PUSHY APNS - AnnotatedSocketException: Network is unreachable: api.sandbox.push.apple.com/2620

Question

I use the PUSHY library 0.15.2 version to send push notifications to ios devices using Spring boot.

The APNS code look like this -

ApnsClientBuilder clientBuilder = new ApnsClientBuilder();
            clientBuilder.setApnsServer(ApnsClientBuilder.DEVELOPMENT_APNS_HOST);
            clientBuilder.setConnectionTimeout(Duration.ofMillis(60000));
            File file = new File(getClass().getClassLoader().getResource("zzzzz").getFile());
            clientBuilder.setClientCredentials(file, "yyyyy");

            apnsClient = clientBuilder.build();

            ApnsPayloadBuilder payloadBuilder = new SimpleApnsPayloadBuilder();
            payloadBuilder.setAlertTitle("xxxx");
            payloadBuilder.setAlertBody("This is test message");

            SimpleApnsPushNotification pushNotification = new SimpleApnsPushNotification(messageDto.getDeviceId(),
                    "com.np.gotprint", payloadBuilder.build());
            apnsClient.sendNotification(pushNotification).get();
            
            System.out.println("send successfully");

but I am getting the following error -

Caused by: io.netty.channel.AbstractChannel$AnnotatedSocketException: Network is unreachable: api.sandbox.push.apple.com/2620:149:208:304:0:0:0:1f:443
Caused by: java.net.SocketException: Network is unreachable
    at sun.nio.ch.Net.connect0(Native Method)
    at sun.nio.ch.Net.connect(Net.java:454)
    at sun.nio.ch.Net.connect(Net.java:446)
    at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:648)
    at io.netty.util.internal.SocketUtils$3.run(SocketUtils.java:83)
    at io.netty.util.internal.SocketUtils$3.run(SocketUtils.java:80)
    at java.security.AccessController.doPrivileged(Native Method)
    at io.netty.util.internal.SocketUtils.connect(SocketUtils.java:80)

Note - When I run the code locally, it works fine, throws an error when I deploy in staging env.

Am I doing something wrong here?

Answer 1

Based on the exception you get

"Network is unreachable: api.sandbox.push.apple.com/2620:149:208:304:0:0:0:1f:443",

it seems that you are attempting to use IPv6 but your network does not support it. You may force IPv4 preference with the following system property.

-Djava.net.preferIPv4Stack=true.