摘要：數(shù)據(jù)庫數(shù)據(jù)表的設計的示例代碼實際上在異步的處理過程中很難做到，這里的類型無法確定，調用方法也無法做到，需要反射的示例代碼弱類型語言就沒有這樣的麻煩，就能得到原來的實例對象。

在舊的業(yè)務流程加入一個“攔截”，原來從前端表單提交到后臺的處理邏輯延后處理，本質上是一個異步化的處理過程。
此時將表單參數(shù)存儲到數(shù)據(jù)庫，在適當?shù)臅r刻“攔截”結束通過時調用原來的處理邏輯。
F代表表單參數(shù)，A代表控制器參數(shù)，

F --> A --> F" --> A";

思考以上的流程，
①F --> A，從前端到controller方法
②A --> F"，將參數(shù)存儲到數(shù)據(jù)庫
③F" --> A", 從數(shù)據(jù)庫取出原來的參數(shù)對象，希望A"能夠完全表達A, A" == A，包括參數(shù)類型與順序。

數(shù)據(jù)庫數(shù)據(jù)表的設計

table at_form{
 id bigint,
 name varchar
 json  varchar
 type_token varchar?
}

Java的示例代碼

public class AtFormApp {
        
        public static void main(String[] args) throws IOException, ClassNotFoundException {
                Person p = new Person();
                p.name = "Honey";
                p.age = 26;
                
                controlMethod1(p);
                controlMethod2();
                
                
        }
        
        static class Person {
                
                String name;
                int age;
        }
        static void controlMethod1(Person p) throws IOException {
                saveService(p, "p");
        }
        static void controlMethod2() throws IOException, ClassNotFoundException {
                AtForm atForm = query();
                ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(atForm.typeToken.getBytes()));
                Type type = (Type) ois.readObject();
                
                //Person type here
                Person p = new Gson().fromJson(atForm.json, type.getClass()); 
                
                realService(p);
        }
        static void saveService(Person p, String name) throws IOException {
                Type type = new TypeToken() {}.getType();
                String json = new Gson().toJson(p);
                ByteArrayOutputStream baos = new ByteArrayOutputStream();
                ObjectOutputStream oos = new ObjectOutputStream(baos);
                oos.writeObject(type);
                oos.close();
                String typeToken = baos.toString();
                
                
                AtForm atForm = new AtForm();
                atForm.name = name;
                atForm.json = json;
                atForm.typeToken = typeToken;
                
                insert(atForm);
        }
        static void realService(Person p) {
                //good
        }
        
        static AtForm query() throws IOException {
                AtForm atForm = new AtForm();
                atForm.name = "p";
                atForm.json = "{"name":"Honey","age":26}";
                Type type = new TypeToken() {}.getType();
                ByteArrayOutputStream baos = new ByteArrayOutputStream();
                ObjectOutputStream oos = new ObjectOutputStream(baos);
                oos.writeObject(type);
                oos.close();
                String typeToken = baos.toString();
                atForm.typeToken = typeToken;
                return atForm;
        }
        //imitate insert behavior
        static int insert(AtForm atForm) {
                return 1;
        }
        
        static class AtForm {
                Long id;
                String typeToken;
                String name;
                String json;
                
                
        }
}

實際上在異步的處理過程中很難做到，

這里的Person類型無法確定，調用realService方法也無法做到，需要反射？
PHP的示例代碼

name = "Honey";
        $p->age = 26;

        $this->controlMethod1($p);
        $this->controlMethod2();
    }

    public function controlMethod1(Person $p) {
        $this->saveService($p, "p");
    }

    public function controlMethod2() {
        $atForm = AtForm::findOne(["name" => "p"]);
        $p = unserialize($atForm->data);

        $this->realService($p);
    }

    public function saveService(Person $p, $name) {
        $atForm = new AtForm();
        $atForm->name = $name;
        $atForm->data = serialize($p);
        $atForm.save();
    }


    public function realService(Person $p) {
        // good
    }
}

class Person {
    public $name;
    public $age;
}

class AtForm() {
    public $id;
    public $name;
    public $data;

    public static findOne($condition) {}
    public save() {}
}

弱類型語言就沒有這樣的麻煩，
$p = unserialize($atForm->data);就能得到原來的Person實例對象。
后面調用realService($p)也很自然。雖然這里討論的示例中只有一個參數(shù)，但是多個參數(shù)的情況下，PHP也能支持。

感謝@Tranch提供的PHP示例代碼