The whole world is a comedy
Read more about java.util.concurrent.locks.Lock at http://docs.oracle.com/ (Everything there is in Javadocs!) Write the implementation of the someMethod() method: 1. try to acquire the lock; 1.1. if the lock is busy, then call the actionIfLockIsBusy() method; 1.2. if the lock is free, then.
The world is boring for boring people
Analyze BlockingQueue. In the image and likeness of the Producer class, create a Consumer class that will output data from a BlockingQueue to the console.
The world doesn't change, we change
Analyze ConcurrentHashMap. In a separate file, create a Producer class that will: 1. every half second, add a key and value to a ConcurrentHashMap, where the key is the counter starting from 1, and the value is a phrase like "Some text for i", e.g. "Some text for 1".