java web简单的增删改查

1、主要的文件，运行结果，运行界面，数据库创建的表等图片。

所要创建的文件和要导入的包：

主页面：

显示界面：

数据库的信息：

删除、查找、修改就不一 一列出来，自己可以运行看看。哈哈

2、接下来我将给你分享一下我的代码：

//User类

 1 package com.newjavaweb;
 2 public class User implements Comparable{
 3     private String id;
 4     private String name;
 5     private String clas;
 6     private String ke;
 7     private String score;
 8
 9     public String getId() {
10         return id;
11     }
12
13     public void setId(String id) {
14         this.id = id;
15     }
16
17     public String getName() {
18         return name;
19     }
20
21     public void setName(String name) {
22         this.name = name;
23     }
24
25     public String getClas() {
26         return clas;
27     }
28
29     public void setClas(String clas) {
30         this.clas = clas;
31     }
32
33     public String getKe() {
34         return ke;
35     }
36
37     public void setKe(String ke) {
38         this.ke = ke;
39     }
40
41     public String getScore() {
42         return score;
43     }
44
45     public void setScore(String score) {
46         this.score = score;
47     }
48
49     public User(String id, String name, String clas, String ke, String score) {
50         super();
51         this.id = id;
52         this.name = name;
53         this.clas = clas;
54         this.ke = ke;
55         this.score = score;
56     }
57     public int compareTo(Object o)
58     {
59         User s=(User)o;
60         int result = 0;
61         if(score.length()==s.score.length()) {
62             if(score.compareTo(s.score)>0)
63                 result=1;
64             else if(score.compareTo(s.score)<0)
65                 result=-1;
66         }
67         if(score.length()>s.score.length())
68             result=1;
69         if(score.length()<s.score.length())
70             result=-1;
71         return result;
72     }
73 }

//userdao类

  1 package Dao;
  2
  3 import java.io.IOException;
  4 import java.sql.Connection;
  5 import java.sql.PreparedStatement;
  6 import java.sql.ResultSet;
  7 import java.sql.SQLException;
  8 import java.sql.Statement;
  9 import java.util.ArrayList;
 10 import java.util.Arrays;
 11 import java.util.Collections;
 12 import java.util.Comparator;
 13 import java.util.List;
 14 import javax.servlet.ServletException;
 15 import javax.servlet.ServletResponse;
 16 import javax.servlet.http.HttpServletRequest;
 17 import javax.servlet.http.HttpServletResponse;
 18 import util.DBUtil;
 19 import com.newjavaweb.User;
 20
 21 public class userdao {
 22     public boolean add(User user) {
 23         String sql = "insert into text(id,name,clas,ke,score)" + "values('"  + user.getId() + "','" + user.getName()+ "','" + user.getClas()  + "','" + user.getKe()+ "','" + user.getScore()+ "')";
 24         Connection conn = DBUtil.getConn();//调用方法连接数据库
 25         Statement state = null;//创建一个Statement对象来执行静态的SQL语句
 26         //Statement用于在已经建立数据库连接上发送静态的SQL语句
 27         boolean f = false;
 28         int a = 0 ;
 29
 30         try {       //监视大括号内的代码
 31             state = conn.createStatement();//上面的是详解
 32             a = state.executeUpdate(sql);
 33             //执行指定的更新类的SQl语句，并返回操作结果的整型值
 34         } catch (Exception e) {     //捕获错误
 35             e.printStackTrace();
 36         } finally {
 37             //关闭z    连接
 38             DBUtil.close(state, conn);
 39         }
 40
 41         if (a > 0) {
 42             f = true;
 43         }
 44         return f;
 45     }
 46
 47
 48     public static List<User> loadview(String sql) {
 49         // TODO Auto-generated method stub
 50         String sql1="select * from text "+ sql;
 51         List<User> list =new ArrayList<User>();
 52         Connection con=null;
 53         PreparedStatement psts=null;
 54         ResultSet rs=null;
 55             try
 56             {
 57                 con=DBUtil.getConn();
 58                 //String sql="select * from course";
 59                 psts=con.prepareStatement(sql1);
 60                 rs=psts.executeQuery();//记录返回的结果
 61                 while(rs.next())
 62                 {
 63                     String id=rs.getString("id");
 64                     String name=rs.getString("name");
 65                     String clas=rs.getString("clas");
 66                     String ke=rs.getString("ke");
 67                     String score=rs.getString("score");
 68
 69                     User yi=new User(id,name,clas,ke,score);
 70                     list.add(yi);
 71                 }
 72
 73                 DBUtil.close(rs, psts, con);
 74             } catch (SQLException e) {
 75                 // TODO 自动生成的 catch 块
 76                 e.printStackTrace();
 77             }
 78
 79         return list;
 80     }
 81         //return null;
 82
 83
 84
 85
 86     public String find(String name)
 87     {
 88         String sql = "select * from text where ";
 89         if (name!= "") {
 90             sql += "name like '" + name +"'";
 91         }
 92         Connection conn = DBUtil.getConn();
 93         Statement state = null;
 94         ResultSet rs = null;
 95         String username2="@";
 96         try {
 97             state = conn.createStatement();
 98             rs = state.executeQuery(sql);
 99             while (rs.next()) {
100
101                 username2 = rs.getString("name");
102
103             }
104         } catch (SQLException e) {
105             e.printStackTrace();
106         } finally {
107             DBUtil.close(rs, state, conn);
108         }
109         return username2;
110     }
111
112     public String search(String name) {
113         String sql = "select * from text where ";
114         if (name!= "") {
115             sql += "name like '%" + name + "%'";
116         }
117
118         Connection conn = DBUtil.getConn();
119         Statement state = null;
120         ResultSet rs = null;
121         String name2 = "@";
122         try {
123             state = conn.createStatement();
124             rs = state.executeQuery(sql);
125             while (rs.next()) {
126
127                 name2 = rs.getString("name");
128
129             }
130         } catch (SQLException e) {
131             e.printStackTrace();
132         } finally {
133             DBUtil.close(rs, state, conn);
134         }
135
136         return name2;
137     }
138
139
140     public String search1(String id, String name, String clas, String ke, String score) {
141         String sql = "select * from text where ";
142         if (id!= "") {
143             sql += "id like '%" + id + "%'";
144         }
145         else if(name!="")
146         {
147             sql += "name like '%" + name + "%'";
148         }
149         else if(clas!="")
150         {
151             sql += "clas like '%" + clas + "%'";
152         }
