基于web的学生管理系统（二）java代码阶段

本文主要是介绍基于web的学生管理系统（二）java代码阶段，对大家解决编程问题具有一定的参考价值，需要的程序猿们随着小编来一起学习吧！

代码实现

（一）dao包下代码

1、BaseDao

package com.offcn.dao;

import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;

import java.sql.SQLException;
import java.util.List;

public class BaseDao<T> {
    static ComboPooledDataSource ds = null;
    static QueryRunner qr = null;
    static{
        ds = new ComboPooledDataSource();//创建c3p0的连接池对象
        qr = new QueryRunner(ds);
    }
    //封装增删改方法
    public int update(String sql,Object...params){
        try {
            return qr.update(sql,params);
        } catch (SQLException e) {
            e.printStackTrace();
            throw new RuntimeException();
        }
    }
    //单行查询
    public  T queryOne(String sql,Class<T> clazz,Object... params){
        try {
            return qr.query(sql,new BeanHandler<>(clazz),params);
        } catch (SQLException e) {
            e.printStackTrace();
            throw new RuntimeException();
        }
    }
    //多行查询
    public List<T> queryMore(String sql, Class<T> clazz, Object...params){
        try {
            return qr.query(sql,new BeanListHandler<>(clazz),params);
        } catch (SQLException e) {
            e.printStackTrace();
            throw new RuntimeException();
        }
    }
    //聚合查询
    public Number queryScar(String sql,Object...params){
        try {
            return qr.query(sql,new ScalarHandler<Number>(),params);
        } catch (SQLException e) {
            e.printStackTrace();
            throw new RuntimeException();
        }
    }

}

2、StudentDao

package com.offcn.dao;

import com.offcn.entity.Page;
import com.offcn.entity.Student;

import java.util.List;

public class StudentDao extends BaseDao<Student> {
    //删除学生信息
    public boolean delete(int id){
        String sql = "delete from stu where sid=?";
        return update(sql,id)>0 ? true : false;
    }

    //添加学生信息
    public boolean insert(Student s){
        String sql = "insert into stu(name,age,tel,bir,sex,spic)values(?,?,?,?,?,?)";
        Object[] param={s.getName(),s.getAge(),s.getTel(),s.getBir(),s.getSex(),s.getSpic()};
        return update(sql,param)>0 ? true : false;
    }

    //根据id查询学生信息
    public Student stuSinSer(int id){
        String sql = "select * from stu where sid=?";
        return queryOne(sql,Student.class,id);
    }

    //修改学生信息
    public boolean updateStu(Student s,int id){
        String sql = "update stu set name=?,age=?,tel=?,bir=?,sex=?,spic=?where sid=?";
        Object[] param={s.getName(),s.getAge(),s.getTel(),s.getBir(),s.getSex(),s.getSpic(),id};
        return update(sql,param)>0 ? true : false;
    }

    //模糊查询
    public List<Student> StuLike(String name,String sex,Page p){
        StringBuffer sql = new StringBuffer("select * from stu where 1=1");
        if(name!=null&&!"".equals(name)){
            sql.append(" and name like '%"+name+"%'");
        }
        if("0".equals(sex)||"1".equals(sex)){
            sql.append(" and sex="+sex);
        }
        sql.append(" limit ?,?");
        return queryMore(sql.toString(),Student.class,p.getStartIndex(),p.getPageSize());
    }

    public int LikeNum(String name,String sex){
        StringBuffer sql = new StringBuffer("select count(*) from stu where 1=1");
        if(name!=null&&!"".equals(name)){
            sql.append(" and name like '%"+name+"%'");
        }
        if("0".equals(sex)||"1".equals(sex)){
            sql.append(" and sex="+sex);
        }
        return queryScar(sql.toString()).intValue();
    }

}

3、UserDao

package com.offcn.dao;

import com.offcn.entity.User;

public class UserDao extends BaseDao<User> {
    //根据用户名和密码查询用户信息
    public User login(String username,String password){
        String sql = "select * from user where username=? and pwd=?";
        return queryOne(sql,User.class,username,password);
    }
    //添加用户信息
    public Boolean register(User u){
        String sql = "insert into user(username,pwd,name,tel,bir) values(?,?,?,?,?)";
        Object[] param = {u.getUsername(),u.getPwd(),u.getName(),u.getTel(),u.getBir()};
        return update(sql,param)>0 ? true : false;
    }
}

