目录
实现流程和思路
创建jsp页面，然后转发到servlet下，接受jsp页面传过来的值，拿着这些值去访问service服务层接口，服务层写个实类，这个实现类去服务层的接口，然后这个服务层的实现类再去访问dao层的接口，在持久层dao中在编写一个dao层接口的实现类去实现dao层的接口，最后在dao层的的实现类去访问数据库。
图示：
项目视频演示
学生管理系统项目演示
设置数据库studenttest
①、创建user表
其中包括设置删除的u_isdelete（0是存在，1是删除）
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create table user( u_name varchar(20), u_id int primary key auto_increment, u_pwd varchar(20) , u_phone varchar(20) not null, u_role int not null, u_isdelete int not null ) charset=utf8; |
创建项目
项目界面总览
jsp页面
登录界面login.jsp
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<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8" %> <% String path = request.getContextPath(); String basepath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/"; %> <html> <head> <base href="<%=basepath %>"/> <meta charset="utf-8"/> <title>登录界面</title> <%-- css代码--%> <style> #fame_{ width: 500px; height: 400px; margin-left: 600px; margin-top: 200px; background-color: aqua; /*边框黑色 实线 2像素*/ border: black solid 2px; } #inner_{ margin-left: 140px; margin-top: 160px; } </style> </head> <body> <h1 align="center" style="color: red">登录界面</h1> <div id="fame_" > <div id="inner_"> 用户:<input type="text" id="u_id"> <b> <span id="span1" style="color: crimson">${error}</span></b><br><br> 密码:<input type="password" id="u_pwd"> <b> <span id="span2" style="color: crimson"></span></b><br><br> <button id="btn01">重置</button> <button id="btn02" style="margin-left: 20px">登录</button><br> <script> <%-- 这里写js代码验证账号密码值是否为空--%> window.onload=function() { document.getElementById("btn02").onclick = function () { let id_value = document.getElementById("u_id").value if (id_value == null || id_value == "") { document.getElementById("span1").innerHTML = "用户名不能为空" return; } //判断密码是否为空 let pwd = document.getElementById("u_pwd").value if (pwd == null || pwd == "") { document.getElementById("span2").innerHTML = "密码不能为空" return; } //跳转到servlet window.location.href = "login?u_id=" + id_value + "&u_pwd=" + pwd; } //在次点击清空错误信息 document.getElementById("u_id").onfocus = function () { document.getElementById("span1").innerText = "" } document.getElementById("u_pwd").onfocus = function () { document.getElementById("span2").innerText = "" } //清空内容 document.getElementById("btn01").onclick=function () { document.getElementById("u_id").value=""; document.getElementById("u_pwd").value=""; } } </script> </div> </div> </body> </html> |
主界面mainPage.jsp
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<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8" %> <% String path = request.getContextPath(); String basepath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/"; %> <%--JSTL语法，可以使用user.getName()方法--%> <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <html> <head> <title>主界面</title> <style> #head_{ height: 100px; width: 100%; background-color: darkcyan; } #personFile{ width: 120px; height: 50px; padding-top: 25px; margin-left: 90%; } #search{ height: 70px; width: 100%; background-color: aqua; } #inner_s{ /*width: 200px; height: 40px; padding-right: 70%; padding-top: 50%;*/ width: 30%; padding-top:25px; padding-left: 45%; } #table{ margin-left: 30%; margin-top: 30px; } td{ text-align: center; height: 20px; width: 150px; border: darkcyan 2px solid; padding:6px; } </style> </head> <body> <div id="head_"> <h2> <div id="personFile" > 名字:<span style="color: red">${user.getU_name()}</span><br> 编号:<span style="color: red">${user.getU_id()}</span> </div> </h2> </div> <div id="search"> <div id="inner_s"> <input type="text" style="font-size: 20px; height: 26px;width: 190px " id="fileId">&nbsp;&nbsp; <button style="font-size: 18px; height: 28px;" id="cx"margin-left: 30px>查询</button> <button style="font-size: 18px; height: 28px;" id="addUser" margin-left: 100px>添加</button> <button style="font-size: 18px; height: 28px;" id="deleteUser">删除</button> <button style="font-size: 18px; height: 28px;" id="changeUser">修改</button> <b> <span