Writing objects to file while appending [duplicate]

问题

I have created a program which registers members for a library system. To store the data i have used text files and to read/write i implemented serialization.

My problem is when i register one member and try to register another member, the second member records won't get saved. To append writing to the file i used the keyword "true" as well.

Here is what i have done:

//Am writing the object to a file

   public void RegisterMembers(Members object) {
        try{

        FileOutputStream write=new FileOutputStream("Memberships.txt",true);
        ObjectOutputStream writeFile=new ObjectOutputStream(write);

        writeFile.writeObject(object);
        writeFile.flush();
        writeFile.close();

        }catch(Exception e){
              Frame frame=new Frame();
            JOptionPane.showMessageDialog(frame,"Storage file not found");
        }


}


   //Method to read from the file
   public void readMemberships() throws FileNotFoundException, IOException,   ClassNotFoundException{
             Person object;


                FileInputStream read=new FileInputStream("Memberships.txt");
                ObjectInputStream readFile=new ObjectInputStream(read);

               object=(Person)readFile.readObject();

            System.out.println(object);



    }

//Here is a piece of code which is in the gui frame which i implemented
       Members newMember=new   Members(firstName,initials,birthDay,birthMonth,birthYear,Gender,memberid,address,tele,membershipType,paymentType);

       newMember.RegisterMembers(newMember);  //calls the 2 methods

       newMember.readMemberships();

What seems to be the error here? I want it to append when writing.

Thank you for your time.

回答1:

I think that the topic I created (It is solved now) is what you are looking for.

"You can't append to an existing file created with an ObjectOutputStream, at least not without effort. There is a trick somewhere about extending ObjectOutputStream and overriding the `writeStreamHeader() method so as not to write the stream header the second time (...)" - answered by EJP

Please have look for my topic here: