Hazelcast Jet IMap 删除条目
Hazelcast Jet IMap remove entry
我已阅读 Hazelcast Jet 的文档。
我看到可以 add/update IMap 接收器中的条目。
但是我在任何地方都看不到如何从 IMap 中删除条目。
有办法吗?
参见 Sinks.mapWithMerging
,来自 JavaDoc:
/**
* Returns a sink that uses the supplied functions to extract the key
* and value with which to update a Hazelcast {@code IMap}. If the map
* already contains the key, it applies the given {@code mergeFn} to
* resolve the existing and the proposed value into the value to use. If
* the value comes out as {@code null}, it removes the key from the map.
* Expressed as code, the sink performs the equivalent of the following for
* each item:
* <pre>
* K key = toKeyFn.apply(item);
* V oldValue = map.get(key);
* V newValue = toValueFn.apply(item);
* V resolved = (oldValue == null)
* ? newValue
: mergeFn.apply(oldValue, newValue);
* if (value == null)
* map.remove(key);
* else
* map.put(key, value);
* </pre>
...
我已阅读 Hazelcast Jet 的文档。
我看到可以 add/update IMap 接收器中的条目。 但是我在任何地方都看不到如何从 IMap 中删除条目。
有办法吗?
参见 Sinks.mapWithMerging
,来自 JavaDoc:
/**
* Returns a sink that uses the supplied functions to extract the key
* and value with which to update a Hazelcast {@code IMap}. If the map
* already contains the key, it applies the given {@code mergeFn} to
* resolve the existing and the proposed value into the value to use. If
* the value comes out as {@code null}, it removes the key from the map.
* Expressed as code, the sink performs the equivalent of the following for
* each item:
* <pre>
* K key = toKeyFn.apply(item);
* V oldValue = map.get(key);
* V newValue = toValueFn.apply(item);
* V resolved = (oldValue == null)
* ? newValue
: mergeFn.apply(oldValue, newValue);
* if (value == null)
* map.remove(key);
* else
* map.put(key, value);
* </pre>
...