style="color: crimson">${tip}</span></b> </div> </div> <script> //提交 document.getElementById("cx").onclick=function(){ let v = document.getElementById('fileId').value; //访问服务器searchServlet window.location.href = "searchServlet?v=" + v+"&id=${user.getU_name()}"; } //删除 document.getElementById("deleteUser").onclick=function () { let v =document.getElementById('fileId').value; window.location.href = "deleteServlet?v="+v+"&id=${user.getU_name()}"; } // 添加跳转到AddUser.jsp界面 document.getElementById("addUser").onclick=function () { window.location = "AddUser.jsp"; } //修改，跳转到change.jsp document.getElementById("changeUser").onclick=function () { let v =document.getElementById('fileId').value; window.location.href = "change.jsp"; } </script> <div> <table id="table" style="height: 30px;width: 700px;border: black 1px solid;border-collapse:collapse;"> <tr style="font-weight: bold" > <td>学生id</td> <td>学生名字</td> <td>学生电话</td> <td>学生成绩</td> <td>学生品行</td> </tr> <%--jstl语法遍历,var是一个指指针--%> <c:forEach items="${arr}" var="item"> <tr> <td>${item.getU_id()}</td> <td>${item.getU_name()}</td> <td>${item.getU_phone()}</td> <td style="color: deeppink"> 优秀</td> <td style="color: red">良好</td> </td> </tr> </c:forEach> </table> </div> <div> </div> </body> </html> |
添加学生信息AddUser.jsp
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<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8" %> <% String path = request.getContextPath(); String basepath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/"; %> <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <html> <head> <base href="<%=basepath %>"/> <meta charset="utf-8"/> <title>添加信息界面</title> </head> <style> #div1{ width: 400px; height: 300px; margin-left: 600px; margin-top: 200px; background-color:deepskyblue; /*边框黑色 实线 2像素*/ border: black solid 2px; } </style> <body> <h2 align="center" >添加学生信息</h2><br><br> <div id="div1" > <tr> 学生id:<input type="text" id="u_id" > <span id="span01" style="color: red"></span> <br><br></tr> <tr> 姓名:<input type="text" id="u_name" ><br><br></tr> <tr> 密码:<input type="password" id="u_pwd"><br><br></tr> <tr> 电话号码:<input type="text" id="u_phone"><br><br></tr> <button id="btn3">提交</button> <script> document.getElementById("btn3").onclick=function(){ //获取填写的数据 let u_id=document.getElementById("u_id").value; let u_name=document.getElementById("u_name").value; let u_pwd=document.getElementById("u_pwd").value; let u_phone=document.getElementById("u_phone").value; if(u_id==null||u_id==""||u_name==null||u_name==""){ document.getElementById("span01").innerText="id或名字为为空" }else{ //把数据发送到后端，发送到servlet的addUser路径下 window.location.href="addUser?u_id="+u_id+"&u_pwd="+u_pwd+"&u_name="+u_name+"&u_phone="+u_phone+"&id=${user.getU_name()}"; } } document.getElementById("u_id").onfocus=function () { document.getElementById("span01").innerText="" } </script> </div> </body> </html> |
修改学生信息change.jsp
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<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8" %> <% String path = request.getContextPath(); String basepath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/"; %> <html> <head> <base href="<%=basepath %>"/> <meta charset="utf-8"/> <title>修改界面</title> </head> <style> #div1{ width: 400px; height: 300px; margin-left: 600px; margin-top: 200px; background-color:deepskyblue; /*边框黑色 实线 2像素*/ border: black solid 2px; } </style> <body> <h2 align="center" >修改学生信息</h2><br><br> <div id="div1" > 修改的学生id:<input type="text" id="u_id" > <span id="span01" style="color: red"></span> <br><br> 姓名:<input type="text" id="u_name" ><br><br> 密码:<input type="password" id="u_pwd"><br><br> 电话号码:<input type="text" id="u_phone"><br><br> <button id="btn3">提交</button> <script> //获取填写数据 document.getElementById("btn3").onclick=function(){ let u_id=document.getElementById("u_id").value; let u_name=document.getElementById("u_name").value; let u_pwd=document.getElementById("u_pwd").value; let u_phone=document.getElementById("u_phone").value; //判断非空 if(u_id==null||u_id==""||u_name==null||u_name==""){ document.getElementById("span01").innerText="id或名字为为空" }else{ //不为空就转发到后端 window.location.href="changeUser?u_id="+u_id+"&u_pwd="+u_pwd+"&u_name="+u_name+"&u_phone="+u_phone+"&id=${user.getU_name()}"; } } //再次点击清除错误信息提示 document.getElementById("u_id").onfocus=function () { document.getElementById("span01").innerText="" } </script> </div> </body> </html> |