（二）entity包下代码

1.Student类

package com.offcn.entity;

import java.util.Date;

public class Student {
    private int sid;
    private String name;
    private int age;
    private String tel;
    private Date bir;
    private int sex;
    private String spic;

    public Student() {
    }

    public Student(String name, int age, String tel, Date bir, int sex, String spic) {

        this.name = name;
        this.age = age;
        this.tel = tel;
        this.bir = bir;
        this.sex = sex;
        this.spic = spic;
    }

    public String getSpic() {
        return spic;
    }

    public void setSpic(String spic) {
        this.spic = spic;
    }

    public int getSid() {
        return sid;
    }

    public void setSid(int sid) {
        this.sid = sid;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getTel() {
        return tel;
    }

    public void setTel(String tel) {
        this.tel = tel;
    }

    public Date getBir() {
        return bir;
    }

    public void setBir(Date bir) {
        this.bir = bir;
    }

    public int getSex() {
        return sex;
    }

    public void setSex(int sex) {
        this.sex = sex;
    }
}

2、User类

package com.offcn.entity;

import java.util.Date;

public class User {
    private String username;
    private String pwd;
    private String name;
    private String tel;
    private Date bir;

    public User() {
    }

    public User(String username, String pwd, String name, String tel, Date bir) {
        this.username = username;
        this.pwd = pwd;
        this.name = name;
        this.tel = tel;
        this.bir = bir;
    }

    @Override
    public String toString() {
        return "User{" +
                "username='" + username + '\'' +
                ", pwd='" + pwd + '\'' +
                ", name='" + name + '\'' +
                ", tel='" + tel + '\'' +
                ", bir=" + bir +
                '}';
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getTel() {
        return tel;
    }

    public void setTel(String tel) {
        this.tel = tel;
    }

    public Date getBir() {
        return bir;
    }

    public void setBir(Date bir) {
        this.bir = bir;
    }
}

3、Page类

package com.offcn.entity;

public class Page {
    private int curPage;//当前页
    private int pageSize;//页容量
    private int nextPage;//下一页
    private int prevPage;//上一页
    private int rows;//总记录数
    private int endPage;//总页数
    private int startIndex;//每一页的起始行下标
    //总体初始化
    public Page(int rows,String curPage) {
        this.rows = rows;
        this.pageSize=5;
        initCurPage(curPage);
        initPrevPage();
        initEndPage();
        initNextPage();
        initStartIndex();

    }
    //属性初始化
    //初始化当前页
    public void initCurPage(String curPage){
        //当页面不传当前页，或当前页为空字符串默认首页
        if(curPage==null||"".equals(curPage)){
            this.curPage = 1;
        }else {
            this.curPage=Integer.valueOf(curPage);
        }
    }
    //初始化上一页
    public void initPrevPage(){
        if(curPage>1){
            prevPage=curPage-1;
        }else {
            prevPage=1;
        }
    }
    //初始化下一页
    public void initNextPage(){
        if(curPage<endPage){
            nextPage=curPage+1;
        }else {
            nextPage=endPage;
        }
    }
    //初始化总页数
    public void initEndPage(){
        if(rows%pageSize==0){
            endPage=rows/pageSize;
        }else {
            endPage=rows/pageSize+1;
        }
    }
    //初始化起始行
    public void initStartIndex(){
        startIndex=(curPage-1)*pageSize;
    }

    public int getCurPage() {
        return curPage;
    }

    public void setCurPage(int curPage) {
        this.curPage = curPage;
    }

    public int getPageSize() {
        return pageSize;
    }

    public void setPageSize(int pageSize) {
        this.pageSize = pageSize;
    }

    public int getNextPage() {
        return nextPage;
    }

    public void setNextPage(int nextPage) {
        this.nextPage = nextPage;
    }

    public int getPrevPage() {
        return prevPage;
    }

    public void setPrevPage(int prevPage) {
        this.prevPage = prevPage;
    }

    public int getRows() {
        return rows;
    }

    public void setRows(int rows) {
        this.rows = rows;
    }

    public int getEndPage() {
        return endPage;
    }

    public void setEndPage(int endPage) {
        this.endPage = endPage;
    }

    public int getStartIndex() {
        return startIndex;
    }

    public void setStartIndex(int startIndex) {
        this.startIndex = startIndex;
    }
}

（三）filter包下代码

1、EncodeFilter类

package com.offcn.filter;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;
//Filter过滤器，解决乱码
@WebFilter("/*")
public class EncodeFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        servletRequest.setCharacterEncoding("utf-8");
        servletResponse.setContentType("text/html;charset=utf-8");
        filterChain.doFilter(servletRequest,servletResponse);
    }
}

