Batch Authorizer for Pusher Java Client.

BatchAuthorizer.java

class BatchAuthorizer extends HttpAuthorizer {

    private final Collection<String> channelsToSub;

    private Map<String, JSONObject> cachedAuthMap = new HashMap<>();

    /**
     * We need the socket id to know when to refresh the batch auth data
     */
    private String authSocketId = "";

    /**
     * An Optional string collection to manage the batch mechanism of doing pusher channel auth
     *
     * @param endPoint      The endpoint for the pusher auth session JSON string
     * @param channelsToSub the list of channels to subscribe to
     */
    public BatchAuthorizer(String endPoint, Collection<String> channelsToSub) {
        super(endPoint);
        this.channelsToSub = channelsToSub;
    }

    @Override
    public String authorize(String channelName, String socketId) throws AuthorizationFailureException {
        batchAuthorize(socketId);
        /* If we don't have a cached Auth String after this we fallback to old method */
        if (!cachedAuthMap.containsKey(channelName)) {
            String authString = super.authorize(channelName, socketId);
            try {
                cachedAuthMap.put(channelName, new JSONObject(authString));
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
        return cachedAuthMap.get(channelName).toString();
    }

    private void batchAuthorize(String socketId) {
        /**
         * If the socket ID matches the authorized socket ID, then we have nothing to do
         * This also works in the scenario of connection changes because the socket ID will
         * automatically change and Pusher will trigger the re-auth
         */
        if (this.authSocketId.equals(socketId))
            return;

        /** Since we are going to re-auth anyways we clear our cache */
        cachedAuthMap.clear();
        /* If not let's fire the authSocket ID */
        // Download your auth information here from your web server API & put it into cachedAuthMap
        // example:-
        // cachedAuthMap.put(channelName, new JSONObject(authString));
        // I am using JSON throughout you can use anything else.
        this.authSocketId = socketId;
    }
}