There is a couple of good, general-purpose, third-party libraries available to Java developers, like Apache Commons and Google Guava. I always include these libraries in my projects, because they simplify a lot of tasks.

As Joshua Bloch rightly said in Effective Java, there is no point in re-inventing the wheels. We should prefer using tried and tested libraries instead of writing our own routines every now and then.

It’s good for Java developers to get themselves familiar with Google Guava and the Apache Commons library.