletException if an error occure
	 */
	public void init() throws ServletException {
		// Put your code here
	}

}

 

3 user/top.jsp

页面的抬头分离写出来,别的页面时用include指令包含进来

 

<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>



  
    
    
    
    
	
	
	    
	
	
	
	
	

  
  
  	
  
	

	

	

		研究生工程实践管理系统
  

  

  

  

  
<%-- 
  
--%> 

  
  <%//检查login是否登陆成功,显示教学资源管理链接
  if(request.getSession().getAttribute("login") != null && !request.getSession().getAttribute("login").equals("")){
  	ArrayList al = (ArrayList)session.getAttribute("login");
	  if(al.get(3).equals("指导老师")){	  
	%><%
  }}
   %>
<%--   --%>
  
 <%--  --%>
  

  
课程安排|
  
学生留言|
  
老师留言|
 
  
学生成绩发布|
工程实践项目管理|
实践教学资源管理|
实践教学资源管理|
个人信息管理|
  
修改密码|
个人信息管理|
注销退出
 
  
  
  
  
  
  
  
  	
  

4 StudentSelectServlet

 

package servlet.user;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import bean.SelectBean;

import util.Validate;

public class StudentSelectServlet_1 extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public StudentSelectServlet_1() {
		super();
	}

	/**
	 * Destruction of the servlet. 

	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		Validate vd = new Validate();
		String projectname = vd.getUnicode(request.getParameter("projectname_1"));
		SelectBean sb = new SelectBean();
		String sql = "select * from project,projectbase ";
		String[] args = {"projectid","projectname","basename","projectinfo","state"};
		sql += "where project.baseid = projectbase.baseid and projectname like '%"+projectname+"%'";
		ArrayList al = sb.select(sql, args);
		request.setAttribute("students", al);
		RequestDispatcher rd=request.getRequestDispatcher("/user/student_list_3.jsp");
		rd.forward(request,response);
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request,response);
	}

	/**
	 * Initialization of the servlet. 

	 *
	 * @throws ServletException if an error occure
	 */
	public void init() throws ServletException {
		// Put your code here
	}

}

 

 

 

转载于:https://www.cnblogs.com/kingszelda/p/7142699.html