Update configuration system

src/main/java/Config/Config.java

@@ -0,0 +1,76 @@
+package Config;
+
+import Exceptions.InvalidConfig;
+import org.json.simple.JSONObject;
+import org.json.simple.parser.JSONParser;
+import org.json.simple.parser.ParseException;
+
+import java.io.File;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.time.LocalDate;
+import java.util.Map;
+
+public class Config {
+    static private final JSONObject template = new JSONObject(
+            Map.ofEntries(
+                    Map.entry("db",
+                            new JSONObject(Map.ofEntries(Map.entry("host", ""),
+                                    Map.entry("database", ""),
+                                    Map.entry("user", ""),
+                                    Map.entry("password", "")))
+                    ),
+                    Map.entry("startDate", ""),
+                    Map.entry("endDate", "")
+            )
+    );
+
+    static private void createConfig() {
+        File f = new File("./config.json");
+        try {
+            FileWriter fw = new FileWriter(f);
+            fw.write(template.toJSONString());
+            fw.close();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    static private boolean checkConfig(JSONObject jsonObject, JSONObject template) {
+        for (Object k : template.keySet().toArray())
+            if (!jsonObject.containsKey(k) ||
+                    (template.get(k).getClass() == JSONObject.class &&
+                            !checkConfig((JSONObject) jsonObject.get(k), (JSONObject) template.get(k))))
+                return false;
+        return true;
+    }
+
+    static private JSONObject getConfig() throws InvalidConfig {
+        try {
+            File f = new File("./config.json");
+            if (!f.exists())
+                createConfig();
+            JSONObject config = (JSONObject) new JSONParser().parse(new FileReader(f));
+            if (checkConfig(config, template))
+                return config;
+            else
+                throw new InvalidConfig();
+        } catch (ParseException | IOException e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+    static public JSONObject getDBAuth() throws InvalidConfig {
+        return (JSONObject) Config.getConfig().get("db");
+    }
+
+    static public LocalDate getStartDate() throws InvalidConfig {
+        return (LocalDate) Config.getConfig().get("startDate");
+    }
+
+    static public LocalDate getEndDate() throws InvalidConfig {
+        return (LocalDate) Config.getConfig().get("endDate");
+    }
+}

src/main/java/DB/DB.java

@@ -1,13 +1,12 @@
 package DB;
 
+import Config.Config;
 import Exceptions.AlreadyOnTable;
+import Exceptions.InvalidConfig;
 import Exceptions.NotFoundInTable;
 import lombok.Getter;
 import org.json.simple.JSONObject;
-import org.json.simple.parser.JSONParser;
-import org.json.simple.parser.ParseException;
 
-import java.io.*;
 import java.lang.reflect.InvocationTargetException;
 import java.sql.*;
 import java.sql.Date;
@@ -16,39 +15,15 @@ import java.util.*;
 public class DB {
     @Getter static private Connection connection;
 
-    static private JSONObject getAuth() {
-        try {
-            File f = new File("./config.json");
-            if (!f.exists()) {
-                FileWriter fw = new FileWriter(f);
-                fw.write(
-                        new JSONObject(
-                                Map.ofEntries(
-                                        Map.entry("host", ""),
-                                        Map.entry("database", ""),
-                                        Map.entry("user", ""),
-                                        Map.entry("password", "")
-                                )
-                        ).toJSONString()
-                );
-                fw.close();
-            }
-            return (JSONObject) new JSONParser().parse(new FileReader(f));
-        } catch (ParseException | IOException e) {
-            e.printStackTrace();
-            return null;
-        }
-    }
-
     static public boolean connect() {
         try {
             if (connection == null || connection.isClosed()) {
-                JSONObject auth = getAuth();
+                JSONObject auth = Config.getDBAuth();
                 if (auth != null)
                     connection = DriverManager.getConnection("jdbc:mariadb://"+auth.get("host")+"/"+auth.get("database")+"?user="+auth.get("user")+"&password="+auth.get("password"));
                 return true;
             }
-        } catch (SQLException e) {
+        } catch (SQLException | InvalidConfig e) {
             return false;
         }
         return false;

src/main/java/Exceptions/InvalidConfig.java

@@ -0,0 +1,7 @@
+package Exceptions;
+
+public class InvalidConfig extends Exception {
+    public InvalidConfig() {
+        super("Configuration file is invalid");
+    }
+}