WebPush

A Web Push library for Java 7. Supports payloads and VAPID.

Installation

For Gradle, add the following dependency to build.gradle:

compile group: 'nl.martijndwars', name: 'web-push', version: '3.0.0'

For Maven, add the following dependency to pom.xml:

<dependency>
    <groupId>nl.martijndwars</groupId>
    <artifactId>web-push</artifactId>
    <version>3.0.0</version>
</dependency>

This library depends on BouncyCastle, which acts as a Java Cryptography Extension (JCE) provider. BouncyCastle's JARs are signed, and depending on how you package your application, you may need to include BouncyCastle yourself as well.

Building

To build the project yourself, clone this repository and build a run:

./gradlew assemble

To build a fat JAR in build/libs (e.g. to use the CLI):

./gradlew shadowJar

Usage

This library is meant to be used as a Java API. However, it also exposes a CLI to easily generate a VAPID keypair and send a push notification.

CLI

A command-line interface is available to easily generate a keypair (for VAPID) and to try sending a notification.

Usage: <main class> [command] [command options]
  Commands:
    generate-key      Generate a VAPID keypair
      Usage: generate-key

    send-notification      Send a push notification
      Usage: send-notification [options]
        Options:
          --subscription
            A subscription in JSON format.
          --publicKey
            The public key as base64url encoded string.
          --privateKey
            The private key as base64url encoded string.
          --payload
            The message to send.
            Default: Hello, world!
          --ttl
            The number of seconds that the push service should retain the message.

For example, to generate a keypair and output the keys in base64url encoding:

$ java -jar build/libs/web-push-3.0.0-all.jar generate-key
PublicKey:
BGgL7I82SAQM78oyGwaJdrQFhVfZqL9h4Y18BLtgJQ-9pSGXwxqAWQudqmcv41RcWgk1ssUeItv4-8khxbhYveM=

PrivateKey:
ANlfcVVFB4JiMYcI74_h9h04QZ1Ks96AyEa1yrMgDwn3

Use the public key in the call to pushManager.subscribe to get a subscription. Then, to send a notification:

$ java -jar build/libs/web-push-3.0.0-all.jar send-notification \
  --subscription="{'endpoint':'https://fcm.googleapis.com/fcm/send/fH-M3xRoLms:APA91bGB0rkNdxTFsXaJGyyyY7LtEmtHJXy8EqW48zSssxDXXACWCvc9eXjBVU54nrBkARTj4Xvl303PoNc0_rwAMrY9dvkQzi9fkaKLP0vlwoB0uqKygPeL77Y19VYHbj_v_FolUlHa','keys':{'p256dh':'BOtBVgsHVWXzwhDAoFE8P2IgQvabz_tuJjIlNacmS3XZ3fRDuVWiBp8bPR3vHCA78edquclcXXYb-olcj3QtIZ4=','auth':'IOScBh9LW5mJ_K2JwXyNqQ=='}}" \
  --publicKey="BGgL7I82SAQM78oyGwaJdrQFhVfZqL9h4Y18BLtgJQ-9pSGXwxqAWQudqmcv41RcWgk1ssUeItv4-8khxbhYveM=" \
  --privateKey="ANlfcVVFB4JiMYcI74_h9h04QZ1Ks96AyEa1yrMgDwn3" \
  --payload="Hello, lovely world!"

Proxy

If you are behind a corporate proxy you may need to specify the proxy host. This library respects Java's Network Properties, which means that you can pass https.proxyHost and http.proxyPort when invoking java, e.g. java -Dhttp.proxyHost=proxy.corp.com -Dhttp.proxyPort=80 -Dhttps.proxyHost=proxy.corp.com -Dhttps.proxyPort=443 -jar ....

API

First, create an instance of the push service:

pushService = new PushService(...);

Then, create a notification based on the user's subscription:

Notification notification = new Notification(...);

To send a push notification:

pushService.send(notification);

Use sendAsync instead of send to get a Future<HttpResponse>:

pushService.sendAsync(notification);

See doc/UsageExample.md for detailed usage instructions. If you plan on using VAPID, read doc/VAPID.md.

Testing

Our integration tests use Web Push Testing Service (WPTS) to automate browser interaction. To install WPTS:

npm install web-push-testing-service -g

Then, to start WPTS:

web-push-testing-service start wpts

Finally, to run all tests:

./gradlew test

FAQ

Why does encryption take multiple seconds?

There may not be enough entropy to generate a random seed, which is common on headless servers. There exist two ways to overcome this problem:

Install haveged, a "random number generator that remedies low-entropy conditions in the Linux random device that can occur under some workloads, especially on headless servers." This tutorial explains how to install haveged on different Linux distributions.
Change the source for random number generation in the JVM from /dev/random to /dev/urandom. This page offers some explanation.

Credit

To give credit where credit is due, the PushService is mostly a Java port of marco-c/web-push. The HttpEce class is mostly a Java port of martinthomson/encrypted-content-encoding.

Resources

For PHP, see web-push-libs/web-push-php
For NodeJS, see web-push-libs/web-push
For Python, see web-push-libs/pywebpush

defenderhhhh / webpush-java