java - 将客户端对象发送到服务器时出错

Question

我无法通过客户端将对象发送到服务器，因为当我运行客户端时，服务器程序崩溃，导致出现“连接重置”错误

这是客户端:

    public class Client {

    public static void main(String[] args) throws IOException, SQLException, ClassNotFoundException{
        Socket s = new Socket("192.168.1.3", 4444);
        ObjectOutputStream oos = new ObjectOutputStream(s.getOutputStream());

        Group g = new Group("EXAMPLE");
        String command = "ADD_GROUP";
        System.out.println("Sending: " + command);
        oos.writeUTF(command);
        oos.flush();
        oos.writeObject(g);
        oos.flush();
        s.close();
     }

}

这是服务器:

    public class Server{

    public static void main(String[] args) throws IOException, SQLException, ClassNotFoundException, ParseException
    {

       ServerSocket server = new ServerSocket(4444);

       System.out.println("Waiting for clients to connect...");

       SimpleDataSource.init("database.properties");
       Network net = new Network();

       while (true)
       {
          Socket s = server.accept();
          InetAddress clientAddress = s.getInetAddress();
          System.out.println("Incoming connection from: " + clientAddress.getHostName() + "[" + clientAddress.getHostAddress() + "]");

          ServiceClass service = new ServiceClass(s,net);
          service.doService();

       }
    }
}

这是 ServiceClass 类:

    public class ServiceClass{

    private Socket s;
    private Network net;

    public ServiceClass(Socket s, Network net){
        this.s = s;
        this.net = net;
    }

    public void doService() throws IOException, SQLException, ClassNotFoundException, ParseException
    {
       ObjectInputStream ois = new ObjectInputStream(s.getInputStream());

       while(true){

            String line = (String) ois.readUTF();
            System.out.println("Received: " + line);

            if(line.equals("ADD_GROUP")){
                Group group = (Group) ois.readObject();
                net.addGroup(group);
            }
        }
    }
}

当我运行服务器时，它等待客户端连接，当我运行客户端程序时，服务器崩溃，出现此错误:

    Waiting for clients to connect...
Incoming connection from: UNKNOWN_DEVICE[192.168.1.3]
Received: ADD_GROUP
Error: Group already exists
Exception in thread "main" java.io.EOFException
    at java.io.DataInputStream.readUnsignedShort(DataInputStream.java:340)
    at java.io.ObjectInputStream$BlockDataInputStream.readUnsignedShort(ObjectInputStream.java:2808)
    at java.io.ObjectInputStream$BlockDataInputStream.readUTF(ObjectInputStream.java:2864)
    at java.io.ObjectInputStream.readUTF(ObjectInputStream.java:1072)
    at social_network.ServiceClass.doService(ServiceClass.java:35)
    at social_network.Server.main(Server.java:39)
Java Result: 1

这有什么问题吗？

Answer 1

客户端没有关闭套接字，因此当服务器尝试读取不存在的第二个字符串时，服务器可以获得连接重置而不是 EOFException。

当您修复该问题时，EOFException 意味着没有任何内容可供读取。这不是问题。你只要捕获它，然后打破它。