if you want to run these class the follow the steps (you should me familier with the java IDE like intellij , eclips etc.)

1. create a project
2. create a package named "Sorting"
3. create 4 java Class with name "Main.java" "MergeSort.java" "QuickSort.java" "HeapSort.java"
4. copy the code from the corresponding classes
5. run by Main.java Class :)