Question

Program: Java

Write a Java program using good programming principles that will aggregate the values from several input files to calculate relevant percentages and write the values to an output file.

You have been tasked with reading in values from multiple files that contains different pieces of information by semester.    The Department of Education (DOE) would like the aggregate values of performance and demographic information by academic year. A school year begins at the fall semester and concludes at the end of the summer semester the following year. Fall 2019 - Summer 2020 is considered one academic year.

Input Files

• Input files named Fall2019Analytics.txt, Spring2020Analytics.txt, and Summer2020Analytics.txt have been placed in Canvas.   Each have the same layout but differ by semesters.
• Each file contains several pieces of data by program - total enrollment, enrollment by gender, completion by gender, enrollment by ethnicity, completion by ethnicity, among other pieces of data.  
• The program should read in the values from these input files, aggregate the data, and write the information to an output file that will be sent to Tallahassee.
• From there, the DOE will use this output file as input to aggregate the data from other schools within the state of Florida.
• It is important that this file is formatted in the proper sequence that the DOE needs - otherwise the college will be heavily fined and may lose accreditation.

These input files contain the data for three programs on campus:

Program code 3624
Program code 5651
Program code 6635

Input file layout (all integer values) by semester:

• program number
• total number of students enrolled in the program
• total number of student completers in the program
• total number of female students enrolled in the program
• total number of male students enrolled in the program
• total number of unknown/not reported gender students enrolled in the program
• total number of female student completers in the program
• total number of male student completers in the program
• total number of unknown/not reported student completers in the program
• total number of Asian students enrolled in the program
• total number of Black students enrolled in the program
• total number of Hispanic students enrolled in the program
• total number of Multiracial students enrolled in the program
• total number of Native American students enrolled in the program
• total number of Native Hawaiian students enrolled in the program
• total number of Unknown/not reported ethnicity students enrolled in the program
• total number of White students enrolled in the program
• total number of Asian student completers in the program
• total number of Black student completers in the program
• total number of Hispanic student completers in the program
• total number of Multiracial student completers in the program
• total number of Native American student completers in the program
• total number of Native Hawaiian student completers in the program
• total number of Unknown ethnicity student completers in the program
• total number of White students completer in the program

Notes

• Each value within the file for a program is separated by one space.
• Each program code is on its own line in each file. There are three lines per file.
• Use an array or arrayList to hold the values within each file.
• Each semester should be coded within their own class.

Calculations

The following values must be calculated:

For each semester:
   - the percentage of students completers (total number of student completers / total number of students enrolled)

For each individual program code:
   - grand totals for each category (enrolled, completers, gender, and ethnicity)

Aggregate for all semesters:

   - the total number of students enrolled
   - the total number of student completers
   - the total number by gender
   - the total number by each ethnicity
   - the percentage of student completers (total completers / total enrolled)
   - the percentage of female completers (total number of female completers / total number of female enrolled)
   - the percentage of male completers
   - the percentage of each ethnicity

Output

The output for this project will be two-fold.   The output will be displayed in a Message dialog box and an output file.

The Message Dialog boxes:

Each percentage calculated should be displayed in percentage format with one decimal place.

A sample format (the values are not accurate, this is only for formatting purposes):

Santa Fe College Academic Year 2019 - 2020 Program codes: 3624, 5651, and 6635 Aggregate total number of student enrolled:       5555 Aggregate total number of student completers: 4444 Aggregate percentage of students completing for the academic year: 81.2% Percentage of students completing Fall 2019:             76.9% Percentage of students completing Spring 2020:        85.3% Percentage of students completing Summer 2020:     84.1%

On the next dialog screen, display the following:

Santa Fe College Academic Year 2019 - 2020 Program codes: 3624, 5651, and 6635 Aggregate values for: Female student completers:     88.8% Male student completers:                        88.7% Unknown/not reported completers:    89.1% Asian completers:    90.1% Black completers:                                        90.2% Hispanic completers:                                 90.3% Multiracial completers:                             90.4% Native American completers:      90.5% Native Hawaiian completers:                  90.6% Unknown/Not Reported completers:   90.7% White completers:                                       90.8%

Output File

The output file should be named Analytics2019.txt and should be written to:   C\SFC\COP2552\Project4

