通过套接字发送可序列化对象时发生NotSerializableException异常？

Question

我试图通过套接字连接发送一个自定义的对象。该类实现可串行化，但是当试图将对象写入套接字时，构造函数仍会抛出NotSerializableException。我会张贴以下相关的代码：

public class serilizableArrayHolder implements Serializable { 
    private ArrayList<Client> array= null; 

    public serilizableArrayHolder(ArrayList<Client> array) { 
     this.array=array; 
    } 

    public ArrayList<Client> getArray() { 
    return array; 
    } 
} 

这是我的定制课程。现在我试图从服务器发送一个数组列表到客户端，但我会在后面的阶段添加更多信息。发送方法贴在我的服务器类下面是张贴如下：

public void sendData(Socket clientSocket){ 
    ObjectOutputStream out; 

    try { 
     serilizableArrayHolder temp = new serilizableArrayHolder(clientCollection); 
     out = new ObjectOutputStream(clientSocket.getOutputStream()); 
     out.writeObject(temp); <---This line generates the error. 
     out.flush(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 

} 

这是我从服务器的发送方法。 clientCollection是im试图发送的arrayList。

整个客户端类：

public class Client implements Runnable, Serializable{ 
    public Thread thread = new Thread(this); 
    private Socket s; 
    private DataInputStream in; 
    private DataOutputStream out; 
    private ObjectOutputStream objOut; 
    private ServerMain server=null; 
    private String host=null; 
    private Client c; 
    private String userName; 

public Client(Socket s, String host, ServerMain server) throws IOException{ 
    c=this; 
    this.host=host; 
    this.s=s; 
    this.server=server; 
    this.userName=userName; 

    in= new DataInputStream(s.getInputStream()); 
    out=new DataOutputStream(s.getOutputStream()); 
    objOut=new ObjectOutputStream(s.getOutputStream()); 
    thread.start(); 
} 

public String getClientInfo(){ 
    return host; 
} 
public String getUserName(){ 
    return userName; 
} 
public void send(String s){ 
    try { 
     out.writeUTF(s); 
     } 
    catch (IOException e){ 
    } 
} 

public void run() { 

    while(true){ 
     try { 
      String temp = in.readUTF(); 
      if(temp.equals("sendOnline")){ 
       sendOnline(); 
      } 

      String tempHost=s.getInetAddress().getHostAddress(); 

      server.appendString(tempHost+" Skickade: "+temp+"\n"); 

      } 
      catch (IOException e) { 
       String str = s.getInetAddress().getHostName(); 
       server.clientDisconnect(str); 
       break; 
       } 
     } 

     try { 
      s.close(); 
      } 
     catch (IOException e) { 
         } 

} 
public void sendOnline(){ 
    serilizableArrayHolder temp = new serilizableArrayHolder(server.getClients()); 
    try { 
     objOut.writeObject(temp); 
     objOut.flush(); 
    } catch (IOException e) { 

     e.printStackTrace(); 
     } 
      System.out.println("Metoden anropas"); 
} 

}

新的堆栈跟踪：

java.io.NotSerializableException: java.io.DataInputStream 
Metoden anropas 
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1180) 
    at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1528) 
    at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1493) 
    at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416) 
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174) 
    at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:346) 
    at java.util.ArrayList.writeObject(ArrayList.java:710) 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
    at java.lang.reflect.Method.invoke(Method.java:601) 
    at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:962) 
    at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1480) 
    at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416) 
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174) 
    at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1528) 
    at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1493) 
    at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416) 
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174) 
    at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:346) 
    at Gesäll.Client.sendOnline(Client.java:83) 
    at Gesäll.Client.run(Client.java:58) 
    at java.lang.Thread.run(Thread.java:722) 

Answer 1

其中可达通过serilizableArrayHolder所有类都必须Serializable包括你Client类。

你Client类包含Socket，Thread，DataInputStream，DataOutputStream和ObjectOutputStream成员。他们都不是Serializable。这就是为什么你不能序列化Client类。这是另一个answer with the same topic。

我认为你应该重新考虑你的设计，并分享为什么要序列化这些对象。

Answer 2

异常告诉你这个问题。您的Client类不可序列化。要序列化一个对象，它所引用的所有对象（等等，可传递）也需要可序列化。如果您不想将其序列化，则可以标记参考transient。