diff --git a/.gitignore b/.gitignore
index 0d330a8..c4daf32 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 vendor/
-composer.lock
\ No newline at end of file
+composer.lock
+.idea/
diff --git a/composer.json b/composer.json
index a62cfe6..2837828 100644
--- a/composer.json
+++ b/composer.json
@@ -18,20 +18,20 @@
     "require": {
         "php": ">=5.4.0",
         "ext-posix": "*",
-        "jenner/simple_fork": "1.1.2",
-        "monolog/monolog": "1.17.1",
-        "react/http": "v0.4.1",
-        "symfony/process": "v2.7.5"
+        "jenner/simple_fork": "1.1.*",
+        "monolog/monolog": "1.17.*",
+        "react/http": "v0.4.*",
+        "symfony/process": "v2.7.*"
     },
     "require-dev": {
-        "guzzle/guzzle": "v3.9.3",
+        "guzzle/guzzle": "v3.9.*",
         "ext-redis": "*"
     },
     "suggest": {
-        "ext-libevent": ">=0.1.0",
+        "ext-libevent": "0.1.*",
         "ext-event": "~1.0",
         "ext-libev": "*",
-        "guzzle/guzzle": "v3.9.3",
+        "guzzle/guzzle": "v3.9.*",
         "ext-redis": "*"
     },
     "autoload": {
diff --git a/src/Jenner/Crontab/Daemon.php b/src/Jenner/Crontab/Daemon.php
index e62a9dd..916d0a6 100644
--- a/src/Jenner/Crontab/Daemon.php
+++ b/src/Jenner/Crontab/Daemon.php
@@ -62,18 +62,6 @@ public function start()
         $crontab = $this->createCrontab();
         $loop = Factory::create();
 
-        // add task loader timer is exists.
-        if (!empty($this->task_loader) && is_callable($this->task_loader)) {
-            $loop->addPeriodicTimer(60, function () {
-                $start_time = time();
-                $this->task_loader = call_user_func($this->task_loader);
-                $execution_time = time() - $start_time;
-                if ($execution_time > 60) {
-                    $this->logger->warning("task loader's execution time is more than 60 seconds.");
-                }
-            });
-        }
-
         // add periodic timer
         $loop->addPeriodicTimer(60, function () use ($crontab, $loop) {
             $loop->addTimer(60 - time() % 60, function () use ($crontab) {
@@ -100,14 +88,6 @@ public function start()
         $loop->run();
     }
 
-    public function registerTaskLoader($loader)
-    {
-        if (!is_callable($loader)) {
-            throw new \InvalidArgumentException("task loader is not callable");
-        }
-        $this->task_loader = $loader;
-    }
-
     /**
      * create crontab object
      *
@@ -118,14 +98,14 @@ protected function createCrontab()
         $tasks = $this->formatTasks();
         $missions = array();
         foreach ($tasks as $task) {
-            if($task['out'] instanceof LoggerInterface) {
+            if ($task['out'] instanceof LoggerInterface) {
                 $out = $task['out'];
-            }else{
+            } else {
                 $out = MissionLoggerFactory::create($task['out']);
             }
-            if($task['err'] instanceof LoggerInterface) {
+            if ($task['err'] instanceof LoggerInterface) {
                 $err = $task['err'];
-            }else{
+            } else {
                 $err = MissionLoggerFactory::create($task['err']);
             }
 
@@ -164,18 +144,27 @@ protected function formatTasks()
     /**
      * @param $tasks
      */
-    public function setTasks($tasks)
+    public function addTasks($tasks)
     {
         $must = array('name', 'cmd', 'time');
         foreach ($tasks as $task) {
-            foreach ($must as $key) {
-                if (!array_key_exists($key, $task)) {
-                    $message = "task must have a {$key} value";
-                    throw new \InvalidArgumentException($message);
-                }
-            }
+            $this->addTask($task);
+        }
+    }
 
-            $this->tasks[$task['name']] = $task;
+    /**
+     * @param $task
+     */
+    public function addTask($task)
+    {
+        $must = array('name', 'cmd', 'time');
+        foreach ($must as $key) {
+            if (!array_key_exists($key, $task)) {
+                $message = "task must have a {$key} value";
+                throw new \InvalidArgumentException($message);
+            }
         }
+
+        $this->tasks[$task['name']] = $task;
     }
 }
\ No newline at end of file
diff --git a/src/Jenner/Crontab/Mission.php b/src/Jenner/Crontab/Mission.php
index be208e8..293d38a 100644
--- a/src/Jenner/Crontab/Mission.php
+++ b/src/Jenner/Crontab/Mission.php
@@ -95,109 +95,129 @@ public function __construct(
     }
 
