added nullable check

src/Utils/Business/LuMethodDocParser.php

                     }
                     else if (!is_null($currentParam)) {
                         $methodName = $command;
-                        $constraint = new LuParameterConstraintDbo();
-                        $constraint->setMethod($methodName);
-                        $args = [];
-                        $argMatches = [];
-                        if (preg_match_all('/ *(-?(?:\d*\.\d+|\d+|true|false|null|"[^"]*"|\'[^\']*\'))/', $line, $argMatches) !== false) {
-                            $args = $argMatches[1];
-                            foreach ($args as $key => $arg) {
-                                $argLower = strtolower($arg);
-                                if ($arg[0] == '"' || $arg[0] == "'") {
-                                    $args[$key] = substr($arg, 1, count($arg) - 2);
-                                }
-                                else if ($argLower == "true") {
-                                    $args[$key] = true;
-                                }
-                                else if ($argLower == "false") {
-                                    $args[$key] = false;
-                                }
-                                else if ($argLower == "null") {
-                                    $args[$key] = null;
-                                }
-                                else if (strpos($arg, ".") !== false) {
-                                    $args[$key] = floatval($arg);
-                                }
-                                else {
-                                    $args[$key] = intval($arg);
+                        if ($methodName == "nullable") {
+                            $currentParam->setNotNull(false);
+                        }
+                        else {
+                            $constraint = new LuParameterConstraintDbo();
+                            $constraint->setMethod($methodName);
+                            $args = [];
+                            $argMatches = [];
+                            if (preg_match_all('/ *(-?(?:\d*\.\d+|\d+|true|false|null|"[^"]*"|\'[^\']*\'))/', $line, $argMatches) !== false) {
+                                $args = $argMatches[1];
+                                foreach ($args as $key => $arg) {
+                                    $argLower = strtolower($arg);
+                                    if ($arg[0] == '"' || $arg[0] == "'") {
+                                        $args[$key] = substr($arg, 1, count($arg) - 2);
+                                    } else if ($argLower == "true") {
+                                        $args[$key] = true;
+                                    } else if ($argLower == "false") {
+                                        $args[$key] = false;
+                                    } else if ($argLower == "null") {
+                                        $args[$key] = null;
+                                    } else if (strpos($arg, ".") !== false) {
+                                        $args[$key] = floatval($arg);
+                                    } else {
+                                        $args[$key] = intval($arg);
+                                    }
                                 }
                             }
+                            $constraint->setArguments($args);
+                            $currentParam->addConstraint($constraint);
                         }
-                        $constraint->setArguments($args);
-                        $currentParam->addConstraint($constraint);
                     }
                 }
                 else {

src/Utils/Controller/LuRoute.php

                 else {
                     if (array_key_exists($param->getName(), $parameters)) {
                         $args[$param->getName()] = $this->getParam($param, $parameters[$param->getName()]);
+                        
+                        if (is_null($args[$param->getName()]) && 
+                            array_key_exists($param->getName(), $doc->getParams()) &&
+                            $doc->getParams()[$param->getName()]->isNotNull()) {
+                            throw new LuBusinessException("Parameter '" . $param->getName() . "' can not be null", 400);
+                        }
                     }
                     else {
                         throw new LuBusinessException("Missing parameter '" . $param->getName() . "'", 400);

src/Utils/Dbo/LuDbo.php

      */
     public static function jsonDeserialize($json)
     {
+        if (is_null($json)) {
+            return null;
+        }
         $dbo = new static();
         $reflect = new \ReflectionClass(static::class);
         $properties = $reflect->getProperties();

src/Utils/Dbo/LuParameterDbo.php

 
 class LuParameterDbo extends LuDbo
 {
+    /**
+     * @var bool $_notNull
+     */
+    private $_notNull = true;
+
+    /**
+     * @return boolean
+     */
+    public function isNotNull()
+    {
+        return $this->_notNull;
+    }
+
+    /**
+     * @param boolean $notNull
+     */
+    public function setNotNull($notNull)
+    {
+        $this->_notNull = $notNull;
+    }
+    
     /**
      * @var $_summary string
      */
      * @var $_constraints LuParameterConstraintDbo[]
      */
     private $_constraints = [];
-    
-    function jsonSerialize()
-    {
-        $constraints = [];
-        foreach ($this->_constraints as $constraint) {
-            $constraints[] = $constraint->jsonSerialize();
-        }
-        return [
-            "Name" => $this->_name,
-            "Type" => $this->_type,
-            "Summary" => $this->_summary,
-            "Constraints" => $constraints
-        ];
-    }
 }

tests/LuMethodDocParserTest.php

         }
         
         $expectedParams = [
-            ["Name" => 'myvar', "Type" => "MyType", "Summary" => "some doc\n",
+            ["NotNull" => true, "Summary" => "some doc\n", "Type" => "MyType", "Name" => 'myvar',
                 "Constraints" => []],
-            ["Name" => 'myvar2', "Type" => "MyType", "Summary" => "some other doc\n",
+            ["NotNull" => true, "Summary" => "some other doc\n", "Type" => "MyType", "Name" => 'myvar2',
                 "Constraints" => []]
         ];
         
         }
 
         $expectedParams = [
-            'myvar' => ["Name" => 'myvar', "Type" => "MyType", "Summary" => "some doc\n",
+            'myvar' => ["NotNull" => true, "Summary" => "some doc\n", "Type" => "MyType", "Name" => 'myvar',
                 "Constraints" => []],
-            'myvar2' => ["Name" => 'myvar2', "Type" => "MyType", "Summary" => "some other doc\non another line\n",
-                "Constraints" => []]
+            'myvar2' => ["NotNull" => true, "Summary" => "some other doc\non another line\n", "Type" => "MyType",
+                "Name" => 'myvar2', "Constraints" => []]
         ];
 
         $this->assertSame($expectedParams, $params);
      * Too much doc
      * @param MyType $myvar2 some other doc
      * on another line
+     * @nullable
      * @min 42
      * @max 42
      * @between 0 42
         }
 
         $expectedParams = [
-            'myvar' => ["Name" => 'myvar', "Type" => "MyType", "Summary" => "some doc\nToo much doc\n",
-                "Constraints" => []],
-            'myvar2' => ["Name" => 'myvar2', "Type" => "MyType", "Summary" => "some other doc\non another line\nand another\n",
+            'myvar' => ["NotNull" => true, "Summary" => "some doc\nToo much doc\n", "Type" => "MyType",
+                "Name" => 'myvar', "Constraints" => []],
+            'myvar2' => ["NotNull" => false, "Summary" => "some other doc\non another line\nand another\n",
+                "Type" => "MyType", "Name" => 'myvar2',
                 "Constraints" => [
                     ["Method" => "min", "Arguments" => [42]],
                     ["Method" => "max", "Arguments" => [42]],