This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
I call Random.nextLong() and HashMap.toString() from code that is accessed by multiple threads. Should calls to these methods be synchronized? I believe Random is threadsafe. I know that HashMap is not, but I'm not sure about toString().
This question may be better suited to the Threads forum, but since the issue came up while working on the SCJD exam I'll post it here.