If you need to send apple push notifications to your users, like we do in a secret project mentioned earlier this week, notnoop's java-apns library is a good choice, because its really simple to use and saves you a lot of work.
(I presume that you already know how to get the Tokens of your users and already have a certificate for the push notifications, I only show you how easy the server part can be with this library. If you don't know, read this first: Apple Push Service)
First you have to download the library (or add it in your maven dependencies):
java-apns
The programming part isn't that much so here's how you do it:
public void pushMessage() {
ApnsService service = null;
try {
// get the certificate
InputStream certStream = this.getClass().getClassLoader().getResourceAsStream("your_certificate.p12");
service = APNS.newService().withCert(certStream, "your_cert_password").withSandboxDestination().build();
// or
// service = APNS.newService().withCert(certStream,
// "your_cert_password").withProductionDestination().build();
service.start();
// You have to delete the devices from you list that no longer
//have the app installed, see method below
deleteInactiveDevices(service);
// read your user list
List<User> userList = userDao.readUsers();
for (User user : userList) {
try {
// we had a daily update here, so we need to know how many
//days the user hasn't started the app
// so that we get the number of updates to display it as the badge.
int days = (int) ((System.currentTimeMillis() - user.getLastUpdate()) / 1000 / 60 / 60 / 24);
PayloadBuilder payloadBuilder = APNS.newPayload();
payloadBuilder = payloadBuilder.badge(days).alertBody("some message you want to send here");
// check if the message is too long (it won't be sent if it is)
//and trim it if it is.
if (payloadBuilder.isTooLong()) {
payloadBuilder = payloadBuilder.shrinkBody();
}
String payload = payloadBuilder.build();
String token = user.getToken();
service.push(token, payload);
} catch (Exception ex) {
// some logging stuff
}
}
} catch (Exception ex) {
// more logging
} finally {
// check if the service was successfull initialized and stop it here, if it was
if (service != null) {
service.stop();
}
}
}
private void deleteInactiveDevices(ApnsService service) {
// get the list of the devices that no longer have your app installed from apple
//ignore the ="" after Date here, it's a bug...
Map<String, Date> inactiveDevices = service.getInactiveDevices();
for (String deviceToken : inactiveDevices.keySet()) {
userDao.deleteByDeviceId(deviceToken);
}
}
Now wasn't that an easy one this time?