2、LoginFilter类

package com.offcn.filter;

import com.offcn.entity.User;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
//登录过滤器
@WebFilter("/*")
public class LoginFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        //向下转型
        HttpServletRequest req = (HttpServletRequest)servletRequest;
        HttpServletResponse resp = (HttpServletResponse)servletResponse;
        //获取uri地址
        String uri = req.getRequestURI();
        //截取出需要的地址
        String uriPath = uri.substring(uri.lastIndexOf("/")+1);
        //判断，所有登录之前的操作直接放行，否则查看是否有用户信息，有就直接放行，没有就回到登录页面去登录
        if("register.jsp".equals(uriPath)||"register".equals(uriPath)||"hello".equals(uriPath)||"index.jsp".equals(uriPath)){
            filterChain.doFilter(req,resp);
        }else {
            HttpSession session = req.getSession();
            Object user = (User)session.getAttribute("user");
            if(user!=null){
                filterChain.doFilter(req,resp);
            }else{
                resp.sendRedirect("index.jsp");
            }
        }
    }
}

（四）login包下代码

1、Login类

package com.offcn.login;

import com.offcn.dao.UserDao;
import com.offcn.entity.User;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.IOException;
@WebServlet("/hello")
public class Login extends HttpServlet{
    //实例化dao对象
    UserDao ud = new UserDao();
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //从网页上获取用户名和用户密码
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        //获取记住密码的勾选状态
        String save = req.getParameter("save");
        //调用userdao的登录方法，用一个User对象接收
        User us = ud.login(username,password);
        //判断us是否有值，有值，则用户存在切密码正确，进行登录操作，没值则进入登录失败页面
        if(us != null){
            //如果记住密码勾选，则进行记住密码操作
            if("checkon".equals(save)){
                //创建Cookie对象，将用户输入的用户名和密码存入Cookie
                //实现记住密码功能
                Cookie c1 = new Cookie("username",us.getUsername());
                Cookie c2 = new Cookie("password",us.getPwd());
                //给Cookie设置过期时间
                c1.setMaxAge(60*60*24*7);
                c2.setMaxAge(60*60*24*7);
                //将Cookie响应到浏览器
                resp.addCookie(c1);
                resp.addCookie(c2);
            }
            //实现用户跟踪校验功能，没有登录没法进入其他页面
            //创建session，将us对象绑定到session
            HttpSession session = req.getSession();
            session.setAttribute("user",us);
            //登录之后转发到主页面
            req.getRequestDispatcher("student").forward(req,resp);
        }else {
            //登录失败进入登录失败页面
            resp.sendRedirect("login_fail.jsp");
        }
    }
}

2、LoginOut类

package com.offcn.login;

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 javax.servlet.http.HttpSession;
import java.io.IOException;
@WebServlet("/logout")
public class LogOut extends HttpServlet {
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        HttpSession session = req.getSession();
        session.invalidate();
        resp.sendRedirect("index.jsp");
    }
}

3、Register类

package com.offcn.login;

import com.offcn.dao.UserDao;
import com.offcn.entity.User;

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 java.io.IOException;
//注册
@WebServlet("/register")
public class Register extends HttpServlet {
    UserDao ud = new UserDao();
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获取信息
        String username = req.getParameter("username");
        String pwd = req.getParameter("pwd");
        String name = req.getParameter("name");
        String tel = req.getParameter("tel");
        String bir = req.getParameter("bir");
        //存入数据库
        User u = new User(username,pwd,name,tel,DateUtil.dateformat(bir));
        boolean b = ud.register(u);
        if(b){
            resp.sendRedirect("index.jsp");
        }else {
            resp.sendRedirect("register.jsp");
        }

    }
}

4、InsertServlet类

package com.offcn.login;

import com.offcn.dao.StudentDao;
import com.offcn.entity.Student;

import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;
import java.io.File;
import java.io.IOException;
import java.util.UUID;
//插入学生信息操作
@MultipartConfig
@WebServlet("/insert")
public class InsertServlet extends HttpServlet {
    //实例化StudentDao
    StudentDao sd = new StudentDao();
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获取页面中输入的学生信息
        String name = req.getParameter("name");
        String age = req.getParameter("age");
        String tel = req.getParameter("tel");
        String bir = req.getParameter("bir");
        String sex = req.getParameter("sex");
        Part part = req.getPart("spic");
        //获取图片信息的名字
        String filename = part.getSubmittedFileName();
        //给图片重新命名
        filename = UUID.randomUUID()+filename;
        //图片的保存路径
        String path = "d:/pic";
        //实例化Student，并将获取的学生信息传入
        Student student = new Student(name,Integer.parseInt(age),tel,DateUtil.dateformat(bir),Integer.parseInt(sex),filename);
        //调用插入学生信息方法，将信息传入数据库
        boolean b = sd.insert(student);
        if(b){
            //如果插入成功，则创建文件夹存储图片，并跳转回主页面
            File f = new File(path);
            if(!f.exists()){
                f.mkdir();
            }
            part.write(path+File.separator+filename);
            resp.sendRedirect("student");
        }
    }
}

