Redis Watcher

Redis Watcher is a Redis watcher for jCasbin.

Installation

For Maven

<dependency>
    <groupId>org.casbin</groupId>
    <artifactId>jcasbin-redis-watcher</artifactId>
    <version>1.0-SNAPSHOT</version>
</dependency>

Publish and Subscribe

Please learn redis publish and subscribe first.

Creating a redis-watcher will create a new thread for subscribing to the topic (Channel) of redis. Multiple instances create multiple watchers and corresponding threads subscribe to the same topic. When one of the instances executes the action of the update policy (such as e.addPolicy, e.removePolicy ...), it will send a message to the topic, and then other instances that have subscribed to the topic will receive the notification and execute the updateCallback method. The default updateCallback is to call e.LoadPolicy, which is the reload policy. (When you call e.setWatcher(redisWatcher), it will set default updateCallback)

Simple Example

if you have two casbin instances A and B

A: Producer

String redisTopic="jcasbin-topic";
RedisWatcher redisWatcher = new RedisWatcher("127.0.0.1",6379, redisTopic);
// Support for connecting to redis with timeout and password
// RedisWatcher redisWatcher = new RedisWatcher("127.0.0.1",6379, redisTopic, 2000, "foobared");

Enforcer enforcer = new SyncedEnforcer("examples/rbac_model.conf", "examples/rbac_policy.csv");
enforcer.setWatcher(redisWatcher);

// The following code is not necessary and generally does not need to be written unless you understand what you want to do
/*
Runnable updateCallback = ()->{
    // Custom behavior
};

redisWatcher.setUpdateCallback(updateCallback);
*/

// Modify policy, it will notify B
enforcer.addPolicy(...);

B: Consumer

String redisTopic="jcasbin-topic";
RedisWatcher redisWatcher = new RedisWatcher("127.0.0.1",6379, redisTopic);

Enforcer enforcer = new SyncedEnforcer("examples/rbac_model.conf", "examples/rbac_policy.csv");
enforcer.setWatcher(redisWatcher);
// B set watcher and subscribe redisTopic, then it will receive the notification of A, and then call LoadPolicy to reload policy

Getting Help

• jCasbin
• jedis

License

This project is under Apache 2.0 License. See the LICENSE file for the full license text.