Servlet下
登录LoginServlet
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package com.StudentTest.Servlet; import com.StudentTest.pojo.User; import com.StudentTest.service.FileService; import com.StudentTest.service.FileServiceImpl; 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.util.ArrayList; @WebServlet("/login") public class LoginServlet extends HttpServlet { @Override protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { String u_id=null,u_pwd=null; User u = new User(); try{//非数字异常判断 u_id = req.getParameter("u_id"); u_pwd = req.getParameter("u_pwd"); u.setU_id(Integer.valueOf(u_id)); u.setU_pwd(u_pwd); }catch (Exception e){ req.setAttribute("error", "你输入的不是数字"); //错误就回到主界面 req.getRequestDispatcher("login.jsp").forward(req, resp); } //实现登录服务层的业务逻辑层，从服务层service到持久层dao FileService fs=new FileServiceImpl(); //返回user这样可以看到登录的用户是谁 /** * 如果user为空说明账号密码不一致，跳转到登录界面 * 不为空说明账号密码一致，跳转到主界面 */ User user = null; try { user = fs.loginService(u); } catch (Exception e) { e.printStackTrace(); } if (user != null) { fs=new FileServiceImpl(); //查看所有数据 ArrayList<User> arrUser=fs.getAllStudent(); //将这些数据转发到前端 req.setAttribute("arr",arrUser); req.setAttribute("user", user); //跳转到主界面 req.getRequestDispatcher("mainPage.jsp").forward(req, resp); } else { req.setAttribute("error", "密码不匹配"); req.getRequestDispatcher("login.jsp").forward(req, resp); } } } |
查找SearchServlet
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package com.StudentTest.Servlet; import com.StudentTest.pojo.User; import com.StudentTest.service.FileService; import com.StudentTest.service.FileServiceImpl; 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.util.ArrayList; @WebServlet("/searchServlet") public class SearchServlet extends HttpServlet { @Override protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { //设置字符集为 req.setCharacterEncoding("UTF-8"); String v=req.getParameter("v"); //访问service层，在由service访问dao层 FileService fs=new FileServiceImpl(); //创建service方法到dao层中去访问 User u=fs.searchIdName(v); //创建集合用来接受dao层访问后的数据 ArrayList<User> arr=new ArrayList<>(); //将数据添加到集合中去 arr.add(u); //获取登录人员的信息 String id=req.getParameter("id"); //创建service服务层，通过service访问doa层 FileService fs2=new FileServiceImpl(); //通过一连串的访问，最终去访问 User admine=fs2.getAdmint(id); //将登录的信息发送到前端 req.setAttribute("user", admine); //如果访问的信息不为空 if(u!=null){ //管理员信息 req.setAttribute("arr",arr); //跳转到主界面 req.getRequestDispatcher("mainPage.jsp").forward(req, resp); }else{ FileService f=new FileServiceImpl(); ArrayList<User> arr2=f.getAllStudent(); req.setAttribute("arr", arr2); req.getRequestDispatcher("mainPage.jsp").forward(req, resp); } } } |
删除DeleteServlet
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package com.StudentTest.Servlet; import com.StudentTest.pojo.User; import com.StudentTest.service.FileService; import com.StudentTest.service.FileServiceImpl; 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.util.ArrayList; @WebServlet("/deleteServlet") public class DeleteServlet extends HttpServlet { @Override protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { req.setCharacterEncoding("UTF-8"); String del=req.getParameter("v"); //获取登录人信息 String adm=req.getParameter("id"); //访问service层，在service层创建对应的方法 FileService fs=new FileServiceImpl(); ArrayList<User> list=fs.getAllStudent(); //获取登录人员信息 User u = fs.getAdmint(adm); //service层调用方法，转到dao层执行sql语句 boolean user=fs.delUser(del); String tip=""; if(user){ tip="删除成功"; }else { tip="删除失败"; } //发送到前端 req.setAttribute("user", u); req.setAttribute("arr", list); req.setAttribute("tip", tip); req.getRequestDispatcher("mainPage.jsp").forward(req, resp); } } |
