public static byte[]objectToByte(Object object)
    {
        byte[] bytes = null;
        try  {
            //object to bytearray
            ByteArrayOutputStream bo = new ByteArrayOutputStream();
            ObjectOutputStream oo = new ObjectOutputStream(bo);
            oo.writeObject(object);

            bytes = bo.toByteArray();

            bo.close();
            oo.close();
        }
        catch(Exception e) {
            e.printStackTrace();
        }
        return bytes;
    }

public static Object byteToObject(byte[] bytes) throws Exception
    {
        java.lang.Object obj = null;
        //bytearray to object
        ByteArrayInputStream bi = new ByteArrayInputStream(bytes);
        ObjectInputStream oi = new ObjectInputStream(bi);

        obj = oi.readObject();

        bi.close();
        oi.close();
        return obj;

    }

public class Message implements   Serializable{
    
    String sendName;
    String receiveName;
    int command;
    Date sendDate;
    Object content;
    
    public Message()
    {
        
    }
    
    public Message(String inSendName,String inReceiveName,int inCommand,Date inSendDate,Object inContent)
    {
        this.setSendName(inSendName);
        this.setReceiveName(inReceiveName);
        this.setCommand(inCommand);
        this.setSendDate(inSendDate);
        this.setContent(inContent);
    }//后面get,set就不贴了