diff --git a/Database/Connection.php b/Database/Connection.php
index 3effed50..a578ab76 100644
--- a/Database/Connection.php
+++ b/Database/Connection.php
@@ -5,6 +5,8 @@
  * Date: 2018/3/30 0030
  * Time: 14:09
  */
+declare(strict_types=1);
+
 
 namespace Database;
 
@@ -27,23 +29,23 @@ class Connection extends Component
 	const TRANSACTION_COMMIT = 'transaction::commit';
 	const TRANSACTION_ROLLBACK = 'transaction::rollback';
 
-	public $id = 'db';
-	public $cds = '';
-	public $password = '';
-	public $username = '';
-	public $charset = 'utf-8';
-	public $tablePrefix = '';
+	public string $id = 'db';
+	public string $cds = '';
+	public string $password = '';
+	public string $username = '';
+	public string $charset = 'utf-8';
+	public string $tablePrefix = '';
 
-	public $timeout = 1900;
+	public int $timeout = 1900;
 
-	public $maxNumber = 200;
+	public int $maxNumber = 200;
 
 	/**
 	 * @var bool
 	 * enable database cache
 	 */
-	public $enableCache = false;
-	public $cacheDriver = 'redis';
+	public bool $enableCache = false;
+	public string $cacheDriver = 'redis';
 
 	/**
 	 * @var array
@@ -54,10 +56,9 @@ class Connection extends Component
 	 *    'password' => 'root'
 	 * ]
 	 */
-	public $slaveConfig = [];
+	public array $slaveConfig = [];
 
-	/** @var Schema $_schema */
-	private $_schema = null;
+	private ?Schema $_schema = null;
 
 
 	/**
diff --git a/System/Core/JSON.php b/System/Core/JSON.php
index 0411186e..1fb731d6 100644
--- a/System/Core/JSON.php
+++ b/System/Core/JSON.php
@@ -6,8 +6,12 @@
  * Time: 01:04
  */
 
+declare(strict_types=1);
+
 namespace Snowflake\Core;
 
+use Exception;
+
 /**
  * Class JSON
  * @package Snowflake\Snowflake\Core
@@ -16,41 +20,22 @@ class JSON
 {
 
 	/**
-	 * @param $data
+	 * @param string|array|mixed $data
 	 * @return false|string
-	 * @throws \Exception
+	 * @throws Exception
 	 */
-	public static function encode($data)
+	public static function encode(string|array|object $data)
 	{
 		if (empty($data)) {
 			return $data;
 		}
 		if (is_array($data)) {
-			return self::filter(ArrayAccess::toArray($data));
+			return json_encode(ArrayAccess::toArray($data));
 		}
 		return $data;
 	}
 
 
-	/**
-	 * @param $data
-	 * @return mixed
-	 */
-	private static function filter($data)
-	{
-		array_walk_recursive($data, function ($value, $key) use ($data) {
-			if (!is_numeric($value)) {
-				return;
-			}
-			if (is_int(+$value)) {
-				$value = +$value;
-			}
-			$data[$key] = $value;
-		});
-		return json_encode($data, JSON_UNESCAPED_UNICODE);
-	}
-
-
 	/**
 	 * @param $data
 	 * @param bool $asArray
@@ -107,7 +92,7 @@ class JSON
 	 * @param $state
 	 * @param $body
 	 * @return false|int|string
-	 * @throws \Exception
+	 * @throws Exception
 	 */
 	public static function output($state, $body)
 	{