Java – Does Java have a limit on the class name length

There are several differences between HashMap and Hashtable in Java:

1. Hashtable is synchronized, whereas HashMap is not. This makes HashMap better for non-threaded applications, as unsynchronized Objects typically perform better than synchronized ones.

2. Hashtable does not allow null keys or values. HashMap allows one null key and any number of null values.

3. One of HashMap's subclasses is LinkedHashMap, so in the event that you'd want predictable iteration order (which is insertion order by default), you could easily swap out the HashMap for a LinkedHashMap. This wouldn't be as easy if you were using Hashtable.

Since synchronization is not an issue for you, I'd recommend HashMap. If synchronization becomes an issue, you may also look at ConcurrentHashMap.

Yes, finally will be called after the execution of the try or catch code blocks.

The only times finally won't be called are:

1. If you invoke System.exit()
2. If you invoke Runtime.getRuntime().halt(exitStatus)
3. If the JVM crashes first
4. If the JVM reaches an infinite loop (or some other non-interruptable, non-terminating statement) in the try or catch block
5. If the OS forcibly terminates the JVM process; e.g., kill -9 <pid> on UNIX
6. If the host system dies; e.g., power failure, hardware error, OS panic, et cetera
7. If the finally block is going to be executed by a daemon thread and all other non-daemon threads exit before finally is called