Redisson是使用Redis实现分布式任务执行和调度的Java开源项目，它是通过标准JDK的ExecutorService和ScheduledExecutorService API实现的，被提交的任务在Redisson节点服务器上运行，它们共同连接同样的Redis数据库。
Redisson节点
Redisson节点是标准的Java应用，唯一目标就是执行被提交的任务，每个Redisson节点可以看成是分布式环境中远程worker。
它也可以通过一个Redisson实例在主要应用中跨多个进程。
所有任务都是动态加载，这样你不必将任务放在classpath或者每次任务改变时重启。
任务
一个任务应该实现接口java.util.concurrent.Callable or java.lang.Runnable interface.
下面是Callable 接口实现案例：
public class CallableTask implements Callable {
@RInject
private RedissonClient redissonClient;
private long anyParam;
public CallableTask() { }
public CallableTask(long anyParam) {
this.anyParam = anyParam;
}
@Override
public Long call() throws Exception { // ... } }
下面是Runnable 接口实现：
public class RunnableTask implements Runnable {
@RInject
private RedissonClient redissonClient;
private long anyParam;
public RunnableTask() { }
public RunnableTask(long anyParam) {
this.anyParam = anyParam;
}
@Override
public void run() { // ... } }
任务能够通过构造器赋予参数，一个被提交的任务能够通过@RInject访问Redisson实例。
任务提交执行是通过提交给ExecutorService API，RExecutorService 已经实现了 java.util.concurrent.ExecutorService：
RExecutorService executorService = redisson.getExecutorService("myExecutor");
executorService.submit(new RunnableTask());// or with parameterexecutorService.submit(new RunnableTask(41)); executorService.submit(new CallableTask());// or with parameterexecutorService.submit(new CallableTask(53));
使用 java.util.concurrent.ScheduledExecutorService 递交给调度执行：
RScheduledExecutorService executorService = redisson.getExecutorService("myExecutor");
executorService.schedule(new CallableTask(), 10, TimeUnit.MINUTES);// orexecutorService.schedule(new RunnableTask(), 5, TimeUnit.SECONDS);
executorService.scheduleAtFixedRate(new RunnableTask(), 10, 25, TimeUnit.HOURS);// orexecutorService.scheduleWithFixedDelay(new RunnableTask(), 5, 10, TimeUnit.HOURS);
递交给CRON定时执行，兼容于 Quartz cron 格式：
RScheduledExecutorService executorService = redisson.getExecutorService("myExecutor");
executorService.schedule(new RunnableTask(), CronSchedule.of("10 0/5 * * * ?"));// orexecutorService.schedule(new RunnableTask(), CronSchedule.dailyAtHourAndMinute(10, 5));// orexecutorService.schedule(new RunnableTask(),
CronSchedule.weeklyOnDayAndHourAndMinute(12, 4, Calendar.MONDAY, Calendar.FRIDAY));
任务取消：
Future> f = executorService.schedule(...);
// orFuture> f = executorService.submit(...);
f.cancel(true);
任务取消类似执行Java的线程中断。
下面是将所有值聚合在大的Redis map中，这个过程会花费很长时间：
public class CallableTask implements Callable {
@RInject
private RedissonClient redissonClient;
@Override
public Long call() throws Exception {
RMap map = redissonClient.getMap("myMap");
Long result = 0;
for (Integer value : map.values()) {// check if task has been canceledif (Thread.currentThread().isInterrupted()) {// task has been canceledreturn null;
}
result += value;
}
return result;
} }
提交任务给ExecutorService是同步的，处理结果接受可以使用异步的，这是通过标准java.util.concurrent.Future实现。Redisson也提供一系列方法异步提交任务：RExecutorServiceAsync.*Async。
RScheduledExecutorService executorService = redisson.getExecutorService("myExecutor");
RFuture future = executorService.submitAsync(new CallableTask());// orRScheduledFuture future = executorService.scheduleAsync(new RunnableTask(), 5, TimeUnit.SECONDS);// orRScheduledFuture future = executorService.scheduleAtFixedRateAsync(new RunnableTask(), 10, 25, TimeUnit.HOURS);
future.addListener(new FutureListener() {
public void operationComplete(Future f) {// ... }});// cancel task by idString taskId = future.getId();// ...executorService.cancelScheduledTask(taskId);
Redisson构成了对另外一个分布式内存数据网格产品Hazelcast的挑战。
项目地址：