CS

ELI CSC 201

Unit 8 Programming Problems Worksheet

Programming Problem 1 – Fraction

Consider the following class:

public  class Fraction{                 private int numerator;                 private int denominator;                 private static char slash = ‘/’,  }

Write a program to instantiate an object of the Fraction class to test the class..  Add a constructor(s), set and get methods to the Fraction class appropriately.  Using the Serializable Interface, instantiate and write three Fraction objects to a file called “SerialF.dat.”  A loop must be used when creating and writing the three objects to the file. You can select the values you wish to use for the denominator and numerator. 

Directions

· Create the Fraction Class.

· Add a constructor(s), set and get methods to the Fraction class appropriately.

· Ensure the class is Serializable.

· Use a loop to create three Fraction objects.

· Initialize the three objects,

· Write each object to the file“SerialF.dat.”

· Display an appropriate message if an exception occurs.

Grading Rubric

Task	Points
Fraction class implements Serializable	0.5
The main method throws an IOException	1
The file "SerialF.dat" is created properly	1
Loop used to instantiate objects	1
Objects are correctly written to file "SerialF.dat"	1
The file "SerialF.dat" is closed appropriately	0.5
Proper documentation	1
Program works effectively	1
Total	7

Screenshots

Programming Problem 2 – ReadMe

The pledge of Allegiance states, “I pledge allegiance to the Flag of the United States of America, and to the Republic for which it stands: one Nation under God, indivisible, With Liberty and Justice for all.” Save the pledge, 174 characters, to a text file.  Use the RandomAccessFile class to access the file.  Using Seek method, display the characters at positions 124 and 135 only. 

Directions

· Create a text file with the pledge of allegiance named Pledge.txt using notepad.

· Create a reference to the file, Pledge.txt, using the RandomAccessFile class.

· Use the Seek method to point at positions 124 and 135, then display the characters represented by the byte streams.

· Use try, catch and finally blocks for exception handling.

Grading Rubric

Task	Points
Throws clause added in main method of the ReadMe class	1
Create a reference of the RandomAccessFile class which points to Pledge.txt	1
Include try, catch and finally blocks for exception handling	1
Use the Seek method to point at positions 124 and 135, then display characters represented by the byte streams	1
Proper documentation	1
Program works effectively	1
Total	6

Screenshots

Programming Problem 3 – ReadWrite

Write an application which will write five student ID numbers and GPAs to a “rw” file called “Stu.dat” and then allow you to display the GPA of any student upon entering their ID number, for any number of students.

Directions

· Import the classes necessary to support your application.

· Create a class called ReadWrite.  This class has no properties or behaviors.

· Create a main method which will include the following:

· Add an appropriate throws statement in the main method.

· Create a reference to a text file called “Stu.dat” with “rw” access.

· Include try and catch blocks for exception handling.

· Use a loop to interactively assign student ID numbers and their GPA scores.

· With the use of a second loop, display the GPA for specific student ID numbers.

· Use a sentinel to determine when you wish to stop the program.

· Include a finally block within your program.

Note: User defined methods are not required but may be used if you prefer.

Grading Rubric

Task	Points
Throws clause added in main method	0.25
Create a reference to the RandomAccessFile class	1
Include try and catch blocks for exception handling	1
Use a loop to interactively assign student ID numbers and their GPA scores	1
Use of a second loop to display the GPA for specific student ID numbers	1
Use of a sentinel to determine when you wish to stop the program	0.25
Include a finally block within your program	0.5
Proper documentation	1
Program works effectively	1
Total	7

Screenshots

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