The layout of the output file is:

academic year (2019)
aggregate total of students enrolled
aggregate total of student completers
aggregate total number of female students enrolled
aggregate total number of female student completers
aggregate total number of male students enrolled
aggregate total number of male student completers
aggregate total number of unreported/unknown students enrolled
aggregate total number of unreported/unknown student completers
aggregate total number of Asian students enrolled
aggregate total number of Black students enrolled
aggregate total number of Hispanic students enrolled
aggregate total number of Multiracial students enrolled
aggregate total number of Native American students enrolled
aggregate total number of Native Hawaiian students enrolled
aggregate total number of Unknown/Not Reported students enrolled
aggregate total number of White students enrolled
aggregate total number of Asian student completers
aggregate total number of Black students completers
aggregate total number of Hispanic students completers
aggregate total number of Multiracial students completers
aggregate total number of Native American students completers
aggregate total number of Native Hawaiian students completers
aggregate total number of Unknown/Not Reported students completers
aggregate total number of White students completers
program number (3624)
total number of students enrolled in the program
total number of student completers in the program
total number of female students enrolled in the program
total number of male students enrolled in the program
total number of unknown/not reported gender students enrolled in the program
total number of female student completers in the program
total number of male student completers in the program
total number of unknown/not reported student completers in the program
total number of Asian students enrolled in the program
total number of Black students enrolled in the program
total number of Hispanic students enrolled in the program
total number of Multiracial students enrolled in the program
total number of Native American students enrolled in the program
total number of Native Hawaiian students enrolled in the program
total number of Unknown/not reported ethnicity students enrolled in the program
total number of White students enrolled in the program
total number of Asian student completers in the program
total number of Black student completers in the program
total number of Hispanic student completers in the program
total number of Multiracial student completers in the program
total number of Native American student completers in the program
total number of Native Hawaiian student completers in the program
total number of Unknown ethnicity student completers in the program
total number of White student completers in the program
program number (5651)
total number of students enrolled in the program
total number of student completers in the program
total number of female students enrolled in the program
total number of male students enrolled in the program
total number of unknown/not reported gender students enrolled in the program
total number of female student completers in the program
total number of male student completers in the program
total number of unknown/not reported student completers in the program
total number of Asian students enrolled in the program
total number of Black students enrolled in the program
total number of Hispanic students enrolled in the program
total number of Multiracial students enrolled in the program
total number of Native American students enrolled in the program
total number of Native Hawaiian students enrolled in the program
total number of Unknown/not reported ethnicity students enrolled in the program
total number of White students enrolled in the program
total number of Asian student completers in the program
total number of Black student completers in the program
total number of Hispanic student completers in the program
total number of Multiracial student completers in the program
total number of Native American student completers in the program
total number of Native Hawaiian student completers in the program
total number of Unknown ethnicity student completers in the program
total number of White student completers in the program
program number (6635)
total number of students enrolled in the program
total number of student completers in the program
total number of female students enrolled in the program
total number of male students enrolled in the program
total number of unknown/not reported gender students enrolled in the program
total number of female student completers in the program
total number of male student completers in the program
total number of unknown/not reported student completers in the program
total number of Asian students enrolled in the program
total number of Black students enrolled in the program
total number of Hispanic students enrolled in the program
total number of Multiracial students enrolled in the program
total number of Native American students enrolled in the program
total number of Native Hawaiian students enrolled in the program
total number of Unknown/not reported ethnicity students enrolled in the program
total number of White students enrolled in the program
total number of Asian student completers in the program
total number of Black student completers in the program
total number of Hispanic student completers in the program
total number of Multiracial student completers in the program
total number of Native American student completers in the program
total number of Native Hawaiian student completers in the program
total number of Unknown ethnicity student completers in the program
total number of White students completers in the program

(Use any numbers for .TXT)

Answer 1

Computer Files

A computer file is used to store data in digital format like plain text, image data, or any other content. Computer files can be organized inside different directories. Files are used to keep digital data, whereas directories are used to keep files.

Computer files can be considered as the digital counterpart of paper documents. While programming, you keep your source code in text files with different extensions, for example, C programming files end with the extension .c, Java programming files with .java, and Python files with .py.

File Input/Output

Usually, you create files using text editors such as notepad, MS Word, MS Excel or MS Powerpoint, etc. However, many times, we need to create files using computer programs as well. We can modify an existing file using a computer program.

File input means data that is written into a file and file output means data that is read from a file. Actually, input and output terms are more related to screen input and output. When we display a result on the screen, it is called output. Similarly, if we provide some input to our program from the command prompt, then it is called input.

For now, it is enough to remember that writing into a file is file input and reading something from a file is file output.

File Operation Modes

Before we start working with any file using a computer program, either we need to create a new file if it does not exist or open an already existing file. In either case, we can open a file in the following modes −

• Read-Only Mode − If you are going to just read an existing file and you do not want to write any further content in the file, then you will open the file in read-only mode. Almost all the programming languages provide syntax to open files in read-only mode.

• Write-Only Mode − If you are going to write into either an existing file or a newly created file but you do not want to read any written content from that file, then you will open the file in write-only mode. All the programming languages provide syntax to open files in write-only mode.

