JDBC MySQL 实例之 用户管理系统

  1 package day01;
  2 
  3 import java.sql.Connection;
  4 import java.sql.DriverManager;
  5 import java.sql.ResultSet;
  6 import java.sql.SQLException;
  7 import java.sql.Statement;
  8 import java.util.ArrayList;
  9 import java.util.List;
 10 import java.util.Scanner;
 11 
 12 /**
 13  * 用户登录系统
 14  * Description: 
 15  */
 16 public class Service {
 17     private static final int USER_REG = 1;
 18     private static final int USER_LOGIN = USER_REG + 1;
 19     private static final int USER_UPDATE = USER_LOGIN + 1;
 20     private static final int USER_DELETE = USER_UPDATE + 1;
 21     private static final int USER_INFO = USER_DELETE + 1;
 22     private static final int USER_TRANSFER = USER_INFO + 1;
 23     private static final int USER_QUIT = USER_TRANSFER + 1;
 24     private static final int EXIT = USER_QUIT + 1;
 25     
 26     UserInfo user = null;
 27     
 28     public static void main(String[] args) {
 29         Service serv = new Service();
 30         serv.start();
 31     }
 32     
 33     private void start() {
 34         welcome();
 35         int code = getCode();
 36         execute(code);
 37     }
 38 
 39     /**
 40      * 执行选择
 41      * Description: 
 42      */
 43     private void execute(int code) {
 44         switch (code) {
 45         case USER_REG:
 46             user_reg();
 47             break;
 48         case USER_LOGIN:
 49             user_login();
 50             break;
 51         case USER_UPDATE:
 52             user_update();
 53             break;
 54         case USER_DELETE:
 55             user_delete();
 56             break;
 57         case USER_INFO:
 58             user_info();
 59             break;
 60         case USER_TRANSFER:
 61             user_transfer();
 62             break;
 63         case USER_QUIT:
 64             user_quit();
 65             break;
 66         case EXIT:
 67             exit();
 68             break;
 69         default:
 70             System.out.println("输入错误，请重新输入");
 71             start();
 72             break;
 73         }
 74     }
 75 
 76     /**
 77      * Description: 
 78      */
 79     private void exit() {
 80         // TODO Auto-generated method stub
 81         if(null != this.user) {
 82             System.out.println("当前用户还没有退出，所以执行自动退出当前用户");
 83             user_quit();
 84         }else {
 85             System.out.println("你选择了退出系统");
 86             System.out.println("系统退出成功");
 87         }
 88         
 89     }
 90 
 91     /**
 92      * 退出当前用户
 93      * Description: 
 94      */
 95     private void user_quit() {
 96         // TODO Auto-generated method stub
 97         if(null != this.user) {
 98             System.out.println("你选择了退出当前用户功能");
 99             this.user = null;
100             if(null == this.user) {
101                 System.out.println("成功退出当前用户");
102             }else {
103                 System.out.println("退出当前用户失败");
104             }
105         }else {
106             System.out.println("你还没有登录成功，还不能使用该功能");
107             System.out.println("请登录！");
108             user_login();
109         }
110         start();
111     }
112 
113     /**
114      * 转账功能
115      * Description: 
116      */
117     private void user_transfer() {
118         // TODO Auto-generated method stub
119         if(null != this.user) {
120             System.out.println("你选择了转账功能！");
121             Scanner scanner = new Scanner(System.in);
122             System.out.println("请输入转入账户的用户名：");
123             String name = scanner.nextLine();
124             System.out.println("请输入转账金额：");
125             int money = Integer.parseInt(scanner.nextLine());
126             
127             Connection conn = null;
128             try {
129                 Class.forName("com.mysql.jdbc.Driver");
130                 conn = DriverManager.getConnection(
131                         "jdbc:mysql://localhost:3306/test",
132                         "root",
133                         "182838");
134                 Statement state = conn.createStatement();
135                 
136                 //转出
137                 String out_sql = "UPDATE userinfo_fury "
138                         + "SET account = account - ‘"+money+"‘ "
139                         + "WHERE username = ‘"+this.user.getUsername()+"‘ ";
140                 int judge01 = state.executeUpdate(out_sql);
141                 if(judge01 > 0) {
142                     System.out.println("转出成功");
143                 }else {
144                     System.out.println("转出失败");
145                 }
146                 
147                 //转入
148                 String in_sql = "UPDATE userinfo_fury "
149                         + "SET account = account + ‘"+money+"‘ "
150                         + "WHERE username = ‘"+name+"‘ ";
151                 int judge02 = state.executeUpdate(in_sql);
152                 if(judge02 > 0) {
153                     System.out.println("转入成功");
154                 }else {
155                     System.out.println("转入失败");
156                 }
157             }catch(Exception e) {
158                 e.printStackTrace();
159             }finally {
