Labs

In these labs we will use the interfaces and sorting methods from this chapter to sort data.

Starter code: CollectionSorting/com.example.sorting.labs.

Solutions: com.example.sorting.solutions.labs

  1. The PlanetSorter class loads and prints a list of Planet objects. Create a Comparator that will sort planets in reverse order of orbit. Use Collections.sort and the Comparator to sort the list before printing it.

(Solution: PlanetReverseOrbitComparator.java, PlanetSorter.java)

  1. Change PlanetSorter to have the list sort itself instead of using Collections.sort.

(Solution: PlanetSorter2.java)

  1. The access_log file contains records of hits to a web site. Consider each line equivalent to one hit, and the first space-separated word on each line identifies the visitor. Write a Java application that reads this file a line at a time, and counts the number of hits from each unique visitor, storing the results in a Map.

When all the records have been read, display the unique visitors along with the corresponding number of total hits. (Hint: Use String's split() method to get the first field of each line.)

(Solution: ShowHits.java)

  1. (Optional) Modify your solution to sort the displayed records according to the total number of hits for each visitor.

(Solution: ShowSortedHits.java)

Prev -- Up