Simple Java programs

I have four university object oriented assignments I need to write a java program for. The assignments include 1.a) Write some simple java programs with hello world and reading numbers from the command prompt and conduct some arithmetic operations on them. 1.b) Position and coordinates and strings 2.a) Measurment and sensors, many classes that work together , sub-classes , and reading of the data from a webserver 3. Java graphic as well as standad classes for lists. Save list of positions as an arrays and iterators. A simple animation in the end of the assignment making a red circle that is made of the given positions. 4. The final assignment is to write a program that simulates how bunch of balls hit against the walls inside an isolated rectangular 2-D [login to view URL] the BreakOut game.