StringBuffer is obsolete?

Question

In the book \"Effective Java\", Josh Bloch says that

StringBuffer is largely obsolete and should be replaced by the non-synchronized implementation \'S

Answer 1

It's obsolete in that new code on Java 1.5 should generally use StringBuilder - it's very rare that you really need to build strings in a thread-safe manner, so why pay the synchronization cost?

I suspect code that you see using StringBuffer mostly falls into buckets of:

• Written before Java 1.5
• Written to maintain compatibility with older JDKs
• Written by people who don't know about StringBuilder
• Autogenerated by tools which don't know about StringBuilder