160                 if(null != conn) {
161                     try {
162                         conn.close();
163                     }catch(SQLException e1) {
164                         e1.printStackTrace();
165                     }
166                 }
167             }
168         }else {
169             System.out.println("请先登录！");
170             user_login();
171         }
172         start();
173     }
174 
175     /**
176      * 查询表中的所有数据
177      * Description: 
178      */
179     private void user_info() {
180         // TODO Auto-generated method stub
181         if(null != this.user) {
182             System.out.println("你选择了查询所有用户功能！");
183             Connection conn = null;
184             try {
185                 Class.forName("com.mysql.jdbc.Driver");
186                 conn = DriverManager.getConnection(
187                         "jdbc:mysql://localhost:3306/test",
188                         "root",
189                         "182838");
190                 Statement state = conn.createStatement();
191                 String sql = "SELECT id,username,password,email,nickname,account "
192                         + "FROM userinfo_fury ";
193                 ResultSet rs = state.executeQuery(sql);
194                 List<UserInfo> list = new ArrayList<UserInfo>();
195                 
196                 while(rs.next()) {
197                     int id = rs.getInt("id");
198                     String username = rs.getString("username");
199                     String password = rs.getString("password");
200                     String email = rs.getString("email");
201                     String nickname = rs.getString("nickname");
202                     double account = rs.getDouble("account");
203                     UserInfo userinfo = new UserInfo(id, username, password, email, nickname, account);
204                     list.add(userinfo);
205                 }
206                 for(UserInfo lis : list) {
207                     System.out.println(lis);
208                 }
209             }catch(Exception e) {
210                 e.printStackTrace();
211             }finally {
212                 if(null != conn) {
213                     try {
214                         conn.close();
215                     }catch(SQLException e1) {
216                         e1.printStackTrace();
217                     }
218                 }
219             }
220         }else {
221             System.out.println("请先登录");
222             user_login();
223         }
224         start();
225     }
226 
227     /**
228      * 删除用户
229      * Description: 
230      */
231     private void user_delete() {
232         // TODO Auto-generated method stub
233         if(null != this.user) {
234             System.out.println("你选择了删除用户功能");
235             System.out.println("你不是超级用户，你无法使用删除用户功能");
236         }else {
237             System.out.println("请先登录！");
238             user_login();
239         }
240         start();
241     }
242 
243     /**
244      * 修改用户信息
245      * Description: 
246      */
247     private void user_update() {
248         // TODO Auto-generated method stub
249         if(null != this.user) {
250             System.out.println("你选择了修改当前用户功能!");
251             //可改进 -->> 可由用户选择需要修改的字段
252             System.out.println("你当前的昵称为：" + this.user.getNickname());
253             Scanner scanner = new Scanner(System.in);
254             System.out.println("你想将你的昵称修改为：");
255             String nickname = scanner.nextLine();
256             
257             Connection conn = null;
258             try {
259                 Class.forName("com.mysql.jdbc.Driver");
260                 conn = DriverManager.getConnection(
261                         "jdbc:mysql://localhost:3306/test",
262                         "root",
263                         "182838");
264                 Statement state = conn.createStatement();
265                 
266                 String sql = "UPDATE userinfo_fury "
267                         + "SET nickname = ‘"+nickname+"‘ "
268                         + "WHERE username = ‘"+this.user.getUsername()+"‘ ";
269                 int judge = state.executeUpdate(sql);
270                 if(judge > 0) {
271                     this.user.setNickname(nickname);
272                     System.out.println("修改昵称成功,当前昵称为：" + this.user.getNickname());
273                 }else {
274                     System.out.println("修改昵称失败");
275                 }
276             }catch(Exception e) {
277                 e.printStackTrace();
278             }finally {
279                 if(null != conn) {
280                     try {
281                         conn.close();
282                     }catch(SQLException e1) {
283                         e1.printStackTrace();
284                     }
285                 }
286             }
287         }else {
288             System.out.println("请登录成功后在进行此操作！");
289             user_login();
290         }
291         start();
292     }
293 
294     /**
295      * 用户登录
296      * Description: 
297      */
298     private void user_login() {
299         // TODO Auto-generated method stub
