SignalClient.java

// Copyright (c) P. Taylor Goetz (ptgoetz@gmail.com)

package ch.epfl.data.squall.components.signal_components.storm;

import org.apache.storm.curator.framework.CuratorFramework;
import org.apache.storm.curator.framework.CuratorFrameworkFactory;
import org.apache.storm.curator.retry.RetryOneTime;
import org.apache.storm.zookeeper.data.Stat;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class SignalClient {

    private static final Logger LOG = LoggerFactory
	    .getLogger(SignalClient.class);

    private CuratorFramework client = null;
    private String name;

    public SignalClient(String zkConnectString, String name) {
	this.name = name;
	this.client = CuratorFrameworkFactory.builder()
		.namespace("storm-signals").connectString(zkConnectString)
		.retryPolicy(new RetryOneTime(500)).build();
	LOG.debug("created Curator client");
    }

    public void start() {
	this.client.start();
    }

    public void close() {
	this.client.close();
    }

    public void send(byte[] signal) throws Exception {
	Stat stat = this.client.checkExists().forPath(this.name);
	if (stat == null) {
	    String path = this.client.create().creatingParentsIfNeeded()
		    .forPath(this.name);
	    LOG.info("Created: " + path);
	}
	this.client.setData().forPath(this.name, signal);
    }

    /**
     * @param args
     */
    public static void main(String[] args) throws Exception {
	SignalClient sc = new SignalClient("localhost:2000",
		"test-signal-spout");
	sc.start();
	try {
	    sc.send("Hello Signal Spout!".getBytes());
	} finally {
	    sc.close();
	}
    }

}