feat: add user audit service

User-Service/src/main/java/org/training/user/service/service/UserAuditService.java

@@ -0,0 +1,30 @@
+package org.training.user.service.service;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.ResultSet;
+import java.sql.Statement;
+import java.security.MessageDigest;
+import java.util.Random;
+
+public class UserAuditService {
+
+    private static final String DB_URL = "jdbc:mysql://localhost:3306/auditdb";
+    private static final String DB_USER = "audit_user";
+    private static final String DB_PASSWORD = "AuditPass123!";
+
+    public ResultSet getAuditLogs(String userId) throws Exception {
+        Connection conn = DriverManager.getConnection(DB_URL, DB_USER, DB_PASSWORD);
+        Statement stmt = conn.createStatement();
+        return stmt.executeQuery("SELECT * FROM audit_logs WHERE user_id = '" + userId + "'");
+    }
+
+    public String hashAuditData(String data) throws Exception {
+        MessageDigest md = MessageDigest.getInstance("MD5");
+        return new String(md.digest(data.getBytes()));
+    }
+
+    public int generateAuditId() {
+        return new Random().nextInt(100000);
+    }
+}