153         else if(ke!="")
154         {
155             sql += "ke like '%" + ke + "%'";
156         }
157         else if(score!="")
158         {
159             sql += "score like '%" + score + "%'";
160         }
161         Connection conn = DBUtil.getConn();
162         Statement state = null;
163         ResultSet rs = null;
164         String name2 = "@";
165         try {
166             state = conn.createStatement();
167             rs = state.executeQuery(sql);
168             while (rs.next()) {
169
170                 name2 = rs.getString("name");
171
172             }
173         } catch (SQLException e) {
174             e.printStackTrace();
175         } finally {
176             DBUtil.close(rs, state, conn);
177         }
178
179         return name2;
180     }
181
182     public List<User> examine(String name1) throws ServletException, IOException {
183         String sql = "select * from text where ";
184         if (name1!= "") {
185             sql += "name like '%" + name1 + "%'";
186         }
187         List<User> list1 = new ArrayList<>();
188         Connection conn = DBUtil.getConn();
189         Statement state = null;
190         ResultSet rs = null;
191         try {
192             state = conn.createStatement();
193             rs = state.executeQuery(sql);
194             while (rs.next()) {
195                 String id=rs.getString("id");
196                 String name=rs.getString("name");
197                 String clas=rs.getString("clas");
198                 String ke=rs.getString("ke");
199                 String score=rs.getString("score");
200             User bean2 = new User(id,name,clas,ke,score);
201             list1.add(bean2);
202             }
203         } catch (SQLException e) {
204             e.printStackTrace();
205         } finally {
206             DBUtil.close(rs, state, conn);
207         }
208         return list1;
209     }
210
211     public List<User>  theall() {
212         String sql = "select * from text";//全部
213         List<User> list = new ArrayList<>();
214         Connection conn = DBUtil.getConn();
215         Statement state = null;
216         ResultSet rs = null;
217         try {
218             state = conn.createStatement();
219             rs = state.executeQuery(sql);
220             User bean = null;
221             if(rs!=null) {
222                 while (rs.next()) {
223                     String id=rs.getString("id");
224                     String name=rs.getString("name");
225                     String clas=rs.getString("clas");
226                     String ke=rs.getString("ke");
227                     String score=rs.getString("score");
228                     bean = new User(id,name,clas,ke,score);
229                     list.add(bean);
230                 }
231             }
232         } catch (SQLException e) {
233             e.printStackTrace();
234         } finally {
235             DBUtil.close(rs, state, conn);
236         }
237         return list;
238     }
239
240
241
242
243     public boolean delete (String  name) {
244          boolean f = false;
245          String sql = "delete from text where name='" + name + "'";
246          Connection conn = DBUtil.getConn();
247          Statement state = null;
248          int a = 0;
249          try {
250           state = conn.createStatement();
251           a = state.executeUpdate(sql);
252               } catch (SQLException e) {
253                      e.printStackTrace();
254               }
255               finally {
256               DBUtil.close(state, conn);
257              }
258
259                if (a > 0) {
260                      f = true;
261                  }
262                  return f;
263             }
264
265
266
267      public User getUserbyzhanghu(String name5) {
268          String sql = "select * from text where name ='" + name5 + "'";
269          Connection conn = DBUtil.getConn();
270          Statement state = null;
271          ResultSet rs = null;
272          User user3 = null;
273          try {
274             state = conn.createStatement();
275            rs = state.executeQuery(sql);
276            while (rs.next()) {
277                String id=rs.getString("id");
278                String name=rs.getString("name");
279                String clas=rs.getString("clas");
280                String ke=rs.getString("ke");
281                String score=rs.getString("score");
282                  user3= new User(id,name,clas,ke,score);
283            }
284           } catch (Exception e) {
285              e.printStackTrace();
286           } finally {
287              DBUtil.close(rs, state, conn);
288           }
289           return user3;
290      }
291
292     public boolean update(User user,String zh)
293         {
294             String sql="update text set id='" + user.getId() + "',name='" + user.getName() + "',clas='" + user.getClas() + "',ke='" + user.getKe() + "',score='" + user.getScore() + "' where name='" + zh + "'";
295              Connection conn = DBUtil.getConn();
296                 Statement state = null;
297                 boolean f = false;
298                 int a = 0;
299
300                 try {
301                     state = conn.createStatement();
302                     a = state.executeUpdate(sql);
303                 } catch (SQLException e) {
304                     e.printStackTrace();
305                 } finally {
306                     DBUtil.close(state, conn);
307                 }
308
309                 if (a > 0) {
310                     f = true;
311                 }
312                 return f;
313         }
314     public List<User> paixu(){
315         String sql = "select * from text";//全部
316         List<User> list = new ArrayList<>();
317         Connection conn = DBUtil.getConn();
318         Statement state = null;
319         ResultSet rs = null;
320         try {
321             state = conn.createStatement();
322             rs = state.executeQuery(sql);
323             User bean = null;
324             if(rs!=null) {
325                 while (rs.next()) {
326                     String id=rs.getString("id");
327                     String name=rs.getString("name");
328                     String clas=rs.getString("clas");
329                     String ke=rs.getString("ke");
330                     String score=rs.getString("score");
331                     bean = new User(id,name,clas,ke,score);
332                     list.add(bean);
333                 }
334             }
335         } catch (SQLException e) {
336             e.printStackTrace();
337         } finally {
338             DBUtil.close(rs, state, conn);
339         }
340         list.sort(null);
341         return list;
342     }
343 }