修改ChangeServlet
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package com.StudentTest.Servlet; import com.StudentTest.pojo.User; import com.StudentTest.service.FileService; import com.StudentTest.service.FileServiceImpl; 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.util.ArrayList; @WebServlet("/changeUser") public class ChangeServlet extends HttpServlet { @Override protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { req.setCharacterEncoding("UTF-8"); String id=req.getParameter("u_id"); String pwd=req.getParameter("u_pwd"); String phone=req.getParameter("u_phone"); String name=req.getParameter("u_name"); FileService fs=new FileServiceImpl(); User user=new User(name,Integer.valueOf(id),pwd,phone); String adm=req.getParameter("id"); //获取登录人员信息 User u = fs.getAdmint(adm); System.out.println(u); boolean flag=fs.changeUser( user); ArrayList<User> list=fs.getAllStudent(); String tip=""; if (flag){ tip="修改成功"; }else{ tip="修改失败"; } //发送到前端 req.setAttribute("tip",tip); req.setAttribute("user", u); req.setAttribute("arr", list); req.getRequestDispatcher("mainPage.jsp").forward(req, resp); } } |
添加addServlet
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package com.StudentTest.Servlet; import com.StudentTest.pojo.User; import com.StudentTest.service.FileService; import com.StudentTest.service.FileServiceImpl; 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.util.ArrayList; @WebServlet("/addUser") public class AddServlet extends HttpServlet { @Override protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { req.setCharacterEncoding("UTF-8"); String id=req.getParameter("u_id"); String pwd=req.getParameter("u_pwd"); String phone=req.getParameter("u_phone"); String name=req.getParameter("u_name"); FileService fs=new FileServiceImpl(); User user=new User(name,Integer.valueOf(id),pwd,phone); String adm=req.getParameter("id"); //获取登录人员信息 User u = fs.getAdmint(adm); System.out.println(u); boolean flag=fs.addUser( user); ArrayList<User> list=fs.getAllStudent(); String tip=""; if (flag){ tip="添加成功"; }else{ tip="添加失败"; } //发送到前端 req.setAttribute("tip",tip); req.setAttribute("user", u); req.setAttribute("arr", list); req.getRequestDispatcher("mainPage.jsp").forward(req, resp); } } |
Service下
FileServic接口下
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package com.StudentTest.service; import com.StudentTest.pojo.User; import java.util.ArrayList; public interface FileService { ArrayList<User> getAllStudent(); User searchIdName(String v); User getAdmint(String id); boolean delUser(String del); boolean addUser(User user); boolean changeUser(User user); User loginService(User u) throws Exception; } |
FileServiceImpl实现类下
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package com.StudentTest.service; import com.StudentTest.Dao.FileDao; import com.StudentTest.Dao.FileDaoImpl; import com.StudentTest.pojo.User; import java.util.ArrayList; public class FileServiceImpl implements FileService { FileDao fd= new FileDaoImpl(); @Override public ArrayList<User> getAllStudent() { /** * 访问持久层 */ return fd.getAllStudent(); } @Override public User searchIdName(String v) { return fd.searchIdName( v); } @Override public User getAdmint(String id) { return fd.getAdmint(id); } @Override public boolean delUser(String del) { return fd.delUser(del ); } @Override public boolean addUser(User user) { return fd.addUser(user); } @Override public boolean changeUser(User user) { return fd.changeUser(user); } @Override public User loginService(User u) throws Exception { return fd.loginDao( u); } } |
pojo下
User学生类
