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This project is work in progress. if you are interested in contributing or otherwise have input please touch base via github

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about

q is a queueing toolkit. the idea is to provide a universal application programming interface that can be used throughout the entire application development lifecycle without the need to commit to a specific queueing technology or to set up complex queueing environments where such are not required. you can think of it as an ORM for queueing.

q runs on multiple back-ends and has bindings to many programing languages. and so, while during development you will most likely run it in-memory and let it clear when the process dies, you may choose a redis back-end on your test environment and running dedicated servers backed by rabbitMQ, amazon SQS or some other enterprise queueing system on production.

see more about the core library at https://github.com/tomerd/q

q bindings for java

q bindings for java uses JNI to bind to q's native API. q is represented by the Q class which exposes a simple API:

• getVersion(): returns the version of q

• connect(config): connects to the library and initialized a connection to the backend specified by the config param. see further documentation on backends at the core library.

• disconnect: disconnect from the library. no further calls can be made after this.

• post(queue, data): posts a job to a named queue (aka channel).

• post(queue, uid, data): posts a uniquely identified job to a named queue (aka channel). useful if you are planning to update the job.

• postAt(queue, data, run_at): posts a job to a named queue (aka channel) in a future date.

• postAt(queue, uid, data, run_at): posts a uniquely identified job to a named queue (aka channel) in a future date. useful if you are planning to rescheduling the job.

• reschedule(uid, run_at): reschedule the job identified by uid to a new target date.

• cancel(uid): cancel a scheduled jobs.

• worker(queue, Worker): register a worker for a named queue (aka channel). a worker is implemented by implementing the Worker interface which includes a single "perform" method. the worker will start receiving jobs immediately.

• observer(queue, Observer): register an observer for a named queue (aka channel). an observer is implemented by implementing the Observer interface which includes a single "perform" method. the observer will start receiving jobs immediately. the difference between an observer and a worker is that the observer is passive in nature and as such is notified only after a worker has completed the job successfully.

• drop: careful, drops all queues! useful in development scenarios when you need to flush the entire queue system.

important

• qlib does not build with the JNI headers by default. to enable Java support you must build it with the "--with-java" flag

    autoreconf -i && automake
    ./configure --with-java
    make && make install
  

• make sure to set java.library.path to where qlib is installed (normally /usr/local/lib). otherwise the JVM will not be able to find the q library.

usage example

Q q = new Q();
String v = q.getVersion();
System.out.println("using q version " +  v);

q.connect("{ \"driver\": \"redis\", \"host\": \"127.0.0.1\" }");

q.worker("channel1", new Worker()
{
    public void perform(String data)
    {
        System.out.println("java worker1 received '" + data + "'");
    }
});

q.post("channel1", "java 1");
q.postAt("channel1", "java 2", System.currentTimeMillis() + 5 * 1000);
q.post("channel1", "java 3");
q.postAt("channel1", "java 4", System.currentTimeMillis() + 3 * 1000);
q.post("channel1", "java 5");
q.postAt("channel1", "java 6", System.currentTimeMillis() + 3 * 1000);

Thread.sleep(7*1000);

q.disconnect();
System.out.println("done");