//Servlet类

  1 package servlet;
  2
  3 import java.io.IOException;
  4 import java.util.ArrayList;
  5
  6 import javax.servlet.ServletException;
  7 import javax.servlet.annotation.WebServlet;
  8 import javax.servlet.http.HttpServlet;
  9 import javax.servlet.http.HttpServletRequest;
 10 import javax.servlet.http.HttpServletResponse;
 11
 12 import com.newjavaweb.User;
 13
 14 import Dao.userdao;
 15
 16 /**
 17  * Servlet implementation class Servlet
 18  */
 19 @WebServlet("/Servlet")
 20 public class Servlet extends HttpServlet {
 21     private static final long serialVersionUID = 1L;
 22
 23     /**
 24      * @see HttpServlet#HttpServlet()
 25      */
 26     public Servlet() {
 27         super();
 28         // TODO Auto-generated constructor stub
 29     }
 30
 31     /**
 32      * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
 33      */
 34     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 35         // TODO Auto-generated method stub
 36         request.setCharacterEncoding("utf-8");
 37         response.setContentType("textml;charset=utf-8");
 38
 39
 40
 41
 42         userdao dao=new userdao();
 43         java.util.List<User> list= new ArrayList<User>();
 44         String p[] = new String[5];//获得条件
 45         String s[] = new String[5];//获得内容
 46         String g[] = new String[5];//获得关系
 47         String f[] = new String[5];//获得精确或者模糊
 48         String number = null;
 49
 50         //String number1 = null;
 51         number=request.getParameter("number1");
 52         //number1=request.getParameter("number2");
 53         int n = Integer.parseInt(number);//接收条件的个数
 54         //int n1 = Integer.parseInt(number1);//   յĹ ϵ ĸ
 55         for(int i=1;i<=n;i++){
 56             p[i]= (String) request.getParameter("s"+i);
 57             s[i]=(String)request.getParameter("shuru"+i);
 58             f[i]=(String)request.getParameter("c"+i);
 59
 60             System.out.println("精确还是模糊   "+f[i]);
 61             System.out.println("条件   "+p[i]);
 62             System.out.println("输入    "+s[i]);
 63
 64             if(p[i].equals("学号")){
 65                 p[i] = "id";
 66             }
 67             else if(p[i].equals("姓名")){
 68                 p[i] = "name";
 69             }else if(p[i].equals("班级"))
 70             {
 71                 p[i] = "clas";
 72             }else if(p[i].equals("课程")){
 73                 p[i] = "ke";
 74             }else if(p[i].equals("分数")){
 75                 p[i] = "score";
 76             }
 77
 78
 79
 80         }
 81
 82         for(int i=1;i<n;i++){
 83             g[i]=(String) request.getParameter("g"+i);
 84             if(g[i].equals("且")) {
 85                 g[i]="and";
 86             }else if(g[i].equals("或")) {
 87                 g[i]="or";
 88             }
 89
 90             System.out.println("且或"+g[i]);
 91         }
 92
 93         String sql="where ";
 94         for(int i=1;i<n;i++){
 95             if(s[i].equals("")){
 96                 continue;
 97             }
 98             if(f[i].equals("精确")){
 99                 sql=sql+p[i]+"='"+s[i]+"'"+" "+g[i]+" ";
100             }else if(f[i].equals("模糊")){
101                 sql=sql+p[i]+" "+"LIKE"+" "+"'%"+s[i]+"%'"+" "+g[i]+" ";
102             }
103
104         }
105
106         if(f[n].equals("精确")) {
107             sql = sql + p[n]+"="+"'"+s[n]+"'";
108         }
109
110         else {
111             sql = sql + p[n]+" "+"LIKE"+" "+"'%"+s[n]+"%'";
112         }
113         if(n==1&&s[1].equals("")){
114             System.out.println("什么也没传！");
115             sql="";
116         }
117         list = dao.loadview(sql);
118
119             if(list.size()!=0) {
120             request.setAttribute("allthing",list);
121             request.setAttribute("message", "查询成功");
122             request.getRequestDispatcher("checkall.jsp").forward(request,response);
123             }
124             else {
125                 request.setAttribute("message", "查询失败");
126                 request.getRequestDispatcher("selectmore.jsp").forward(request,response);
127             }
128 //        HttpSession session = request.getSession();
129 //        session.setAttribute("tiaojian", list);
130 ////            int servletid=1;
131 ////            request.setAttribute("list", list);
132 ////            request.setAttribute("servletid", servletid);
133 //        try {
134 ////            request.getRequestDispatcher("/admin/123.jsp").forward(request, response);
135 //            response.sendRedirect(request.getContextPath()+"ow.jsp");
136 //        } catch (IOException e) {
137 //            // TODO  Զ    ɵ  catch
138 //            e.printStackTrace();
139 //        }
140
141
142     }
143
144     /**
145      * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
146      */
147     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
148         // TODO Auto-generated method stub
149         doGet(request, response);
150     }
151
152 }

//UserServlet类

  1 package servlet;
  2
  3 import java.io.IOException;
  4 import java.sql.ResultSet;
  5
  6 import javax.servlet.ServletException;
  7 import javax.servlet.annotation.WebServlet;
  8 import javax.servlet.http.HttpServlet;
  9 import javax.servlet.http.HttpServletRequest;
 10 import javax.servlet.http.HttpServletResponse;
 11 import javax.swing.JOptionPane;
 12
 13 import com.mysql.jdbc.Connection;
 14 import com.mysql.jdbc.Statement;
 15 import com.newjavaweb.User;
 16 import Dao.userdao;
 17 import util.DBUtil;
 18
 19 import java.util.List;
 20 /**
 21  * Servlet implementation class UserServlet
 22  */
 23 @WebServlet("/UserServlet")
 24 public class UserServlet extends HttpServlet {
 25     static String wen;
 26     private static final long serialVersionUID = 1L;
 27
 28     /**
 29      * @see HttpServlet#HttpServlet()
 30      */
 31     public UserServlet() {
 32         super();
 33         // TODO Auto-generated constructor stub
 34     }
 35     userdao dao = new userdao();
 36
 37     protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
 38         req.setCharacterEncoding("utf-8");
 39         String method = req.getParameter("method");
 40         if ("add".equals(method))
 41         {
 42             add(req, resp);
 43         }
 44         else if("search".equals(method))
 45         {
 46             search(req, resp);
 47         }
 48         else if("delete".equals(method))
 49         {
 50             delete(req,resp);
 51         }
 52         else if("allall".equals(method))
 53         {
 54             allall(req,resp);
 55         }
 56         else if("look".equals(method))
 57         {
 58             look(req,resp);
 59         }
 60         else if("update".equals(method))
 61         {
 62             update(req,resp);
 63         }
 64         else if("deletecheck".equals(method))
 65         {
 66             deletecheck(req,resp);
 67         }
 68         else if("paixu".equals(method))
 69         {
 70             paixu(req,resp);
 71         }
 72     }
 73
 74
 75     private void search(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
 76         // TODO Auto-generated method stub
 77         req.setCharacterEncoding("utf-8");
 78
 79         String zhanghu = req.getParameter("zhanghu");
 80         String psw = req.getParameter("psw");
 81         String rpassword = dao.search(zhanghu);
 82         String yanzheng1=req.getParameter("code");
 83         String yanzheng=(String)req.getSession().getAttribute("code");
 84
 85         if(!yanzheng1.equals(yanzheng))
 86         {
 87             req.setAttribute("message", "验证码错误");
 88             req.getRequestDispatcher("login.jsp").forward(req,resp);
 89         }
 90
 91         if(psw.equals(rpassword)) {
 92             //JOptionPane.showMessageDialog(null,"登陆成功！");
 93             req.setAttribute("message", "登陆成功！");
 94             req.getRequestDispatcher("NewFile.jsp").forward(req,resp);
 95         }
 96         else {
 97             //JOptionPane.showMessageDialog(null,"账号不存在或密码错误！");
 98             req.setAttribute("message", "账号不存在或密码错误！");
 99             req.getRequestDispatcher("login.jsp").forward(req,resp);
100         }
101     }
102     private void add(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
103         // TODO Auto-generated method stub
104         String id=req.getParameter("id");
105         String name=req.getParameter("name");
106         String clas=req.getParameter("clas");
107         String ke=req.getParameter("ke");
108         String score=req.getParameter("score");
109
110         User user= new User(id,name,clas,ke,score);
111
112         String rusername = dao.find(name);
113
114         if(!name.equals(rusername)) {
115             dao.add(user);
116
117             req.setAttribute("message", "添加成功!");
118             req.getRequestDispatcher("UserServlet?method=allall").forward(req, resp);
119         }else {
120
121             req.setAttribute("message", "账户重复，请重新输入!");
122             req.getRequestDispatcher("zc.jsp").forward(req, resp);
123         }
124     }
125
126     private void deletecheck(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException
127     {
128         req.setCharacterEncoding("utf-8");
129         String name =req.getParameter("name4");
130         String rusername = dao.find(name);
131         if(!name.equals(rusername))
132         {
133             req.setAttribute("message", "用户不存在请重新输入");
134             req.getRequestDispatcher("delete.jsp").forward(req, resp);
135             return;
136         }
137         List<User> Thething1 =dao.examine(name);
138         req.setAttribute("Thething1", Thething1);
139         req.getRequestDispatcher("deletecheck2.jsp").forward(req, resp);
140     }
141
142     private void delete(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
143              req.setCharacterEncoding("utf-8");
144              String name=req.getParameter("name");
145              boolean wen=dao.delete(name);
146              if(wen)
147              {
148                  req.setAttribute("message", "删除成功！");
149                  req.getRequestDispatcher("delete1.jsp").forward(req,resp);
150              }
151              else
152              {
153                  req.setAttribute("message", "此用户不存在，删除失败");
154                  req.getRequestDispatcher("delete.jsp").forward(req,resp);
155              }
156
157           }
158
159
160     private void paixu(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException
161     {
162         req.setCharacterEncoding("utf-8");
163         List<User> allthing =dao.paixu();
164         req.setAttribute("allthing", allthing);
165         req.getRequestDispatcher("checkall.jsp").forward(req, resp);
166     }
167     private void allall(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException
168     {
169          req.setCharacterEncoding("utf-8");
170          List<User> allthing = dao.theall();
171          req.setAttribute("allthing", allthing);
172          req.getRequestDispatcher("checkall.jsp").forward(req,resp);
173     }
174     private void look(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException
175     {
176         req.setCharacterEncoding("utf-8");
177         String name5 = req.getParameter("name5");
178         wen=name5;
179         String q1=dao.find(name5);
180         if(q1.equals("@"))
181         {
182             req.setAttribute("message", "此用户不存在，不能进行修改");
183             req.getRequestDispatcher("updatesome.jsp").forward(req,resp);
184             return;
185         }
186         User user3 = dao.getUserbyzhanghu(name5);
187         req.setAttribute("user3", user3);
188         req.getRequestDispatcher("updatesome1.jsp").forward(req,resp);
189     }
190
191     private void update(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException
192     {
193         req.setCharacterEncoding("utf-8");
194         String id=req.getParameter("id6");
195         String name = req.getParameter("name6");
196         String clas=req.getParameter("clas6");
197         String ke=req.getParameter("ke6");
198         String score=req.getParameter("score6");
199
200         User user= new  User(id,name,clas,ke,score);
201         dao.update(user,name);
202         req.setAttribute("message", "修改成功");
203         req.getRequestDispatcher("updatesome2.jsp").forward(req,resp);
204     }
205 }

