readObject function in Serializable not called when enable proguard

Question

I make a PersistentCookieStore for android app with:

decodeCookie function:

protected HttpCookie decodeCookie(String cookieString) {
    byte[] bytes = hexStringToByteArray(cookieString);
    ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(bytes);
    HttpCookie cookie = null;
    try {
        MyObjectInputStream objectInputStream = new MyObjectInputStream(byteArrayInputStream);
        cookie = ((SerializableHttpCookie) objectInputStream.readObject()).getCookie();
    } catch (IOException e) {
        Log.d(LOG_TAG, "IOException in decodeCookie", e);
    } catch (ClassNotFoundException e) {
        Log.d(LOG_TAG, "ClassNotFoundException in decodeCookie", e);
    }

    return cookie;
}

Custom ObjectInputStream class:

class MyObjectInputStream extends ObjectInputStream {

    public MyObjectInputStream(InputStream input) throws StreamCorruptedException, IOException {
        super(input);
    }

    protected ObjectStreamClass readClassDescriptor() throws IOException, ClassNotFoundException {
        ObjectStreamClass os = super.readClassDescriptor();
        if (os.getName().equals(SerializableHttpCookie.class.getName()))
            os = ObjectStreamClass.lookup(SerializableHttpCookie.class);
        return os;
    }
}

And here is SerializableHttpCookie class:

public class SerializableHttpCookie implements Serializable {
    private static final long serialVersionUID = 6374381323722046732L;

    private transient final HttpCookie cookie;
    private transient HttpCookie clientCookie;

    public SerializableHttpCookie(HttpCookie cookie) {
        this.cookie = cookie;
    }

    public HttpCookie getCookie() {
        HttpCookie bestCookie = cookie;
        if (clientCookie != null) {
            bestCookie = clientCookie;
        }
        return bestCookie;
    }

    private void writeObject(ObjectOutputStream out) throws IOException {
        out.writeObject(cookie.getName());
        out.writeObject(cookie.getValue());
        out.writeObject(cookie.getComment());
        out.writeObject(cookie.getCommentURL());
        out.writeObject(cookie.getDomain());
        out.writeLong(cookie.getMaxAge());
        out.writeObject(cookie.getPath());
        out.writeObject(cookie.getPortlist());
        out.writeInt(cookie.getVersion());
        out.writeBoolean(cookie.getSecure());
        out.writeBoolean(cookie.getDiscard());
    }

    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
        String name = (String) in.readObject();
        String value = (String) in.readObject();
        clientCookie = new HttpCookie(name, value);
        clientCookie.setComment((String) in.readObject());
        clientCookie.setCommentURL((String) in.readObject());
        clientCookie.setDomain((String) in.readObject());
        clientCookie.setMaxAge(in.readLong());
        clientCookie.setPath((String) in.readObject());
        clientCookie.setPortlist((String) in.readObject());
        clientCookie.setVersion(in.readInt());
        clientCookie.setSecure(in.readBoolean());
        clientCookie.setDiscard(in.readBoolean());
    }
}

when debug everything look good, readObject is call so that clientCookie not null, decodeCookie return not null but when I enable proguard I see that after call readClassDescriptor readObject never called. So that decodeCookie return null.

Please help me fix this bug.

Answer 1

Try add:

-keepnames class * implements java.io.Serializable
-keepclassmembers class * implements java.io.Serializable {
    static final long serialVersionUID;
    private static final java.io.ObjectStreamField[] serialPersistentFields;
    !static !transient <fields>;
    private void writeObject(java.io.ObjectOutputStream);
    private void readObject(java.io.ObjectInputStream);
    java.lang.Object writeReplace();
    java.lang.Object readResolve();
}

to proguard.