YGC time increasing suddenly

[Bernd Eckenfels]

Am 21.12.2013, 17:15 Uhr, schrieb Luciano Molinari <lucmolinari at gmail.com>:
> I noticed that many Strings in the heap are equals..shouldn't JVM keep
> only different Strings and re-use the equals?

When a string is interned (all constants in your classes are interned)  
then there is only one instance for a string. However if you (or a  
library) construct a new string from bytes/characters then it will not be  
automatically interned and therefore created with multiple instances  
(basically if you use "new String" you get what you ask for :)

You can use .intern() on a String to get its unique instance, but be sure  
to do this only for the most common/often used strings. This does  
essentially a hash lookup, so it is most often not a good idea to do it  
(unless you know you keep them around for long and/or equal() them very  
often. (For example it sometimes make sense to intern() all element names  
of Dom Trees but not the (too many different) values).

Gruss
Bernd
-- 
http://bernd.eckenfels.net