5、DeleteServlet类

package com.offcn.login;

import com.offcn.dao.StudentDao;

import javax.servlet.ServletContext;
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 java.io.IOException;

//删除操作的servlet
@WebServlet("/delete")
public class deleteServlet extends HttpServlet {
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获取要删除学生的id
        int id = Integer.parseInt(req.getParameter("id"));
        //实例化StudentDao
        StudentDao sd = new StudentDao();
        //调用删除学生信息方法
        boolean b = sd.delete(id);
        //删除之后跳转回主页面
        resp.sendRedirect("student");
    }
}

6、StuServlet类

package com.offcn.login;

import com.offcn.dao.StudentDao;
import com.offcn.entity.Page;
import com.offcn.entity.Student;

import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;
@MultipartConfig
@WebServlet("/student")
public class StuServlet extends HttpServlet {
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String curPage = req.getParameter("curPage");
        String name = req.getParameter("name");
        String sex = req.getParameter("sex");
        StudentDao sd = new StudentDao();
        int rows = sd.LikeNum(name,sex);
        Page p = new Page(rows,curPage);
        List<Student> list = sd.StuLike(name,sex,p);
        req.setAttribute("list",list);
        req.setAttribute("p",p);
        req.setAttribute("name",name);
        req.setAttribute("sex",sex);
        req.getRequestDispatcher("stuservlet.jsp").forward(req,resp);
    }
}

7、UpdateServlet类

package com.offcn.login;

import com.offcn.dao.StudentDao;
import com.offcn.entity.Student;

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

@WebServlet("/update")
public class UpdateServlet extends HttpServlet {
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String id = req.getParameter("id");
        StudentDao sd = new StudentDao();
        Student s1 = sd.stuSinSer(Integer.parseInt(id));
        req.setAttribute("s1",s1);
        req.getRequestDispatcher("/update.jsp").forward(req,resp);
    }
}

8、Update2类

package com.offcn.login;

import com.offcn.dao.StudentDao;
import com.offcn.entity.Student;

import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.UUID;
@MultipartConfig
@WebServlet("/update2")
public class Update2 extends HttpServlet {
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        StudentDao sd = new StudentDao();
        String id = req.getParameter("id");
        String name = req.getParameter("name");
        String age = req.getParameter("age");
        String tel = req.getParameter("tel");
        String bir = req.getParameter("bir");
        String sex = req.getParameter("sex");
        String spic = req.getParameter("spic");
        Part part = req.getPart("newspic");
        String path = "d:/pic";
        String filename = part.getSubmittedFileName();
        String pic = spic;
        if(!"".equals(filename)){
            filename= UUID.randomUUID()+filename;
            pic = filename;
            part.write(path+File.separator+pic);
            File f = new File(path+File.separator+spic);
            f.delete();
        }

        Student s2 = new Student(name,Integer.parseInt(age),tel,DateUtil.dateformat(bir),Integer.parseInt(sex),pic);
        boolean b = sd.updateStu(s2,Integer.parseInt(id));
        if(b){
            resp.sendRedirect("student");
        }
    }
}

9、DateUtils类

package com.offcn.login;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
//日期工具类
//做字符串转日期，日期转字符串的操作
public class DateUtil {
    //将字符串转为日期类型
    public static Date dateformat(String s){
        SimpleDateFormat sdf = new SimpleDateFormat("YY-MM-dd");
        try {
            return sdf.parse(s);
        } catch (ParseException e) {
            e.printStackTrace();
            throw new RuntimeException();
        }

    }
    //将日期类型转为字符串
    public static String format(Date d){
        SimpleDateFormat sdf = new SimpleDateFormat("YY-MM-dd");
        try {
            return sdf.format(d);
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException();
        }

    }

}

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Java教程

基于web的学生管理系统（二）java代码阶段

代码实现

（一）dao包下代码

1、BaseDao

2、StudentDao

3、UserDao

（二）entity包下代码

1.Student类

2、User类

3、Page类

（三）filter包下代码

1、EncodeFilter类

2、LoginFilter类

（四）login包下代码

1、Login类

2、LoginOut类

3、Register类

4、InsertServlet类

5、DeleteServlet类

6、StuServlet类

7、UpdateServlet类

8、Update2类

9、DateUtils类

前端开发

后端开发

移动端开发

数据库

服务器运维

人工智能

区块链

游戏开发

网站运营

大数据/云计算

软件工程

软件/开发工具使用

资讯