# Class: com.pnfsoftware.jeb.util.concurrent.WeakConcurrentMap A thread\-safe map with weak keys. Entries are based on a key's system hash code and keys are considered equal only by reference equality. This class does not implement the [java.util.Map](java.util.Map) interface because this implementation is incompatible with the map contract. While iterating over a map's entries, any key that has not passed iteration is referenced non\-weakly. ## Constructor: WeakConcurrentMap - parameter: `cleanerThread`, type: `boolean` Description: Create a weak\-key concurrent map. parameter: cleanerThread: `true` if a thread should be started that removes stale entries. ## Field: target Type: `java.util.concurrent.ConcurrentMap,V>` Description: Backing map used to store weak keys and their associated values. ## Method: approximateSize - return type: `int` Description: Returns the approximate size of this map where the returned number is at least as big as the actual number of entries. return: the approximate size of this map ## Method: clear Description: Clears the entire map. ## Method: containsKey - parameter: `key`, type: `K` - return type: `boolean` Description: parameter: key: The key of the entry. return: `true` if the key already defines a value. ## Protected Method: defaultValue - parameter: `key`, type: `K` - return type: `V` Description: Creates a default value. There is no guarantee that the requested value will be set as a once it is created in case that another thread requests a value for a key concurrently. parameter: key: The key for which to create a default value. return: The default value for a key without value or `null` for not defining a default value. ## Method: expungeStaleEntries Description: Cleans all unused references. ## Method: get - parameter: `key`, type: `K` - return type: `V` Description: parameter: key: The key of the entry. return: The value of the entry or the default value if it did not exist. ## Method: getCleanerThread - return type: `java.lang.Thread` Description: return: The cleaner thread or `null` if no such thread was set. ## Method: iterator - return type: `java.util.Iterator>` Description: Iterate over live entries. return: an iterator over entries whose keys have not been collected ## Method: put - parameter: `key`, type: `K` - parameter: `value`, type: `V` - return type: `V` Description: parameter: key: The key of the entry. parameter: value: The value of the entry. return: The previous entry or `null` if it does not exist. ## Method: remove - parameter: `key`, type: `K` - return type: `V` Description: parameter: key: The key of the entry. return: The removed entry or `null` if it does not exist. ## Method: run Description: Run the cleaner loop until interrupted, then clear the map.