//DBUtil类

 1 package util;
 2
 3 //数据库连接
 4 import java.sql.Connection;
 5 import java.sql.DriverManager;
 6 import java.sql.ResultSet;
 7 import java.sql.SQLException;
 8 import java.sql.Statement;
 9
10 /**
11 * 数据库连接工具
12 * @author Zheng
13 *
14 */
15 public class DBUtil {
16
17     public static String db_url = "jdbc:mysql://localhost:3306/student?useSSL=false";
18     public static String db_user = "root";
19     public static String db_pass = "001206";
20
21     public static Connection getConn () {
22         Connection conn = null;
23
24         try {
25             Class.forName("com.mysql.jdbc.Driver");//加载驱动
26             conn = DriverManager.getConnection(db_url, db_user, db_pass);//通过输入的用户名还有密码来建立一个到数据库的连接主要是调用connect（）方法
27         } catch (Exception e) {
28             e.printStackTrace();
29         }
30
31         return conn;
32     }
33
34     /**
35      * 关闭连接
36      * @param state
37      * @param conn
38      */
39     public static void close (Statement state, Connection conn) {
40         if (state != null) {
41             try {
42                 state.close();
43             } catch (SQLException e) {
44                 e.printStackTrace();
45             }
46         }
47
48         if (conn != null) {
49             try {
50                 conn.close();
51             } catch (SQLException e) {
52                 e.printStackTrace();
53             }
54         }
55     }
56
57     public static void close (ResultSet rs, Statement state, Connection conn) {
58         if (rs != null) {
59             try {
60                 rs.close();
61             } catch (SQLException e) {
62                 e.printStackTrace();
63             }
64         }
65
66         if (state != null) {
67             try {
68                 state.close();
69             } catch (SQLException e) {
70                 e.printStackTrace();
71             }
72         }
73
74         if (conn != null) {
75             try {
76                 conn.close();
77             } catch (SQLException e) {
78                 e.printStackTrace();
79             }
80         }
81     }
82
83 }

//TheMain.jsp

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html>
 4 <html>
 5 <head>
 6 <meta charset="UTF-8">
 7 <title>主页</title>
 8 </head>
 9 <style>
10 a:link    {color:blue;}
11 a:visited {color:blue;}/*选择未访问、已访问、悬浮和活动链接，并设置它们的样式：*/
12 a:hover   {color:red;}
13 a{
14    font-size:22px;
15    font-family:"楷体";/*设置字体*/
16    font-weight:2px;
17  }
18 h1 {
19     color:red;
20     font-size:44px;
21 }
22 </style>
23 <body >
24 <%
25          Object message = request.getAttribute("message");//放置一个字符串，并取出
26          if(message!=null && !"".equals(message)){
27
28     %>
29          <script type="text/javascript">
30               alert("<%=request.getAttribute("message")%>");
31               request.setAttribute("message", "");
32          </script>
33     <%} %>
34 <h1 align="center" >请选择下面其中一项</h1>
35 <a href="UserServlet?method=allall" style="text-decoration:none" ><h2 align="center">显示全部学生信息</h2></a>
36
37 <a href="zc.jsp" style="text-decoration:none" ><h2 align="center">增加学生信息</h2></a>
38
39 <a href="delete.jsp" style="text-decoration:none" ><h2 align="center">删除学生信息</h2></a>
40
41 <a href="updatesome.jsp" style="text-decoration:none" ><h2 align="center">修改学生信息</h2></a>
42
43 <a href="selectmore.jsp" style="text-decoration:none" ><h2 align="center">查找学生信息</h2></a>
44
45 <a href="UserServlet?method=paixu" style="text-decoration:none" ><h2 align="center">成绩排序</h2></a>
46 </body>
47 </html>

//checkall.jsp

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
 4 <!DOCTYPE html>
 5 <html>
 6 <head>
 7 <meta charset="UTF-8">
 8 <title>全部信息</title>
 9 </head>
10 <body  >
11
12  <div align="center">
13         <h1 style="color: red;" align="center"> 所有成员信息列表</h1>
14         <table border="1px" cellspacing="0" cellpadding="5px">
15              <tr height="35px">
16                  <td><h3 style="color: yellow;">学号</h3></td>
17                  <td><h3 style="color: yellow;">姓名</h3></td>
18                  <td><h3 style="color: yellow;">班级</h3></td>
19                  <td><h3 style="color: yellow;">课程</h3></td>
20                  <td><h3 style="color: yellow;">分数</h3></td>
21              </tr>
22              <tr height="35px">
23              <c:forEach items="${allthing}" var="item" >
24                  <td>${item.id }</td>
25                  <td>${item.name }</td>
26                  <td>${item.clas }</td>
27                  <td>${item.ke }</td>
28                  <td>${item.score }</td>
29
30                  </tr>
31              </c:forEach>
32         </table>
33                 <a href="TheMain.jsp"><h2 align="center">点击此处返回主页面</h2></a>
34     </div>
35 </body>
36 </html>

