Add package assignment1

assignment1/PasswordChange.java

@@ -0,0 +1,91 @@
+package assignment1;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.util.Scanner;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class PasswordChange {
+    static final String DBURL = "jdbc:mysql://localhost:3306/xiaoshou?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=GMT";
+
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+        Connection conn = null;
+        PreparedStatement pstmt = null;
+        ResultSet rs = null;
+        try {
+            Class.forName("com.mysql.cj.jdbc.Driver");
+            conn = DriverManager.getConnection(DBURL);
+            System.out.print("请输入用户名：");
+            String username = scanner.nextLine();
+            String checkUserSql = "SELECT xingming FROM t_yong WHERE yonghuming=?";
+            pstmt = conn.prepareStatement(checkUserSql);
+            pstmt.setString(1, username);
+            rs = pstmt.executeQuery();
+            if (!rs.next()) {
+                System.out.println("该用户不存在，请重新输入");
+                return;
+            }
+            System.out.print("请输入当前用户的原密码：");
+            String oldPassword = scanner.nextLine();
+            String checkPasswordSql = "SELECT xingming FROM t_yong WHERE yonghuming=? AND mima=MD5(?)";
+            pstmt = conn.prepareStatement(checkPasswordSql);
+            pstmt.setString(1, username);
+            pstmt.setString(2, oldPassword);
+            rs = pstmt.executeQuery();
+            if (!rs.next()) {
+                System.out.println("原密码输入不正确，请重新输入");
+                return;
+            }
+            String newPassword;
+            while (true) {
+                System.out.print("请设置新的密码：");
+                newPassword = scanner.nextLine();
+                if (!isPasswordComplex(newPassword))
+                    System.out.println("您的密码不符合复杂性要求（密码长度不少于6个字符，至少有一个小写字母，至少有一个大写字母，至少一个数字），请重新输入：");
+                else
+                    break;
+            }
+            System.out.print("请输入确认密码：");
+            String confirmPassword = scanner.nextLine();
+            if (!newPassword.equals(confirmPassword)) {
+                System.out.println("两次输入的密码必须一致，请重新输入确认密码：");
+                return;
+            }
+            String updatePasswordSql = "UPDATE t_yong SET mima=? WHERE yonghuming=?";
+            pstmt = conn.prepareStatement(updatePasswordSql);
+            pstmt.setString(1, Encrypt.MD5(newPassword));
+            pstmt.setString(2, username);
+            int result = pstmt.executeUpdate();
+            if (result > 0)
+                System.out.println("您已成功修改密码，请谨记");
+            else
+                System.out.println("密码修改失败，请重试");
+        } catch (Exception e) {
+            e.printStackTrace();
+        } finally {
+            try {
+                if (rs != null)
+                    rs.close();
+                if (pstmt != null)
+                    pstmt.close();
+                if (conn != null)
+                    conn.close();
+            } catch (SQLException se) {
+                se.printStackTrace();
+            }
+        }
+    }
+
+    public static boolean isPasswordComplex(String password) {
+        if (password.length() < 6)
+            return false;
+        Pattern pattern = Pattern.compile("^(?=.*[0-9])(?=.*[a-z])(?=.*[A-Z]).{6,}$");
+        Matcher matcher = pattern.matcher(password);
+        return matcher.matches();
+    }
+}