300         System.out.println("你选择了用户登录功能！");
301         Scanner scanner = new Scanner(System.in);
302         System.out.println("请输入用户名:");
303         String username = scanner.nextLine();
304         System.out.println("请输入密码：");
305         String password = scanner.nextLine();
306         
307         Connection conn = null;
308         try {
309             Class.forName("com.mysql.jdbc.Driver");
310             conn = DriverManager.getConnection(
311                     "jdbc:mysql://localhost:3306/test",
312                     "root",
313                     "182838");
314             Statement state = conn.createStatement();
315             
316             String sql = "SELECT id, username, password,email, nickname,account "
317                     + "FROM userinfo_fury "
318                     + "WHERE username = ‘"+username+"‘ "
319                     + "AND password = ‘"+password+"‘ ";
320             System.out.println(sql);
321             ResultSet rs = state.executeQuery(sql);
322             if(rs.next()) {
323                 int id = rs.getInt("id");
324                 String name = rs.getString("username");
325                 String word = rs.getString("password");
326                 String email = rs.getString("email");
327                 String nickname = rs.getString("nickname");
328                 double account = rs.getDouble("account");
329                 UserInfo userinfo = new UserInfo(id, name, word, email, nickname, account);
330                 this.user = userinfo;
331                 System.out.println("登录成功,你的昵称为：" + this.user.getNickname());
332             }else {
333                 System.out.println("登录失败:" + this.user);
334             }
335             /*
336              * 注意：
337              *         当用户输入的密码个的格式是：    任意字符‘ or ‘数值开头      时无论用户名和密码正确与否，都会登录成功
338              *         因为  如果这样输入就改变了 SQL 语句的原意（在SQL语句中AND的优先级要高于OR）
339              *         实例 ： asdfaer1234‘ or ‘1
340              */
341         }catch(Exception e) {
342             e.printStackTrace();
343         }finally {
344             if(null != conn) {
345                 try {
346                     conn.close();
347                 }catch(SQLException e1) {
348                     e1.printStackTrace();
349                 }
350             }
351         }
352         start();
353     }
354 
355     /**
356      * 用户注册
357      * Description: 
358      */
359     private void user_reg() {
360         System.out.println("你选择了用户注册功能！");
361         Scanner scanner = new Scanner(System.in);
362         System.out.println("请输入用户名：");
363         String username = scanner.nextLine();
364         System.out.println("请输入密码：");
365         String password = scanner.nextLine();
366         System.out.println("请输入邮箱：");
367         String email = scanner.nextLine();
368         System.out.println("请输入昵称：");
369         String nickname = scanner.nextLine();
370         Connection conn = null;
371         try {
372             Class.forName("com.mysql.jdbc.Driver");
373             conn = DriverManager.getConnection(
374                     "jdbc:mysql://localhost:3306/test",
375                     "root",
376                     "182838");
377             Statement state = conn.createStatement();
378             String sql = "INSERT INTO userinfo_fury "
379                     + "(username,password,email,nickname) "
380                     + "VALUES "
381                     + "(‘"+username+"‘,‘"+password+"‘,‘"+email+"‘,‘"+nickname+"‘)";
382             int judge = state.executeUpdate(sql);
383             if(judge > 0) {
384                 System.out.println("注册成功");
385             }else {
386                 System.out.println("注册失败");
387             }
388         }catch(Exception e) {
389             e.printStackTrace();
390         }finally {
391             if(null != conn) {
392                 try {
393                     conn.close();
394                 }catch(SQLException e1) {
395                     e1.printStackTrace();
396                 }
397             }
398         }
399         start();
400     }
401 
402     /**
403      * 功能选择
404      * Description: 
405      */
406     private int  getCode() {
407         System.out.println("请选择功能：");
408         Scanner scanner = new Scanner(System.in);
409         int code = Integer.parseInt(scanner.nextLine());
410         return code;
411     }
412 
413     /**
414      * 界面信息
415      * Description: 
416      */
417     private void welcome() {
418         System.out.println("欢迎使用用户登录系统！");
419         System.out.println("请输入需要操作的功能序号");
420         System.out.println("======================");
421         System.out.println("================");
422         System.out.println("1 : 用户注册");
423         System.out.println("2 : 用户登录");
424         System.out.println("3 : 修改用户信息");
425         System.out.println("4 : 删除用户");
426         System.out.println("5 : 查看所有用户信息");
427         System.out.println("6 : 转账业务");
428         System.out.println("7 : 用户退出");
429         System.out.println("8 : 退出系统");
430         System.out.println("================");
431         System.out.println("======================");
432     }
433 }