LAB #3: CLASSES

1. Task: Create a Time class. The class should contain 3 fields (integers called hrs, mins, secs, for hours, minutes and seconds) and the following methods:

  1. Default and alternate constructors.
  2. Three getters (accessors) to return hours, minutes and seconds
  3. A method named set; invalid values set to 0
  4. Two methods named printMilitary and printStandard to print each Time object in military and standard format
  5. A method toString()
  6. A method named equals to compare 2 Time objects for equality
  7. 2 methods named copy and getCopy  to make a copy of a Time object into another Time object
  8. A method named increment to advance time by 1 second
  9. A method named lessThan to decide if a time comes before another time

2. Task: Create a client for the Time class. Be very thorough with your testing (including invalid input) and have output similar to the sample output below:

 

Initial time t1 (alternate constructor invoked) - military format: 08:15:30
Initial time t1 (alternate constructor invoked) - standard format: 8:15:30 AM
Initial time t2 (default constructor invoked) - military format: 00:00:00
Initial time t2 (default constructor invoked) - standard format: 12:00:00 AM
t2 after call to setTime - military format: 09:45:35
t2 after call to setTime - standard format: 9:45:35 AM
After call to equals: times are NOT equal.
After call to lessThan: t1 is less than t2.
Enter hours, minutes, and seconds: 10 11 12
New time t1 after call to setTime - standard format: 10:11:12 AM
New time t1 after call to increment - standard format: 10:11:13 AM
New t2 after call to copy - standard format: 10:11:13 AM
Test toString for t2: 10:11:13

3. Task: Modify the Time class and add more methods.

 

3.1. The class Time (discussed in class) has 2 member methods equals and lessThan. It would be easier for the user to have access to new member methods notEquals, lessOrEquals, greaterThan, and greaterOrEquals. Hint: Don’t start from scratch; make use of the already existing methods.

public boolean notEquals(Time otherTime) {... }
public boolean lessOrEquals(Time otherTime) {... }
public boolean greaterThan(Time otherTime) {... }
public boolean greaterOrEquals(Time otherTime) {... }

3.2. Add 2 more methods named toMilitary and toStandard; they should return a String with the military and standard format for a Time object.

3.3. Have 3 methods to advance time, not only increment. Add to class Time the methods  advanceHrs, advanceMins, and advanceSecs.

3.4. Change the method getCopy() – try to have a single return statement

 

Modify the client for complete testing, including the new methods.

Notes:
A. The lab will NOT be graded, do NOT hand anything in to the instructor.
B. The lab should be completed by the start of the next scheduled lab class. Save the .java files on your disk and e-mail them (attachments) to Vishal Patel at vpatel12@students.towson.ed
Very important: Make sure that you have COSC 237.section, your name, and Lab#3 in the Subject box of your e-mail.
C. In case you have any problems, contact the instructor or the TA for assistance.