java - 通过套接字发送可序列化对象时出现 NotSerializableException？

Question

我正在尝试通过套接字连接发送定制对象。该类实现了可序列化，但当我尝试将对象写入套接字时，构造函数仍然抛出 NotSerializableException。我将在下面发布相关代码:

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

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

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

这是我定制的类(class)。现在我正在尝试从服务器向客户端发送一个数组列表，但我会在稍后阶段添加其他信息。发送方法在我的服务器类中发布如下:

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();
    }

}

这是我从服务器发送的方法。 clientCollection 是我尝试发送的 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

异常告诉你问题所在。您的 Client 类不可序列化。要序列化一个对象，它引用的所有对象(等等，可传递的)也需要是可序列化的。如果您不希望它被序列化，您可以将引用标记为 transient。