/**
* Listen to events coming from all grid nodes.
*
* @throws GridException If failed.
*/
private static void remoteListen() throws GridException {
Grid g = GridGain.grid();
GridCache<Integer, String> cache = g.cache(CACHE_NAME);
// Register remote event listeners on all nodes running cache.
GridFuture<?> fut =
g.forCache(CACHE_NAME)
.events()
.remoteListen(
// This optional local callback is called for each event notification
// that passed remote predicate filter.
new GridBiPredicate<UUID, GridCacheEvent>() {
@Override
public boolean apply(UUID nodeId, GridCacheEvent evt) {
System.out.println();
System.out.println(
"Received event [evt="
+ evt.name()
+ ", key="
+ evt.key()
+ ", oldVal="
+ evt.oldValue()
+ ", newVal="
+ evt.newValue());
return true; // Return true to continue listening.
}
},
// Remote filter which only accepts events for keys that are
// greater or equal than 10 and if local node is primary for this key.
new GridPredicate<GridCacheEvent>() {
/** Auto-inject grid instance. */
@GridInstanceResource private Grid g;
@Override
public boolean apply(GridCacheEvent evt) {
Integer key = evt.key();
return key >= 10
&& g.cache(CACHE_NAME).affinity().isPrimary(g.localNode(), key);
}
},
// Types of events for which listeners are registered.
EVT_CACHE_OBJECT_PUT,
EVT_CACHE_OBJECT_READ,
EVT_CACHE_OBJECT_REMOVED);
// Wait until event listeners are subscribed on all nodes.
fut.get();
int keyCnt = 20;
// Generate cache events.
for (int i = 0; i < keyCnt; i++) cache.putx(i, Integer.toString(i));
}
/**
* Executes example.
*
* @param args Command line arguments, none required.
* @throws GridException If example execution failed.
*/
public static void main(String[] args) throws Exception {
try (Grid grid = GridGain.start("examples/config/example-cache.xml")) {
System.out.println();
System.out.println(">>> Events API example started.");
// Listen to events happening on local node.
localListen();
// Listen to events happening on all grid nodes.
remoteListen();
// Wait for a while while callback is notified about remaining puts.
Thread.sleep(1000);
}
}
/**
* Listen to events that happen only on local node.
*
* @throws GridException If failed.
*/
private static void localListen() throws GridException {
Grid g = GridGain.grid();
// Register event listener for all local task execution events.
g.events()
.localListen(
new GridPredicate<GridEvent>() {
@Override
public boolean apply(GridEvent evt) {
GridTaskEvent taskEvt = (GridTaskEvent) evt;
System.out.println();
System.out.println(
"Git event notification [evt="
+ evt.name()
+ ", taskName="
+ taskEvt.taskName()
+ ']');
return true;
}
},
EVTS_TASK_EXECUTION);
// Generate task events.
g.compute()
.withName("example-event-task")
.run(
new GridRunnable() {
@Override
public void run() {
System.out.println();
System.out.println("Executing sample job.");
}
})
.get();
}
