Hi,
I tested your code and looks like it worked fine.
However, you also can try to use next method:
https://ignite.apache.org/releases/latest/javadoc/org/apache/ignite/IgniteCache.html#getAndPutIfAbsent-K-V-
In this case you can:
1)Check cache.containsKey(key)
2)If true then prepare the default value
3)Run getAndPutIfAbsent(key, defaultValue)
If another client was able to put the value during current prepare the
default then you will get that value, otherwise default value will be
returned.
BR,
Andrei
8/7/2019 12:08 PM, Yohan Fernando пишет:
I'm trying to write a transaction-safe way of performing a lazy load
of an object from the database if it doesnt exist. However as
IgniteCache doesn't have the equivalent of HashMap.computeIfAbsent,
I'm trying to use the IgniteCache.lock method to achieve this.
The question is whether IgniteCache.lock will lock the cache for that
key even if <b>the key does not yet exist in the cache</b>.
Following is the example code,
public GridOrder getOrder(OrderKey key) {
Lock orderKeyLock = cache.lock(key);
try {
orderKeyLock.lock();
if (!cache.containsKey(key)) {
GridOrder order = loadOrderFromDb(key);
if ( order == null) {
throw new IllegalStateException("Key " + key + "
not in Order Cache or in Database DB Name ");
}
cache.put(key,order);
}
return cache.get(key);
} finally {
orderKeyLock.unlock();
}
}
Alternatively, is there a better way to achieve this?
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