An Introduction to Testing

Discussion

We must be able to access the current time so that we can create a suitable message for the sign. Recall from an earlier chapter, we introduced the standard class LocalTime, which is in the package java.time. If the statement:

LocalTime time = LocalTime.now(ZoneId.of("America/New_York"));

executes, the expression time() will return a string such as "16:19:38".

During talks with the franchise owner, we have designed the sign’s message. When Café Java is open for lunch, for example, its sign will display the following message:
  Café Java
  OPEN
  Serving Lunch until 2 p.m.
  The time now is 11:45
A few hours later, when the café is closed, the sign will display the following message:
  Café Java
  CLOSED
  See you at 5 p.m.
  The time now is 15:00

Since LocalTime uses a 24-hour notation for the time of day, we will use the same notation for now on the last line of our sign. To simplify our first solution even further, we can omit the third line, indicating the time that the café will reopen, from the message when the café is closed.

A trial program

Temporarily ignoring certain requirements in a problem statement by omitting features from our initial solutions is a wise plan. Writing one or more short programs to try out our ideas is another good strategy. So before we tackle our simplified problem statement, let’s write some code that gets the time of day and identifies the meal, if any, being served at that time. If you did Challenge 3 in the previous chapter, you’ve already given some thought to this identification task.

Here is some pseudocode that describes the steps we can take:

  Get a LocalTime object
  Extract the hour from the LocalTime object
  if (it is breakfast time)
    return “Breakfast”
  else if (it is lunchtime)
    return “Lunch”
  else if (it is dinnertime)
    return “Dinner”
  else
    return “Closed”

The program given below translates this pseudocode into the public method getMealServed. Run the program and check your results against the actual time of day.