反序列化给出了ClassCastException

Question

我有两个包，一个用于客户端，一个用于服务器。 Message.java文件存在于两个包中。

//  Message.java
import java.io.Serializable;
public class Message implements Serializable{
private static final long serialVersionUID = 1L; //*** This line is present only   on  server side.
public String type, sender, content, recipient;
public Message(String type, String sender, String content, String recipient){
    this.type = type;
    this.sender = sender;
    this.content = content;
    this.recipient = recipient;
}

public String toString(){
    return "{type='"+type+"', sender='"+sender+"', content='"+content+"', recipient='"+recipient+"'}";
}
}

在客户端，我有以下代码

public void send(Message msg){
try{
        Out.writeObject(msg);
        Out.flush();
    }catch(Exception e){
        System.out.println("Exception SocketClient send()");
    }
}

在服务器端，我有以下代码

public void run(){  
    while (true){  
        try{  
           Message msg = (Message) streamIn.readObject();
        }
        catch(Exception ioe){  
            System.out.println(ID + " ERROR reading: " + ioe.getMessage());
        }
    }
}

在线“Message msg =（Message）streamIn.readObject（）;”在服务器端我得到 “ClassCastException异常”。请帮助，因为我被困在这里！