java操作数据库，以页面显示学生信息为例

# 数据库 2024-05-05 22:58 0 140 来源： 云博客 
该部分内容实现的功能主要是：从数据库中查询数据并展示到页面，在页面中新增数据信息，在页面中修改数据信息，在页面中删除数据信息。=================stuList.jsp================//本页为数据显示页面<%@ page import="java.util.List" %><%@ page import="com.ibeifeng.student.Student" %><%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head> <title>stuList</title></head><body><a href="addStu.jsp">新增学员</a><table width="100%" border="1px solid black"> <tr> <td>学号</td> <td>姓名</td> <td>密码</td> <td>性别</td> <td>邮箱</td> <td>操作</td> </tr> <% List<Student> list = (List<Student>)request.getAttribute("list"); for(Student stu : list){ %> <tr> <td><%=stu.getId()%></td> <td><%=stu.getName()%></td> <td><%=stu.getPwd()%></td> <td><%=stu.getSex()%></td> <td><%=stu.getEmail()%></td> <td><a href="updateStu.jsp?sid=<%=stu.getId()%>">修改</a> | <a href="doDel.jsp?sid=<%=stu.getId()%>">删除</a></td> </tr> <% } %></table></body></html>===============doList02.jsp==================//本页是数据显示页面stuList的后台数据处理部分<%@ page contentType="text/html;charset=UTF-8" language="java" %><%@ page import="java.sql.DriverManager" %><%@ page import="java.sql.Connection" %><%@ page import="java.sql.PreparedStatement" %><%@ page import="java.sql.ResultSet" %><%@ page import="com.ibeifeng.student.Student" %><%@ page import="java.util.ArrayList" %><%@ page import="java.util.List" %><%@ page import="com.ibeifeng.student.ConfigUtil" %><%@ page contentType="text/html;charset=UTF-8" language="java" %><% Class.forName(new ConfigUtil().getValue("driver")); Connection conn = DriverManager.getConnection( new ConfigUtil().getValue("url"), new ConfigUtil().getValue("username"), new ConfigUtil().getValue("password")); String sql = "select * from student"; PreparedStatement ps = conn.prepareStatement(sql); ResultSet rs = ps.executeQuery(); List<Student> list = new ArrayList<Student>(); while(rs.next()){ Student stu = new Student(); stu.setId(rs.getInt(1)); stu.setName(rs.getString(3)); stu.setPwd(rs.getString(2)); stu.setSex(rs.getInt(4)); stu.setEmail(rs.getString(5)); list.add(stu); } if(rs != null){ rs.close(); } if(ps != null){ ps.close(); } if(conn != null){ conn.close(); } request.setAttribute("list",list); request.getRequestDispatcher("stuList.jsp").forward(request,response);%>====================addStu.jsp==============//本页为新增数据的页面展示部分<%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head> <title>新增学员信息</title></head><body><form action="doSave.jsp" method="post"> <table align="center" border="1px solid black"> <tr> <td>学号</td> <td><input type="text" name="stuId" > </td> </tr> <tr> <td>姓名</td> <td><input type="text" name="stuName" ></td> </tr> <tr> <td>密码</td> <td><input type="password" name="pwd" ></td> </tr> <tr> <td>性别</td> <td> <input type="radio" name="gender" value="0">女 <input type="radio" name="gender" value="1">男 </td> </tr> <tr> <td>邮箱</td> <td><input type="text" name="email" ></td> </tr> <tr> <td colspan="2"> <input type="submit" name="submit" value="保存"> <input type="button" name="return" value="取消"> </td> </tr> </table></form></body></html>===================doSave.jsp==============//本页为数据新增页面，保存按钮的数据处理部分<%@ page import="com.ibeifeng.student.ConfigUtil" %><%@ page import="java.sql.DriverManager" %><%@ page import="java.sql.Connection" %><%@ page import="java.sql.PreparedStatement" %><%@ page import="java.sql.ResultSet" %><%@ page contentType="text/html;charset=UTF-8" language="java" %><% request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); Class.forName(new ConfigUtil().getValue("driver")); Connection conn = DriverManager.getConnection( new ConfigUtil().getValue("url"),new ConfigUtil().getValue("username"),new ConfigUtil().getValue("password")); String sql = "insert into student(stu_id,stu_name,pwd,sex,email) values(?,?,?,?,?)"; PreparedStatement ps = conn.prepareStatement(sql); String rid = request.getParameter("stuId"); int id = Integer.parseInt(rid); ps.setInt(1,id); ps.setString(2,request.getParameter("stuName")); ps.setString(3,request.getParameter("pwd")); ps.setInt(4,1); ps.setString(5,request.getParameter("email")); int isSuccess = ps.executeUpdate(); System.out.print(isSuccess); if(isSuccess <= 0){ System.out.print("新增有误，请重试"); request.getRequestDispatcher("/stuInfo/addStu.jsp").forward(request,response); }else{ request.getRequestDispatcher("/stuInfo/doList02.jsp").forward(request,response); } if(ps != null){ ps.close(); } if(conn != null){ conn.close(); }%>================updateStu.jsp===============//本页为数据修改页面展示部分<%@ page import="com.ibeifeng.student.StudentDao" %><%@ page import="com.ibeifeng.student.Student" %><%@ page contentType="text/html;charset=UTF-8" language="java" %><% request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); //获取前端页面传递的参数 String sid = request.getParameter("sid"); //该参数由stuList页面的<a href="updateStu.jsp?sid=stu.getStudentId()">传递过来 //创建StudentDao对象 StudentDao stuDao = new StudentDao(); Student stu = stuDao.getStuByStuId(sid); if(stu != null){ request.setAttribute("stu",stu); }%><html><head> <title>新增学员信息</title></head><body><form action="doUpdate.jsp" method="post"> <table align="center" border="1px solid black"> <tr> <td>学号</td> <td><input type="text" name="stuId" readonly="readonly" value="<%=stu.getId()%>"> </td> </tr> <tr> <td>姓名</td> <td><input type="text" name="stuName" value="<%=stu.getName()%>"></td> </tr> <tr> <td>密码</td> <td><input type="password" name="pwd" value="<%=stu.getPwd()%>"></td> </tr> <tr> <td>性别</td> <td> <input type="radio" name="gender" value="0" <%if(stu.getSex() == 0){%>checked="checked"<%}%>>女 <input type="radio" name="gender" value="1" <%if(stu.getSex() == 1){%>checked="checked"<%}%>>男 </td> </tr> <tr> <td>邮箱</td> <td><input type="text" name="email" value="<%=stu.getEmail()%>"></td> </tr> <tr> <td colspan="2"> <input type="submit" name="submit" value="保存"> <input type="button" name="return" value="取消"> </td> </tr> </table></form></body></html>=================doUpdate.jsp==============//本页为数据修改部分，后台数据处理操作的内容<%@ page import="com.ibeifeng.student.ConfigUtil" %><%@ page import="java.sql.DriverManager" %><%@ page import="java.sql.Connection" %><%@ page import="com.ibeifeng.student.StudentDao" %><%@ page import="com.ibeifeng.student.Student" %><%@ page contentType="text/html;charset=UTF-8" language="java" %><% request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); Class.forName(new ConfigUtil().getValue("driver")); Connection conn = DriverManager.getConnection( new ConfigUtil().getValue("url"),new ConfigUtil().getValue("username"),new ConfigUtil().getValue("password")); String stuid = request.getParameter("stuId"); int sid = Integer.parseInt(stuid); String name = request.getParameter("stuName"); String pwd = request.getParameter("pwd"); String gender = request.getParameter("gender"); int gen = Integer.parseInt(gender); String email = request.getParameter("email"); StudentDao stuDao = new StudentDao(); Student stu = new Student(); stu.setId(sid); stu.setName(name); stu.setPwd(pwd); stu.setSex(gen); stu.setEmail(email); int resule = stuDao.updateStu(stu); if(resule > 0){ request.getRequestDispatcher("doList02.jsp").forward(request,response); }else{ request.getRequestDispatcher("updateStu.jsp?sno="+stuid).forward(request,response); }%>===============doDel.jsp===================//本页为数据删除部分后台处理内容<%@ page import="com.ibeifeng.student.StudentDao" %><%@ page contentType="text/html;charset=UTF-8" language="java" %><% request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); String sid = request.getParameter("sid"); StudentDao stuDao = new StudentDao(); stuDao.delStu(sid); request.getRequestDispatcher("doList02.jsp").forward(request,response);%>===============BaseDao.java=================//本页为封装的方法，主要是涉及到数据库连接的初始化、查询、更新、资源释放package com.ibeifeng.student;import java.sql.