Climbing the Ladder

This week we started the next phase of the DueDates project. We gained some experience with Continuous Integration using Hudson. Hudson gives us another level of oversight on our program, allowing us to double check our code. I found that it was a good way to catch errors that might not crop up during testing on a local system such as forgetting to upload a newly created java file. At one point Hudson was giving me errors about using @Override in certain portions of my code even though it passed verify on my system. Turns out that it noticed that those methods didn't actually override the superclass methods so @Override was unecessary.

Additionally we were tasked with adding new capabilities to our program, including supporting multiple libraries, sorting, and output control. To deal with the new arguments I added a bunch of conditional statements. To deal with the new requirements I first thought up of a complex program structure that involved storing book objects into a ArrayList for each library and storing each of those list into another ArrayList. Eventually my partner John Ly came up with a much simpler implementation that only needed a single ArrayList.

For the sorting method, at first my partner created a sorting method that used bubble sort. I decided that it was simpler to use the Collection class to sort the ArrayList and override the necessary methods. I spent some time fighting with FindBugs over EQ_COMPARETO_USE_OBJECT_EQUALS but eventually I resolved it. Additionally we first assumed that sorting by library didn't need any work since books were placed in the ArrayList by libraries according to the order of the arguments but eventually we realized that we didn't consider multiple account request to the same library. After some research I used the Comparator class in the Java API to add the library sort capability.

As for the within method we used a Calendar class help us contain the date information and used it also drop books from our ArrayList that weren't due within the user specified number of days.

For the project we met up twice for about 2 hours. During that time we shifted from my idea for the program structure to John Ly's idea for it. Having face to face helps quite a bit when you have to discuss complex program structures and features. It's a good way to ensure that the other person understands them. With other forms of communication it becomes a bit more diffucult. Eventually we finished meeting the requirements for the project. A distribution of the current state of the project can be found here.