     /**
-     * get or set name
-     *
-     * @param null $name
      * @return string
      */
-    public function name($name = null)
+    public function getName()
     {
-        if (!is_null($name)) {
-            $this->name = $name;
-        } else {
-            return $this->name;
-        }
+        return $this->name;
+    }
+
+    /**
+     * @param string $name
+     */
+    public function setName($name)
+    {
+        $this->name = $name;
     }
 
     /**
-     * get or set cmd
-     *
-     * @param null $cmd
      * @return string
      */
-    public function cmd($cmd = null)
+    public function getCmd()
     {
-        if (!is_null($cmd)) {
-            $this->cmd = $cmd;
-        } else {
-            return $this->cmd;
-        }
+        return $this->cmd;
     }
 
+    /**
+     * @param string $cmd
+     */
+    public function setCmd($cmd)
+    {
+        $this->cmd = $cmd;
+    }
 
     /**
-     * get or set time
-     *
-     * @param null $time
-     * @return null
+     * @return LoggerInterface
      */
-    public function time($time = null)
+    public function getOut()
     {
-        if (!is_null($time)) {
-            $this->time = $time;
-        } else {
-            return $this->time;
-        }
+        return $this->out;
     }
 
     /**
-     * get or set out
-     *
      * @param LoggerInterface $out
-     * @return null|string
      */
-    public function out(LoggerInterface $out = null)
+    public function setOut(LoggerInterface $out)
     {
-        if (!is_null($out)) {
-            $this->out = $out;
-        } else {
-            return $this->out;
-        }
+        $this->out = $out;
+    }
+
+    /**
+     * @return LoggerInterface
+     */
+    public function getErr()
+    {
+        return $this->err;
     }
 
     /**
-     * get or set err
-     *
      * @param LoggerInterface $err
-     * @return null|string
      */
-    public function err(LoggerInterface $err = null)
+    public function setErr(LoggerInterface $err)
     {
-        if (!is_null($err)) {
-            $this->err = $err;
-        } else {
-            return $this->err;
-        }
+        $this->err = $err;
     }
 
     /**
-     * get or set user
-     *
-     * @param null $user
-     * @return null|string
+     * @return string
      */
-    public function user($user = null)
+    public function getUser()
     {
-        if (!is_null($user)) {
-            $this->user = $user;
-        } else {
-            return $this->user;
-        }
+        return $this->user;
+    }
+
+    /**
+     * @param string $user
+     */
+    public function setUser($user)
+    {
+        $this->user = $user;
+    }
+
+    /**
+     * @return string
+     */
+    public function getGroup()
+    {
+        return $this->group;
+    }
+
+    /**
+     * @param string $group
+     */
+    public function setGroup($group)
+    {
+        $this->group = $group;
     }
 
+    /**
+     * @return string
+     */
+    public function getComment()
+    {
+        return $this->comment;
+    }
 
     /**
-     * get or set group
+     * @param string $comment
+     */
+    public function setComment($comment)
+    {
+        $this->comment = $comment;
+    }
+
+    /**
+     * get or set err
      *
-     * @param null $group
+     * @param LoggerInterface $err
      * @return null|string
      */
-    public function group($group = null)
+    public function err(LoggerInterface $err = null)
     {
-        if (!is_null($group)) {
-            $this->group = $group;
+        if (!is_null($err)) {
+            $this->err = $err;
         } else {
-            return $this->group;
+            return $this->err;
         }
     }
 
@@ -209,12 +229,28 @@ public function group($group = null)
      */
     public function needRun($time)
     {
-        if ($time - CrontabParse::parse($this->time(), $time) == 0) {
+        if ($time - CrontabParse::parse($this->getTime(), $time) == 0) {
             return true;
         }
         return false;
     }
 
+    /**
+     * @return string
+     */
+    public function getTime()
+    {
+        return $this->time;
+    }
+
+    /**
+     * @param string $time
+     */
+    public function setTime($time)
+    {
+        $this->time = $time;
+    }
+
     /**
      * @return array
      */
@@ -258,7 +294,7 @@ protected function setUserAndGroup()
     {
         if (!is_null($this->user)) {
             if (!is_null($this->group)) {
-                $group_info = posix_getgrnam($this->user);
+                $group_info = posix_getgrnam($this->group);
                 $group_id = $group_info['gid'];
                 if (!posix_setgid($group_id)) {
                     throw new \RuntimeException("set group failed");