进行RPC调用时发生序列化异常 [英] Serialization Exception while making an RPC call

问题描述

我创建了一个非常基本的应用程序。我只有一个服务类和一个相应的Async类，它只包含Java类型并且没有自定义类。但是我仍然得到了序列化异常。

我的服务类看起来像这样。

  public interface MyService extends RemoteService {
 public String getName（）; 
 public Object getAdditionalDetials（ArrayList< String> ids）; 
 public Date getJoiningDate（）; 
} 
  

我的异步界面看起来像这样

  public interface MyServiceAsync {
 public void getName（AsyncCallback< String> callback）; 
 public void getAdditionalDetials（ArrayList< String> ids，AsyncCallback< Object> callback）; 
 public void getJoiningDate（AsyncCallback< Date> callback）; 
} 
  

我知道我犯了一些愚蠢的错误。 b

解决方案

我很熟悉gwt rpc和序列化机制，但会尝试回答您的问题。 >每当你编写涉及RPC的类时，GWT都会创建一个序列化策略文件。序列化策略文件包含可被序列化的允许类型的白名单。

在您的服务方法中，您提及并引用的所有类型将自动添加到此列表中if他们实现了 IsSerializable 。在你的情况下，你使用了以下两种方法：
public Date getJoiningDate（）;

这里使用了 String 和 Date 作为返回类型，因此将它添加到序列化策略文件中。但在下面的方法中，它们存在一个问题，

  public Object getAdditionalDetials（Arraylist< String> ids）; 
  

这里您使用了 ArrayList和String 是不是问题，他们将被添加到您的白名单，但问题是你提到返回类型为 Object 。这里GWT编译器不知道要添加到白名单或序列化策略的类型，因此它不会传递你的RPC调用。解决方案是使用提及的类实现 IsSerializable ，而不是提及类型 Object 的返回类型。

I have created a very basic application. I have only one service class and a corresponding Async class which contains only Java types and no custom classes. But still I get the serialization exception.

My service class looks like this.

public interface MyService extends RemoteService {
  public String getName();
  public Object getAdditionalDetials(ArrayList<String> ids);
  public Date getJoiningDate();
}

My async interface looks like this

public interface MyServiceAsync {
  public void getName(AsyncCallback<String> callback);
  public void getAdditionalDetials(ArrayList<String> ids, AsyncCallback<Object> callback);
  public void getJoiningDate(AsyncCallback<Date> callback);
}

I know I am making some stupid mistake.

解决方案

I am Naive in gwt rpc and serialization mechanism, but will try to answer your question.

Whenever you write classes involving an RPC, GWT creates a Serialization Policy File. The serialization policy file contains a whitelist of allowed types which may be serialized.

In your Service methods, all the types you mention and refer will be automatically added to this list if they implements IsSerializable. In your case you have used the following two methods,

public String getName();
public Date getJoiningDate();

Here you have used String and Date as your return types and hence it is added to your Serialization Policy File. But in the below method their lies a problem,

public Object getAdditionalDetials(Arraylist<String> ids);

Here you have used ArrayList and String that is not a problem and they will be added to your whitelist, but the problem is you have mentioned return type as Object. Here GWT Compiler does not know what type to be added to whitelist or Serialization Policy and hence it wont pass your RPC call. The solution is use mention a class which implements IsSerializable instead of mentioning the return type of type Object.

这篇关于进行RPC调用时发生序列化异常的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！