Answers
Question 1: Assume that you have written some classes. Belatedly, you
decide that they should be split into three packages, as
listed in the table below. Furthermore, assume that the
classes are currently in the default package (they have
no
package statements).
|
Package Name |
Class Name |
|
mygame.server
|
Server
|
|
mygame.shared
|
Utilities
|
|
mygame.client
|
Client
|
a. What line of code will you need to add to each source
file to put each class in the right package?
Answer 1a: The first line of each file
must specify the package:
- In
Client.java add:
-
package mygame.client;
- In
Server.java add:
-
package mygame.server;:
- In
Utilities.java add:
-
package mygame.shared;
b. To adhere to the directory structure, you will need to
create some subdirectories in your development directory,
and put source files in the correct subdirectories. What
subdirectories must you create? Which subdirectory does
each source file go in?
Answer 1b: Within the
mygame
directory, you need to create three subdirectories:
client,
server, and
shared.
- In
mygame/client/ place:
-
Client.java
- In
mygame/server/ place:
-
Server.java
- In
mygame/shared/ place:
-
Utilities.java
c. Do you think you'll need to make any other changes to
the source files to make them compile correctly?
If so, what?
Answer 1c: Yes, you need to add import statements.
Client.java and
Server.java need to import the
Utilities class, which they can do in one of two ways:
import mygame.shared.*;
--or--
import mygame.shared.Utilities;
Also,
Server.java needs to import the
Client class:
import mygame.client.Client;
Exercises
Exercise 1: Download three source files:
a. Implement the changes you proposed in question 1,
using the source files you just downloaded.
b. Compile the revised source files. (
Hint:
If you're invoking the compiler from the command line
(as opposed to using a builder), invoke the compiler from
the directory that contains the
mygame directory
you just created.)
Answer 1: Download this zip file with the solution:
mygame.zip
You might need to change your proposed import code to reflect our implementation.
