feat(database): 优化SQLite数据库连接获取方式

src/main/java/cc/baka9/catseedlogin/bukkit/database/SQLite.java

@@ -1,38 +1,30 @@
 package cc.baka9.catseedlogin.bukkit.database;
 
-import org.bukkit.plugin.java.JavaPlugin;
-
 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.SQLException;
 
+import org.bukkit.plugin.java.JavaPlugin;
+
 public class SQLite extends SQL {
     private Connection connection;
 
     public SQLite(JavaPlugin javaPlugin){
         super(javaPlugin);
     }
 
-
     @Override
-public Connection getConnection() {
-    try {
-        if (this.connection != null && !this.connection.isClosed()) {
-            return this.connection;
-        }
-
-        if (!plugin.getDataFolder().exists()) {
-            plugin.getDataFolder().mkdir();
+    public Connection getConnection() {
+        try {
+            if (connection == null || connection.isClosed()) {
+                if (!plugin.getDataFolder().exists()) plugin.getDataFolder().mkdir();
+                Class.forName("org.sqlite.JDBC");
+                connection = DriverManager.getConnection("jdbc:sqlite:" + plugin.getDataFolder().getAbsolutePath() + "/accounts.db");
+            }
+            return connection;
+        } catch (ClassNotFoundException | SQLException e) {
+            e.printStackTrace();
+            return null;
         }
-
-        Class.forName("org.sqlite.JDBC");
-        this.connection = DriverManager.getConnection("jdbc:sqlite:" + plugin.getDataFolder().getAbsolutePath() + "/accounts.db");
-
-        return this.connection;
-    } catch (ClassNotFoundException | SQLException e) {
-        e.printStackTrace();
-        return null;
     }
 }
-
-}