Class 15: Laboratory: Java Basics, Continued

Held: Tuesday, 21 September 2004

Summary: Today we continue check our understanding of Java basics by writing some more simple Java programs.

Related Pages:

• EBoard.

Assignments

• Finish both labs.

Notes:

• There were apparantly lots of problems on the lab, so we'll discuss your problems today.

Preparation

All of today's work should be in package userid.lab02. Please create and share the appropriate directories.

Exercise 1: A Date Interface

Write a Java interface called Date that describes the following methods:

• String toString()
• int getYear()
• int getMonth()
• String getMonthAsString()
• int getDayOfMonth()
• int getDayOfYear()
• Date tomorrow()
• Date yesterday()

Exercise 2: A Date Implementation

a. Write a Java model class called DateV1 that implements the Date interface. This class should have three fields: year, month, and dayofmonth. You do not need to worry about leap years.

b. Write a Java main class called TestDateV1 that creates a DateV1 with today's date and pritns the result of each of the methods in the class.

Exercise 3: Another Date Implementation

a. Write a Java mold class called DateV2 that implements the Date interface. This class should have only two fields: year and dayofyear.

b. Write a Java main class called TestDateV2 that creates a DateV2 with today's date and pritns the result of each of the methods in the class.