Re: Safety Of Non-Synchronized Collections

Steve wrote, quoted or indirectly quoted someone who said :


Your rules of thumb will work most of the time. Someone might think
of a pathological case, but I can't offhand.

I always use StringBuilder in preference to StringBuffer except when I
am writing for very old versions of Java (as in Wassup). I am also

forced to use it in Regex search/replace which uses the legacy
StringBuffer class.

But actually I nearly always use FastCat which is much more memory
efficient than StringBuilder. You have to estimate how many pieces
you will join, not their total length. That is much easier.

see http://mindprod.com/products.html#FASTCAT

You almost never share a StringBuilder between threads. It is
invariably referenced by a local variable. So the need for thread safe
code rarely comes up.

I wish there were an optimisation possible in such code. It composes a
char array which it then converts to a String. In theory it should be
possible to create the String from that array which is no longer
needed without making a copy. The problem is making sure there are no
references to the array. You build a proto string containing a char
array, copy strings into in, then convert it into a real string. Such
code could prevent an references to the array from being created.