[doc]Small modification on the WeakHashMap doc

[David Holmes]

Hi Charles,

On 7/05/2012 1:05 PM, Charles Lee wrote:
> Does anyone interested in this issue?

Interest and time are two different things :)

A shorter form would be:

"If the values in the map do not rely on the map holding strong 
references to them, then one way to deal with this is ...

David

> On 05/03/2012 02:52 PM, Charles Lee wrote:
>> Hi guys,
>>
>> In the Implementation notes of WeakHashMap[1], says:
>>
>> /One way to deal with this is to wrap values themselves within
>> WeakReferences before inserting, as in: m.put(key, new
>> WeakReference(value)), and then unwrapping upon each get./
>>
>> However, it is not concise and a little misleading. Because the value
>> in the WeakReference can be GC'd if there are no strong reference to
>> it. This behaviour surprises some customers.
>> How about add a statement like [2]:
>>
>> /However, as the use of WeakReference in this manner will not prevent
>> value objects from being GC'd, this approach is only useful when
>> entries in the map are not relied upon for keeping the underlying
>> value objects "live"./
>>
>>
>>
>>
>> [1]: http://docs.oracle.com/javase/7/docs/api/java/util/WeakHashMap.html
>> [2]: http://cr.openjdk.java.net/~littlee/7166055/webrev.00/
>> <http://cr.openjdk.java.net/%7Elittlee/7166055/webrev.00/>
>>
>
>