README.md

IO. Home Work 2

1. FileCopyUtil

Create 4 implementations of FileCopyUtil interface that implements copy method in the following way:

• Copy using byte-per-byte flow
• Copy using buffered streams
• Copy using Channels
• Copy using suitable methods from NIO

Generate demo file with size >= 1GB and perform performance testing of your implementations.

Create Demo class, that will print amount of time needed by each of implementation to copy demo file.

Be sure to handle possible exceptions properly.

Create jUnit tests for each of your implementation.

Performance testing

The easiest way to make some performance testing is to measure time used for execution of your functionality using timestamps "before" and "after" execution of your code:

public static void main(String[] args){
  long before = System.currentTimeMillis();
  // do some stuff
  long after = System.currentTimeMillis();
  System.out.println("Result:"+(after-before));
}

But such measurment won't be very accurate, due to possible JVM optimizations. To be sure that JVM have already perform all its bytecode optimizations and prepare more accurate result try to measure execution time of your code 1000-10000 times and calculate average execution time.

Additionally, add -server JVM option while executing your performance test.