Java套接字：接收错误的布尔值

Question

I have a client/server architecture that sends class-instances via sockets.

In one class I have a boolean:

public class Survey implements Serializable {
    private static final long serialVersionUID = -1156493488498723461L;
    private boolean isExpired;

    public Survey() {
        this.isExpired = false;
    }

    public void markAsExpired() {
        this.isExpired = true;
    }

    public boolean isExpired() {
        return isExpired;
    }
}

The part where I send the packet:

survey.markAsExpired();
HashMap<Header, Object> packet = new HashMap<Header, Object>();
packet.put(header, survey);

System.out.println(survey.isExpired()); // prints true
try {
    socketOutput.writeObject(packet);
    socketOutput.flush();
} catch (IOException e) {
    e.printStackTrace();
}

When I send that class with the boolean set to true (see above), the client always receives it as false.

Where does this come from?

Answer 1

I could solve the problem by sending a deep copy instead of the object itself. Workaround but worked.