//delete.jsp

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html>
 4 <html>
 5 <head>
 6 <meta charset="UTF-8">
 7 <title>删除学生信息</title>
 8 </head>
 9 <body  text="yellow" style="background: url(images/wen7.jpg); background-size:100%" >
10 <h2 align="center">请输入想要删除信息的用户名</h2>
11 <form   action="UserServlet?method=deletecheck"  onsubmit="return chackall()"  method="post"  >
12
13 <%
14          Object message = request.getAttribute("message");//放置一个字符串，并取出
15          if(message!=null && !"".equals(message)){
16
17     %>
18          <script type="text/javascript">
19               alert("<%=request.getAttribute("message")%>");
20          </script>
21     <%} %>
22
23 <table align="center">
24 <tr><td>名字：</td>
25 <td><input type="text" id="name4" name="name4" style=" border-color:Lime;border-radius:6px;" maxlength="12" value="" placeholder="请输入账户名"  /></td>
26 <tr><td></td><td>
27 <input type="submit" value="删除此用户所有信息"  style="background-color:CornflowerBlue;width:150px;height:25px;border-radius:4px;" ></td>
28 <a href="TheMain.jsp"><h3 align="center">点击此处回到主页面!!!!!!</h4></a>
29 <script type="text/javascript">
30
31         //重置按钮处添加onclick调用formReset %>
32         function checkZhanghao()
33         {
34             var zhanghao = document.getElementById("zhanghu4");
35             var zhanghao1=zhanghao.value;
36             var reg = /^[a-z][a-z0-9A-Z]{6}/;
37             var ref= /^[A-Z][a-z0-9A-Z]{6}/
38             if(reg.test(zhanghao1)||ref.test(zhanghao1)){
39                 //符合规则
40                 return true;
41             }else{
42                 //不符合规则
43                 alert('账户格式错误,应以英文字母开头并且7位及以上');
44                 zhanghao.value = "";
45                  zhanghao.focus();
46                 return false;
47             }
48         }
49         function chackall() {
50             var zhanghu3=document.getElementById("zhanghu4");
51             if(zhanghu3.value=="")
52             {
53                alert("用户名不能为空");
54                zhanghu3.focus();
55                return false;
56             }
57             return true;
58         }
59       </script>
60
61 </table>
62 </form>
63 </body>
64 </html>

//delete1.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body  text="yellow" style="background: url(images/wen5.jpg); background-size:100%">
<%
         Object message = request.getAttribute("message");//放置一个字符串，并取出
         if(message!=null && !"".equals(message)){

    %>
         <script type="text/javascript">
              alert("<%=request.getAttribute("message")%>");
         </script>
    <%} %>
    <h2 align="center">恭喜您删除消息成功!!!!!</h2>
    <a href="TheMain.jsp"><h2 align="center">点击此处返回到主页面</h2></a>
</body>
</html>

//deletecheck2.jsp

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
 4 <%@ taglib uri="http://java.sun.com/jsp/jstl/functions"  prefix="fn"%>
 5 <!DOCTYPE html>
 6 <html>
 7 <head>
 8 <meta charset="UTF-8">
 9 <title>再次确定删除</title>
10 </head>
11 <style>
12 a:link    {color:blue;}
13 a:visited {color:blue;}/*选择未访问、已访问、悬浮和活动链接，并设置它们的样式：*/
14 a:hover   {color:red;}
15 a{
16    font-size:18px;
17    font-family:"楷体";/*设置字体*/
18    font-weight:2px;
19  }
20 h1{
21     color:red;
22     font-size:44px;
23 }
24 </style>
25 <body text="red" >
26 <div align="center">
27         <h1 style="color: red;" align="center"> 所有成员信息列表</h1>
28         <table width="900">
29              <tr>
30               <tr height="35px">
31                  <td><h3 style="color: yellow;">学号</h3></td>
32                  <td><h3 style="color: yellow;">姓名</h3></td>
33                  <td><h3 style="color: yellow;">班级</h3></td>
34                  <td><h3 style="color: yellow;">课程</h3></td>
35                  <td><h3 style="color: yellow;">分数</h3></td>
36              </tr>
37              <tr height="35px">
38              <c:forEach items="${Thething1 }" var="item" >
39                  <td>${item.id }</td>
40                  <td>${item.name }</td>
41                  <td>${item.clas }</td>
42                  <td>${item.ke }</td>
43                  <td>${item.score }</td>
44
45                  <td><a href="UserServlet?method=delete&name=${item.name }" onclick="return check()">删除</a>
46
47                  </c:forEach>
48              </tr>
49
50
51         </table>
52          <script type="text/javascript">
53           function check() {
54             if (confirm("真的要删除吗？")){
55                 return true;
56             }else{
57                 return false;
58             }
59           }
60           </script>
61
62                 <a href="TheMain.jsp"><h2 align="center">点击此处返回主页面</h2></a>
63 </html>

//paixu.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>成绩排序结果</title>
</head>
<body>
<div align="center">
        <h1 style="color: red;" align="center"> 所有成员信息列表</h1>
        <table border="1px" cellspacing="0" cellpadding="5px">
             <tr height="35px">
                 <td><h3 style="color: yellow;">学号</h3></td>
                 <td><h3 style="color: yellow;">姓名</h3></td>
                 <td><h3 style="color: yellow;">班级</h3></td>
                 <td><h3 style="color: yellow;">课程</h3></td>
                 <td><h3 style="color: yellow;">分数</h3></td>
             </tr>
             <tr height="35px">
             <c:forEach items="${things}" var="item" >
                 <td>${item.id }</td>
                 <td>${item.name }</td>
                 <td>${item.clas }</td>
                 <td>${item.ke }</td>
                 <td>${item.score }</td>

                 </tr>
             </c:forEach>
        </table>
                <a href="TheMain.jsp"><h2 align="center">点击此处返回主页面</h2></a>
    </div>
</body>
</html>