*;/** JDBC操作DAO通用类方法封装* */public class BaseDao { static Connection conn = null; static PreparedStatement ps = null; static ResultSet rs = null; //静态语句块 static{ try { Class.forName(ConfigUtil.getValue("driver")); } catch (ClassNotFoundException e) { e.printStackTrace(); } } public static Connection getConn(){ try { conn = DriverManager.getConnection(ConfigUtil.getValue("url"), ConfigUtil.getValue("username"), ConfigUtil.getValue("password")); } catch (SQLException e) { e.printStackTrace(); } return conn; } /* * 查询 * */ public ResultSet search(String sql){ try { rs = ps.executeQuery(); return rs; } catch (SQLException e) { throw new RuntimeException(); } } /* * 更新数据 * */ public int modify(String sql){ try { return ps.executeUpdate(sql); } catch (SQLException e) { throw new RuntimeException(); } } public static void close(ResultSet rs, PreparedStatement ps, Connection conn){ try { if(rs != null) { rs.close(); } if(ps != null) { ps.close(); } if(conn != null) { conn.close(); } } catch (SQLException e) { e.printStackTrace(); } }}=================ConfigUtil.java==============//本页封装了从配置文件读取数据的方法package com.ibeifeng.student;import java.io.IOException;import java.io.InputStream;import java.util.Properties;public class ConfigUtil { //通过key获取jdbc配置的value public static String getValue(String key){ Properties pro = new Properties(); //获取流信息 InputStream is = ConfigUtil.class.getResourceAsStream("/jdbc.properties"); try { //加载流文件 pro.load(is); //获取属性值 return pro.getProperty(key); } catch (IOException e) { throw new RuntimeException(); } }}================StudentDao.java==============//本页封装了对于数据库，数据处理的一些方法package com.ibeifeng.student;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;public class StudentDao { /* * Student Dao用于处理Student类 * */ Connection conn = null; PreparedStatement ps = null; public int updateStu(Student stu){ /* * 更新学员信息 * */ String sql = "update student set stu_name=?,pwd=?,sex=?,email=? where stu_id=?"; try { ps = BaseDao.getConn().prepareStatement(sql); ps.setString(1,stu.getName()); ps.setString(2,stu.getPwd()); ps.setInt(3,stu.getSex()); ps.setString(4,stu.getEmail()); ps.setInt(5,stu.getId()); return ps.executeUpdate(); } catch (SQLException e) { throw new RuntimeException(); }finally { BaseDao.close(null,ps,conn); } } public Student getStuByStuId(String stu_id){ String sql = "select * from student where stu_id=?"; Student stu = null; try { conn = BaseDao.getConn(); ps = conn.prepareStatement(sql); int sid = Integer.parseInt(stu_id); ps.setInt(1,sid); ResultSet rs = ps.executeQuery(); if(rs.next()){ stu = new Student(); stu.setId(rs.getInt("stu_id")); stu.setName(rs.getString("stu_name")); stu.setPwd(rs.getString("pwd")); stu.setSex(rs.getInt("sex")); stu.setEmail(rs.getString("email")); } } catch (SQLException e) { e.printStackTrace(); }finally { BaseDao.close(null,ps,conn); } return stu; } /* * 根据学号删除学生信息 * */ public int delStu(String sid){ String sql = "delete from student where stu_id = ?"; conn = BaseDao.getConn(); try { ps = conn.prepareStatement(sql); int id = Integer.parseInt(sid); ps.setInt(1,id); return ps.executeUpdate(); } catch (SQLException e) { throw new RuntimeException(); } }}===================Student.java==============//封装类对象package com.ibeifeng.student;public class Student { private int id; private String name; private String pwd; private int sex; private String email; public Student(){} public void setId(int id) { this.id = id; } public void setName(String name) { this.name = name; } public void setPwd(String pwd) { this.pwd = pwd; } public void setSex(int sex) { this.sex = sex; } public void setEmail(String email) { this.email = email; } public int getId() { return id; } public String getName() { return name; } public String getPwd() { return pwd; } public int getSex() { return sex; } public String getEmail() { return email; }}=============jdbc.properties=============//配置文件信息driver=com.mysql.jdbc.Driverurl=jdbc:mysql://localhost:3306/testusername=rootpassword=123456

 

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