Question

I’m having some trouble with sending an Object from my Android app to my Java application.
I have a serializable class that’s exactly the same.

It works perfectly when I send the object from one java appliction to another one using this code on the receiver side:

@Override
public void run() {
    super.run();
    while(true){
        try{
            if(datagramSocket!=null)datagramSocket.close();
            datagramSocket = new DatagramSocket(PORT);
            buffer = new byte[4096];
            inPacket = new DatagramPacket(buffer, buffer.length);
            datagramSocket.receive(inPacket);

            InetAddress clientAddress = inPacket.getAddress();
            int clientPort = inPacket.getPort();

            ByteArrayInputStream bais = new ByteArrayInputStream(buffer);
            ObjectInputStream ois = new ObjectInputStream(new BufferedInputStream(bais));
            Song song = (Song) ois.readObject();
            song.setClientIP(inPacket.getAddress());
            dc.addSong(song);
            datagramSocket.close();

        }catch (IOException e) {
            System.out.println("IOException on receiving song: " + e);
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

but when I try to do the same in android (so sending the Song-object from android to java) I’m getting a ClassCastException:

[Lcom.audiobuddy.serializables.Song; cannot be cast to com.audiobuddy.serializables.Song

First I thought it was because the package name was different, so I changed it on both sides to “com.audiobuddy.serializables”. But I look at my error, the Android app, changes the package adding “[L” in front and “;” in the back…

On both sides the Song-classes have the same serialVersionUID

Answer 1

The error message says that you try to cast Song[] ([L(...)Song means an array of Song) to a Song.

You should probably change your ois.readObject();-line with something like this:

Song[] songs = (Song[]) ois.readObject();
Song song = songs[0];