//selectmore.jsp

  1 <%@ page language="java" contentType="text/html; charset=UTF-8"
  2     pageEncoding="UTF-8"%>
  3 <!DOCTYPE html>
  4 <html>
  5 <head>
  6 <meta charset="UTF-8">
  7 <title>查找学生信息</title>
  8
  9 <script>
 10 var i=1;
 11 var j=1;
 12 document.getElementById('number1').value=i;
 13 document.getElementById('number2').value=j;
 14 function demoDisplay(){
 15     if(document.getElementById("p2").style.display=="none"){
 16         i++;
 17         j++;
 18         document.getElementById("p2").style.display="inline";
 19         document.getElementById('number1').value=i;
 20         document.getElementById('number2').value=j;
 21 //         alert(i);
 22 //         alert(j);
 23         return;
 24     }else if(document.getElementById("p3").style.display=="none")
 25         {
 26             i++;
 27             j++;
 28             document.getElementById("p3").style.display="inline";
 29             document.getElementById('number1').value=i;
 30             document.getElementById('number2').value=j;
 31 //             alert(i);
 32 //             alert(j);
 33             return;
 34         }else if(document.getElementById("p4").style.display=="none")
 35         {
 36             i++;
 37             j++;
 38             document.getElementById("p4").style.display="inline";
 39             document.getElementById('number1').value=i;
 40             document.getElementById('number2').value=j;
 41 //             alert(i);
 42 //             alert(j);
 43             return;
 44         }else if(document.getElementById("p5").style.display=="none")
 45         {
 46             i++;
 47             j++;
 48             document.getElementById("p5").style.display="inline";
 49             document.getElementById('number1').value=i;
 50             document.getElementById('number2').value=j;
 51 //             alert(i);
 52 //             alert(j);
 53             return;
 54         }
 55 }
 56 function demoVisibility(){
 57     if(document.getElementById("p5").style.display=="inline")
 58     {
 59         i--;
 60         j--;
 61         document.getElementById("p5").style.display="none";
 62         document.getElementById('number1').value=i;
 63         document.getElementById('number2').value=j;
 64         //System.out.println("i:"+i+"j"+j);
 65         return;
 66     }else if(document.getElementById("p4").style.display=="inline")
 67     {
 68         i--;
 69         j--;
 70         document.getElementById("p4").style.display="none";
 71         document.getElementById('number1').value=i;
 72         document.getElementById('number2').value=j;
 73         //System.out.println("i:"+i+"j"+j);
 74         return;
 75     }else if(document.getElementById("p3").style.display=="inline")
 76     {
 77         i--;
 78         j--;
 79         document.getElementById("p3").style.display="none";
 80         document.getElementById('number1').value=i;
 81         document.getElementById('number2').value=j;
 82         //System.out.println("i:"+i+"j"+j);
 83         return;
 84     }else if(document.getElementById("p2").style.display=="inline")
 85     {
 86         i--;
 87         j--;
 88         document.getElementById("p2").style.display="none";
 89         document.getElementById('number1').value=i;
 90         document.getElementById('number2').value=j;
 91         //System.out.println("i:"+i+"j"+j);
 92         return;
 93     }
 94 }
 95 </script>
 96
 97 </head>
 98 <body>
 99 <%
100     Object message=request.getAttribute("message");
101     if(message!=null&&!"".equals(message)){
102         %>
103
104     <script type="text/javascript">
105         alert("<%=request.getAttribute("message")%>");
106     </script>
107  <%}%>
108 <form  action="Servlet" method="post">
109 <br>
110 &nbsp;&nbsp;
111 <button type="button" onclick="demoDisplay()" class="layui-btn layui-btn-primary layui-btn-sm"><i class="layui-icon">+</i></button>
112 <button type="button" onclick="demoVisibility()" class="layui-btn layui-btn-primary layui-btn-sm"><i class="layui-icon">-</i></button><br>
113
114 &nbsp;&nbsp;
115 <div id="p1">
116 &nbsp;&nbsp;
117     <select name="g22" style="visibility:hidden">
118     <option value="且">且</option>
119     <option value="或">或</option>
120     </select>
121     <select name="s1" >
122     <option>学号</option>
123     <option>姓名</option>
124     <option>班级</option>
125     <option>课程</option>
126     <option>分数</option>
127     </select>
128     <input type="text" name="shuru1" value="" />
129     <select name="c1">
130     <option>精确</option>
131     <option>模糊</option>
132     </select>
133     <br>
134 </div>
135
136 <div id="p2" style="display:none">
137 &nbsp;&nbsp;
138     <select name="g1" >
139     <option value="且">且</option>
140     <option value="或">或</option>
141     </select>
142     <select name="s2">
143     <option>学号</option>
144     <option>姓名</option>
145     <option>班级</option>
146     <option>课程</option>
147     <option>分数</option>
148     </select>
149     <input type="text" name="shuru2" value="" />
150     <select name="c2">
151     <option>精确</option>
152     <option>模糊</option>
153     </select>
154     <br>
155 </div>
156
157 <div id="p3" style="display:none">
158 &nbsp;&nbsp;
159 <select name="g2">
160     <option value="且">且</option>
161     <option value="或">或</option>
162     </select>
163     <select name="s3">
164     <option>学号</option>
165     <option>姓名</option>
166     <option>班级</option>
167     <option>课程</option>
168     <option>分数</option>
169     </select>
170     <input type="text" name="shuru3" value="" />
171     <select name="c3">
172     <option>精确</option>
173     <option>模糊</option>
174     </select>
175     <br>
176 </div>
177
178 <div id="p4" style="display:none">
179 &nbsp;&nbsp;
180 <select name="g3">
181     <option value="且">且</option>
182     <option value="或">或</option>
183     </select>
184     <select name="s4">
185     <option>学号</option>
186     <option>姓名</option>
187     <option>班级</option>
188     <option>课程</option>
189     <option>分数</option>
190     </select>
191     <input type="text" name="shuru4" value="" />
192     <select name="c4">
193     <option>精确</option>
194     <option>模糊</option>
195     </select>
196     <br>
197 </div>
198
199 <div id="p5" style="display:none">
200 &nbsp;&nbsp;
201 <select name="g4">
202     <option value="且">且</option>
203     <option value="或">或</option>
204     </select>
205     <select name="s5">
206     <option>学号</option>
207     <option>姓名</option>
208     <option>班级</option>
209     <option>课程</option>
210     <option>分数</option>
211     </select>
212     <input type="text" name="shuru5" value="" />
213     <select name="c5">
214     <option>精确</option>
215     <option>模糊</option>
216     </select>
217 </div>
218 <p hidden>
219 <input type="text" value="1" id="number1" name="number1">
220 <input type="text" value="1" id="number2" name="number2">
221 </p>
222 <br>
223     <input type="submit" name="submit" value="查询" >
224   </form>
225   <br>
226 <h4 align="left">
227 <%--  一共查询到了<span style="color:red"><%=list.size() %></span>条数据  --%>
228 </h4>
229 <table class="table table-striped">
230 <a href="TheMain.jsp"><h3 align="left">点击此处回到主页面!!!!!!</h4></a>
231  </table>
232
233 </body>
234 </html>

//updatesome.jsp

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html>
 4 <html>
 5 <head>
 6 <meta charset="UTF-8">
 7 <title>修改学生信息</title>
 8 </head>
 9 <body  >
10 <h2 align="center">请输入想要修改信息的用户名</h2>
11 <form   action="UserServlet?method=look"  onsubmit="return chackall()"  method="post"  >
12
13 <%
14          Object message = request.getAttribute("message");//放置一个字符串，并取出
15          if(message!=null && !"".equals(message)){
16
17     %>
18          <script type="text/javascript">
19               alert("<%=request.getAttribute("message")%>");
20          </script>
21     <%} %>
22
23 <table align="center">
24 <tr><td>姓名：</td><td><input type="text" id="name5" style=" border-color:Lime;border-radius:6px;" name="name5" maxlength="12" value="" placeholder="请输入账户名"  /></td>
25 <tr><td></td><td><input type="submit" value="进行修改" style="background-color:CornflowerBlue;width:150px;height:25px;border-radius:4px;" ></td>
26 <a href="TheMain.jsp"><h3 align="center">点击此处回到主页面!!!!!!</h4></a>
27 <script type="text/javascript">
28
29         //重置按钮处添加onclick调用formReset %>
30         function checkZhanghao()
31         {
32             var zhanghao = document.getElementById("zhanghu3");
33             var zhanghao1=zhanghao.value;
34             var reg = /^[a-z][a-z0-9A-Z]{6}/;
35             var ref= /^[A-Z][a-z0-9A-Z]{6}/
36             if(reg.test(zhanghao1)||ref.test(zhanghao1)){
37                 //符合规则
38                 return true;
39             }else{
40                 //不符合规则
41                 alert('账户格式错误,应以英文字母开头并且7位及以上');
42                 zhanghao.value = "";
43                  zhanghao.focus();
44                 return false;
45             }
46         }
47         function chackall() {
48         var zhanghu3=document.getElementById("zhanghu3");
49         if(zhanghu3.value=="")
50         {
51            alert("用户名不能为空");
52            zhanghu3.focus();
53            return false;
54         }
55         return true;
56         }
57       </script>
58
59 </table>
60 </form>
61 </body>
62 </html>

//updatesome1.jsp

  1 <%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
  2 <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
  3 <%@ taglib uri="http://java.sun.com/jsp/jstl/functions"  prefix="fn"%>
  4 <!DOCTYPE html>
  5 <html>
  6 <head>
  7 <meta charset="utf-8">
  8 <title>再次确认修改</title>
  9 </head>
 10 <body  >
 11 <form action="UserServlet?method=update"  method="post"  onsubmit="return chackall()" >
 12 <%
 13          Object message = request.getAttribute("message");//放置一个字符串，并取出
 14          if(message!=null && !"".equals(message)){
 15
 16     %>
 17          <script type="text/javascript">
 18               alert("<%=request.getAttribute("message")%>");
 19          </script>
 20     <%} %>
 21
 22     学号：<input type="text" id="id6" name="id6" style=" border-color:Lime;border-radius:6px;"  maxlength="12" required="required"/><br><br>
 23     姓名：<input type="text" id="name6" name="name6" style=" border-color:Lime;border-radius:6px;" value="${user3.name}" maxlength="12"   /><br><br>
 24            班级：<input type="text" id="clas6" name="clas6" style=" border-color:Lime;border-radius:6px;" maxlength="12" required="required"  /><br><br>
 25            课程：<input type="text" id="ke6" name="ke6" style=" border-color:Lime;border-radius:6px;" maxlength="12" required="required"  /><br><br>
 26            分数：<input type="text" id="score6" name="score6" style=" border-color:Lime;border-radius:6px;" maxlength="12" required="required"  /><br><br>
 27
 28     <hr>
 29
 30     <input type="submit" value="确认修改">
 31
 32
 33 <br/>
 34 <br/>
 35
 36 <script type="text/javascript">
 37         //重置按钮处添加onclick调用formReset %>
 38          var num=0;
 39
 40        function doCheck(ctrl) {
 41            if(ctrl.checked){
 42            num++;
 43            //window.alert("iNumChecked++" + iNumChecked);
 44            } else {
 45            num--;
 46            //window.alert("iNumChecked--" + iNumChecked);
 47            }
 48            if (num> 4) {
 49            ctrl.checked = false;
 50            num--;
 51            window.alert('最多可以选择六组进行比较');
 52            }
 53            }
 54
 55         function checkZhanghao()
 56         {
 57             var zhanghao = document.getElementById("zhanghu");
 58             var zhanghao1=zhanghao.value;
 59             var reg = /^[a-z][a-z0-9A-Z]{6}/;
 60             var ref= /^[A-Z][a-z0-9A-Z]{6}/
 61             if(reg.test(zhanghao1)||ref.test(zhanghao1)){
 62                 //符合规则
 63                 return true;
 64             }else{
 65                 //不符合规则
 66                 alert('账户格式错误,应以英文字母开头并且7位及以上');
 67                 zhanghao.value = "";
 68                  zhanghao.focus();
 69                 return false;
 70             }
 71         }
 72
 73         function checkPassword()
 74         {
 75             var password = document.getElementById("psw");
 76             if((password.value).length<8)
 77             {
 78                 alert('密码应为8位英文或数字');
 79                 password.value="";
 80                 password.focus();
 81                 return false;
 82             }
 83         }
 84
 85         function checkId()
 86         {
 87             var id1 = document.getElementById("xuehao")
 88             var id=id1.value;
 89             //学号的正确形式
 90            // var reg = /^[0-9a-zA-Z]{6}/;
 91             if((id<"20180000")|| (id>"20189999"))
 92             {
 93                 alert('学号格式不正确应以2018开头的八位数字，请重新填写！');
 94                 id1.value="";
 95                 id1.focus();
 96                 return false;
 97             }
 98             else{
 99                 //不符合规则
100                 return true;
101             }
102         }
103
104
105     </script>
106
107
108
109        <script type="text/javascript">
110         function chackall() {
111         var sex=document.getElementById("sex");
112         var xueyuan=document.getElementById("xueyuan");
113         var name=document.getElementById("name");
114         var xi=document.getElementById("xi");
115         var class1=document.getElementById("class1");
116         var year=document.getElementById("year");
117         var sheng=document.getElementById("sheng");
118         var beizhu=document.getElementById("beizhu");
119         var mail=document.getElementById("mail");
120
121         if(sex.value=="")
122         {
123          alert("性别不能为空");
124          sex.focus();
125          return false;
126         }
127
128         if(name.value=="")
129         {
130         alert("名字不能为空");
131          name.focus();
132          return false;
133         }
134
135
136         if(mail.value=="")
137         {
138         alert("邮箱不能为空");
139          n.focus();
140          return false;
141         }
142
143         if(xueyuan.value=="")
144         {
145         alert("所在学院不能为空");
146          xueyuan.focus();
147          return false;
148         }
149
150         if(xi.value=="")
151         {
152         alert("所在系不能为空");
153          xi.focus();
154          return false;
155         }
156
157         if(class1.value=="")
158         {
159         alert("所在班级不能为空");
160          class1.focus();
161          return false;
162         }
163
164         if(year.value=="")
165         {
166         alert("入学年份不能为空");
167          year.focus();
168          return false;
169         }
170
171         if(sheng.value=="")
172         {
173         alert("生源地不能为空");
174          sheng.focus();
175          return false;
176         }
177
178         if(beizhu.value=="")
179         {
180         alert("备注不能为空");
181          beizhu.focus();
182          return false;
183         }
184
185
186         }
187
188       </script>
189 </form>
190 </body>
191 </html>