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package com.StudentTest.pojo; public class User { private String u_name; private int u_id; private String u_pwd; private String u_phone; private int u_role; private int u_isdelete; public User() { } public User(String u_name, int u_id, String u_pwd, String u_phone) { this.u_name = u_name; this.u_id = u_id; this.u_pwd = u_pwd; this.u_phone = u_phone; } public User(String u_name, int u_id, String u_pwd, String u_phone, int u_role, int u_isdelete) { this.u_name = u_name; this.u_id = u_id; this.u_pwd = u_pwd; this.u_phone = u_phone; this.u_role = u_role; this.u_isdelete = u_isdelete; } public String getU_name() { return u_name; } public void setU_name(String u_name) { this.u_name = u_name; } public int getU_id() { return u_id; } public void setU_id(int u_id) { this.u_id = u_id; } public String getU_pwd() { return u_pwd; } public void setU_pwd(String u_pwd) { this.u_pwd = u_pwd; } public String getU_phone() { return u_phone; } public void setU_phone(String u_phone) { this.u_phone = u_phone; } public int getU_role() { return u_role; } public void setU_role(int u_role) { this.u_role = u_role; } public int getU_isdelete() { return u_isdelete; } public void setU_isdelete(int u_isdelete) { this.u_isdelete = u_isdelete; } @Override public String toString() { return "User{" + "u_name='" + u_name + '\'' + ", u_id=" + u_id + ", u_pwd='" + u_pwd + '\'' + ", u_phone='" + u_phone + '\'' + ", u_role=" + u_role + ", u_isdelete=" + u_isdelete + '}'; } } |
Dao下
FileDao接口下
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package com.StudentTest.Dao; import com.StudentTest.pojo.User; import java.util.ArrayList; public interface FileDao { ArrayList<User> getAllStudent(); User searchIdName(String v); User getAdmint(String id); boolean delUser(String del); boolean addUser(User user); boolean changeUser(User user); User loginDao(User u) throws Exception; } |
FileDaoImpl实现类下
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package com.StudentTest.Dao; import com.StudentTest.pojo.User; import com.utils.JDBCUtils; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; public class FileDaoImpl implements FileDao { @Override public User loginDao(User u) throws SQLException, ClassNotFoundException { /**在这写数据库的内容 * 获取链接对象，获取sql语句 */ int id=u.getU_id(); String pwd=u.getU_pwd(); // //访问数据库 // User user=new User("慧宝",1001,"520","1314",1,0); Connection connection= JDBCUtils.getConnection(); PreparedStatement pre =null; ResultSet res =null; String sql="select *from user where u_id="+id+" and u_pwd='"+pwd+"'"; try{ pre= connection.prepareStatement(sql); res=pre.executeQuery(); User user=new User(); while(res.next()){ user.setU_id(res.getInt("u_id")); user.setU_name(res.getString("u_name")); user.setU_pwd(res.getString("u_pwd")); user.setU_phone(res.getString("u_phone")); user.setU_role(res.getInt("u_role")); user.setU_isdelete(res.getInt("u_isdelete")); return user; } } catch (SQLException s){ s.printStackTrace(); } return null; } //获取所有学生信息 @Override public ArrayList<User> getAllStudent() { ArrayList<User> arr=new ArrayList<>(); Connection connection= null; try { connection = JDBCUtils.getConnection(); } catch (Exception e) { } PreparedStatement pre =null; ResultSet res =null; //u_role为1表示普通用户，为0为管理员，u_isdelete为0表示还在，为1表示已删除 String sql="select *from user where u_role=1 and u_isdelete=0 "; try{ pre= connection.prepareStatement(sql); res=pre.executeQuery(); while(res.next()){ User user=new User(); user.setU_id(res.getInt("u_id")); user.setU_name(res.getString("u_name")); user.setU_pwd(res.getString("u_pwd")); user.setU_phone(res.getString("u_phone")); user.setU_role(res.getInt("u_role")); user.setU_isdelete(res.getInt("u_isdelete")); arr.add(user); } return arr; } catch (SQLException s){ s.printStackTrace(); } return null; } //找指定学生 @Override public User searchIdName(String v) { /** * sql */ Connection connection= null; try { connection = JDBCUtils.getConnection(); } catch (Exception e) { } PreparedStatement pre =null; ResultSet res =null; //u_role为1表示普通用户，为0为管理员，u_isdelete为0表示还在，为1表示已删除 String sql="select *from user where u_id ='"+v+"'or+ u_name ='"+v+"' "; try{ pre= connection.prepareStatement(sql); res=pre.executeQuery(); while(res.next()){ User user=new User(); user.setU_id(res.getInt("u_id")); user.setU_name(res.getString("u_name")); user.setU_pwd(res.getString("u_pwd")); user.setU_phone(res.getString("u_phone")); user.setU_role(res.getInt("u_role")); user.setU_isdelete(res.getInt("u_isdelete")); return user; } } catch (SQLException s){ s.printStackTrace(); } return null; } //获取登录人员信息 @Override public User getAdmint(String id) { Connection connection= null; try { connection = JDBCUtils.getConnection(); } catch (Exception e) { } PreparedStatement pre =null; ResultSet res =null; String sql="select *from user where u_id ='"+id+"'or+ u_name ='"+id+"' "; try{ pre= connection.prepareStatement(sql); res=pre.executeQuery(); while(res.next()){ User user=new User(); user.setU_id(res.getInt("u_id")); user.setU_name(res.getString("u_name")); return user; } } catch (SQLException s){ s.printStackTrace(); } return null; } //删除信息 @Override public boolean delUser(String del) { Connection connection= null; try { connection = JDBCUtils.getConnection(); } catch (Exception e) { } PreparedStatement pre =null; ResultSet ress=null; int res=0; String sql="delete from user where u_name ='"+del+"'or + u_id ='"+del+"' "; try{ pre= connection.prepareStatement(sql); res=pre.executeUpdate(); if(res>0)return true; } catch (SQLException s){ s.printStackTrace(); } return false; } //添加学生 @Override public boolean addUser(User user) { Connection connection= null; try { connection = JDBCUtils.getConnection(); } catch (Exception e) { } PreparedStatement pre =null; ResultSet ress=null; String name=user.getU_name(); int id=user.getU_id(); String pwd=user.getU_pwd(); String phone=user.getU_phone(); int res=0; //"insert into user values('"+user.getU_name()+"','"+user.getU_id()+"','"+user.getU_pwd()+"','"+user.getU_phone()+"')" String sql="insert into user(u_name,u_id,u_pwd,u_phone)\n" + "values('"+name+"','"+id+"','"+pwd+"','"+phone+"')"; try{ pre= connection.prepareStatement(sql); res=pre.executeUpdate(); System.out.println(res); if(res>=0)return true; } catch (SQLException s){ s.printStackTrace(); } return false; } //修改信息 @Override public boolean changeUser(User user) { Connection connection= null; try { connection = JDBCUtils.getConnection(); } catch (Exception e) { } PreparedStatement pre =null; ResultSet ress=null; String name=user.getU_name(); int id=user.getU_id(); String pwd=user.getU_pwd(); String phone=user.getU_phone(); int res=0,res1=0; String sql1="delete from user where u_id="+id; try{ pre= connection.prepareStatement(sql1); res=pre.executeUpdate(); if (res>0){ String sql="insert into user(u_name,u_id,u_pwd,u_phone)\n" + "values('"+name+"','"+id+"','"+pwd+"','"+phone+"')"; pre= connection.prepareStatement(sql); res1=pre.executeUpdate(); } System.out.println(res); if(res1>0)return true; } catch (SQLException s){ s.printStackTrace(); } return false; } } |
utils下
JDBCUtils
|
1 |
package com.utils; import java.sql.*; public class JDBCUtils { public static Connection getConnection() throws SQLException, ClassNotFoundException { Class.forName("com.mysql.cj.jdbc.Driver"); String url="jdbc:mysql://localhost:3306/studenttest?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone = GMT"; String username="root"; String password="123456"; Connection conn= DriverManager.getConnection(url,username,password); return conn; } public static void release(Statement stmt,Connection conn){ if(stmt!=null){ try{ stmt.close(); }catch(SQLException e){ e.printStackTrace(); } stmt=null; } if(conn!=null){ try{ conn.close(); }catch (SQLException e){ e.printStackTrace(); } conn=null; } } public static void release(ResultSet rs,Statement stmt,Connection conn){ if(rs!=null){ try{ rs.close(); }catch (SQLException e){ e.printStackTrace(); } rs=null; } release(stmt,conn); } } |
还有写web-inf下lib下的jar包
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