feat: 新增数据库支持.

src/main/java/com/serliunx/ddns/core/factory/DatabaseInstanceFactory.java

@@ -0,0 +1,21 @@
+package com.serliunx.ddns.core.factory;
+
+import com.serliunx.ddns.core.instance.Instance;
+
+import java.util.Collections;
+import java.util.Set;
+
+/**
+ * 数据库示例工厂: 从数据库中(sqlite)存储、加载示例信息
+ *
+ * @author <a href="mailto:serliunx@yeah.net">SerLiunx</a>
+ * @version 1.0.3
+ * @since 2024/11/20
+ */
+public final class DatabaseInstanceFactory extends AbstractInstanceFactory {
+
+    @Override
+    protected Set<Instance> load() {
+        return Collections.emptySet();
+    }
+}