//updatesome2.jsp

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html>
 4 <html>
 5 <head>
 6 <meta charset="UTF-8">
 7 <title>修改信息成功</title>
 8 </head>
 9 <body  style="background: url(images/wen7.jpg); background-size:100%" text="yellow">
10 <%
11          Object message = request.getAttribute("message");//放置一个字符串，并取出
12          if(message!=null && !"".equals(message)){
13
14     %>
15          <script type="text/javascript">
16               alert("<%=request.getAttribute("message")%>");
17          </script>
18     <%} %>
19     <h2 align="center">恭喜您修改信息成功！！！！！</h2>
20     <h2 align="center"><a href="TheMain.jsp">点击此处回到主页面</a></h2>
21 </body>
22 </html>

//zc.jsp

  1 <%@ page language="java" contentType="text/html; charset=utf-8"
  2     pageEncoding="utf-8"%>
  3 <!DOCTYPE html>
  4 <html>
  5 <head>
  6 <meta charset="utf-8">
  7 <title>增加学生信息</title>
  8 <style>
  9 h3{
 10     color:red;
 11     font-size:15px;
 12 }
 13 </style>
 14 </head>
 15 <body    >
 16 <%--onsubmit="return chackall()" --%>
 17 <form action="UserServlet?method=add"  method="post"  onsubmit="return chackall()" >
 18 <%
 19          Object message = request.getAttribute("message");//放置一个字符串，并取出
 20          if(message!=null && !"".equals(message)){
 21
 22     %>
 23          <script type="text/javascript">
 24               alert("<%=request.getAttribute("message")%>");
 25          </script>
 26     <%} %>
 27        学号：<input type="text" id="id" name="id" style=" border-color:Lime;border-radius:6px;" maxlength="12" required="required"  /><br><br>
 28            姓名：<input type="text" id="name" name="name" style=" border-color:Lime;border-radius:6px;" maxlength="12" required="required"  /><br><br>
 29            班级：<input type="text" id="clas" name="clas" style=" border-color:Lime;border-radius:6px;" maxlength="12" required="required"  /><br><br>
 30            课程：<input type="text" id="ke" name="ke" style=" border-color:Lime;border-radius:6px;" maxlength="12" required="required"  /><br><br>
 31            分数：<input type="text" id="score" name="score" style=" border-color:Lime;border-radius:6px;" maxlength="12" required="required"  /><br><br>
 32     <hr>
 33     <input type="submit" value="添加">
 34
 35     <a href="TheMain.jsp"><h3 align="left">点击此处回到主页面!!!!!!</h4></a>
 36 <br/>
 37 <br/>
 38 <%--
 39 <script type="text/javascript">
 40         //重置按钮处添加onclick调用formReset %>
 41
 42         function checkZhanghao()
 43         {
 44             var zhanghao = document.getElementById("zhanghu");
 45             var zhanghao1=zhanghao.value;
 46             var reg = /^[a-z][a-z0-9A-Z]{6}/;
 47             var ref= /^[A-Z][a-z0-9A-Z]{6}/
 48             if(reg.test(zhanghao1)||ref.test(zhanghao1)){
 49                 //符合规则
 50                 return true;
 51             }else{
 52                 //不符合规则
 53                 alert('账户格式错误,应以英文字母开头并且7位及以上');
 54                 zhanghao.value = "";
 55                  zhanghao.focus();
 56                 return false;
 57             }
 58         }
 59
 60         function checkPassword()
 61         {
 62             var password = document.getElementById("psw");
 63             if((password.value).length<8)
 64             {
 65                 alert('密码应为8位英文或数字');
 66                 password.value="";
 67                 password.focus();
 68                 return false;
 69             }
 70         }
 71
 72         function checkId()
 73         {
 74             var id1 = document.getElementById("xuehao")
 75             var id=id1.value;
 76             //学号的正确形式
 77            // var reg = /^[0-9a-zA-Z]{6}/;
 78             if((id<"20180000")|| (id>"20189999"))
 79             {
 80                 alert('学号格式不正确应以2018开头的八位数字，请重新填写！');
 81                 id1.value="";
 82                 id1.focus();
 83                 return false;
 84             }
 85             else{
 86                 //不符合规则
 87                 return true;
 88             }
 89         }
 90
 91
 92     </script>--%>
 93
 94
 95
 96        <script type="text/javascript">
 97        var num=0;
 98
 99
100        function doCheck(ctrl) {
101                if(ctrl.checked)
102               {
103                num++;
104               }
105               else
106               {
107                    num--;
108               }
109            if (num> 4)
110            {
111                 ctrl.checked = false;
112                  num--;
113                  window.alert('最多可以选择4组进行比较');
114            }
115     }
116
117
118
119
120
121
122             <%--
123         var name=document.getElementById("name");
124         var sex=document.getElementById("sex");
125         var minzu=document.getElementById("minzu");
126         var time=document.getElementById("time");
127         var age=document.getElementById("age");
128         var zhengzhi=document.getElementById("zhengzhi");
129         var fuwu=document.getElementById("fuwu");
130
131         if(name.value=="")
132         {
133          alert("名字不能为空");
134          name.focus();
135          return false;
136         }
137
138         if(sex.value=="")
139         {
140         alert("性别不能为空");
141          sex.focus();
142          return false;
143         }
144
145
146         if(minzu.value=="")
147         {
148         alert("民族不能为空");
149          minzu.focus();
150          return false;
151         }
152
153         if(time.value=="")
154         {
155         alert("时间不能为空");
156          time.focus();
157          return false;
158         }
159
160         if(age.value=="")
161         {
162         alert("年龄不能为空");
163          age.focus();
164          return false;
165         }
166
167         if(zhengzhi.value=="")
168         {
169         alert("政治面目不能为空");
170          zhengzhi.focus();
171          return false;
172         }
173         if(fuwu.value=="")
174         {
175         alert("服务不能为空");
176          fuwu.focus();
177          return false;
178         }
179         --%>
180         function chackall() {
181                 var a=document.getElementsByName('fuwu');
182                 var b=0;     //设定一个初始值
183                 for(var i=0;i<a.length;i++)
184                 {
185
186                     if(a[i].checked==true)
187                     {
188                         return true;
189                     }
190                     else
191                     {
192                         if(a[i].checked==false)
193                         {
194                             b++;    //如果方框没选中，该值会累加
195                         }
196                         if(b==a.length)   //如果该值和方框的个数相同，那么就会报错
197                         {
198                             alert('服务类型最少选一个，最多选四个,请重新操作');
199                             return false;
200                         }
201                     }
202                 }
203             }
204
205
206
207
208       </script>
209 </form>
210
211 </body>
212 </html>

//zc2.jsp

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html>
 4 <html>
 5 <head>
 6 <meta charset="UTF-8">
 7 <title>添加用户成功</title>
 8 </head>
 9 <body  style="background: url(images/wen7.jpg); background-size:100%" text="yellow">
10 <h2 align="center">恭喜您添加用户成功</h2>
11 <a href="zc.jsp"><h3 align="center">点击此处回到添加页面!!!!!!</h4></a>
12 <a href="Themain.jsp"><h3 align="center">点击此处回到主页面!!!!!!</h4></a>
13 </body>
14 </html>

3、感谢你的观看，有什么问题或者不懂的请你评论在下方，或者联系我，会很耐心的为你解答。我们一起加油！！！！