• Read & Write Mode − If you are going to read as well as write into the same file, then you will open file in read & write mode.

• Append Mode − When you open a file for writing, it allows you to start writing from the beginning of the file; however it will overwrite existing content, if any. Suppose we don’t want to overwrite any existing content, then we open the file in append mode. Append mode is ultimately a write mode, which allows content to be appended at the end of the file. Almost all the programming languages provide syntax to open files in append mode.

In the following sections, we will learn how to open a fresh new file, how to write into it, and later, how to read and append more content into the same file.

Opening Files

You can use the fopen() function to create a new file or to open an existing file. This call will initialize an object of the type FILE, which contains all the information necessary to control the stream. Here is the prototype, i.e., signature of this function call −

FILE *fopen( const char * filename, const char * mode );

Here, filename is string literal, which you will use to name your file and access mode can have one of the following values −

Sr.No	Mode & Description
1	r Opens an existing text file for reading purpose.
2	w Opens a text file for writing. If it does not exist, then a new file is created. Here, your program will start writing content from the beginning of the file.
3	a Opens a text file for writing in appending mode. If it does not exist, then a new file is created. Here, your program will start appending content in the existing file content.
4	r+ Opens a text file for reading and writing both.
5	w+ Opens a text file for both reading and writing. It first truncates the file to zero length, if it exists; otherwise creates the file if it does not exist.
6	a+ Opens a text file for both reading and writing. It creates a file, if it does not exist. The reading will start from the beginning, but writing can only be appended.

Closing a File

To close a file, use the fclose( ) function. The prototype of this function is −

 int fclose( FILE *fp );

The fclose( ) function returns zero on success, or EOF, special character, if there is an error in closing the file. This function actually flushes any data still pending in the buffer to the file, closes the file, and releases any memory used for the file. The EOF is a constant defined in the header file stdio.h.

There are various functions provided by C standard library to read and write a file character by character or in the form of a fixed length string. Let us see a few of them in the next section.

Writing a File

Given below is the simplest function to write individual characters to a stream −

int fputc( int c, FILE *fp );

The function fputc() writes the character value of the argument c to the output stream referenced by fp. It returns the written character written on success, otherwise EOF if there is an error. You can use the following functions to write a null-terminated string to a stream −

int fputs( const char *s, FILE *fp );

The function fputs() writes the string s into the file referenced by fp. It returns a non-negative value on success, otherwise EOF is returned in case of any error. You can also use the function int fprintf(FILE *fp,const char *format, ...) to write a string into a file. Try the following example −

#include <stdio.h>

int main() {
   FILE *fp;

   fp = fopen("/tmp/test.txt", "w+");
   fprintf(fp, "This is testing for fprintf...\n");
   fputs("This is testing for fputs...\n", fp);
   fclose(fp);
}

When the above code is compiled and executed, it creates a new file test.txt in /tmp directory and writes two lines using two different functions. Let us read this file in the next section.

Reading a File

Given below is the simplest function to read a text file character by character −

int fgetc( FILE * fp );

The fgetc() function reads a character from the input file referenced by fp. The return value is the character read; or in case of any error, it returns EOF. The following function allows you to read a string from a stream −

char *fgets( char *buf, int n, FILE *fp );

The function fgets() reads up to n - 1 characters from the input stream referenced by fp. It copies the read string into the buffer buf, appending a null character to terminate the string.

If this function encounters a newline character '\n' or EOF before they have read the maximum number of characters, then it returns only the characters read up to that point including the new line character. You can also use int fscanf(FILE *fp, const char *format, ...) to read strings from a file, but it stops reading after encountering the first space character.

#include <stdio.h>

main() {

   FILE *fp;
   char buff[255];

   fp = fopen("/tmp/test.txt", "r");
   fscanf(fp, "%s", buff);
   printf("1 : %s\n", buff );

   fgets(buff, 255, (FILE*)fp);
   printf("2: %s\n", buff );
   
   fgets(buff, 255, (FILE*)fp);
   printf("3: %s\n", buff );
   fclose(fp);
}

When the above code is compiled and executed, it reads the file created in the previous section and produces the following result −

1 : This
2 : is testing for fprintf...

3 : This is testing for fputs...

Let's analyze what happened here. First, the fscanf() method reads This because after that, it encountered a space. The second call is for fgets(), which reads the remaining line till it encountered end of line. Finally, the last call fgets() reads the second line completely.

File I/O in Java

Java provides even richer set of functions to handle File I/O. For more on this topic, we suggest you to check our Java Tutorials.

Here, we will see a simple Java program, which is equivalent to the C program explained above. This program will open a text file, write a few text lines into it, and close the file. Finally, the same file is opened and then read from an already created file. You can try to execute the following program to see the output −

import java.io.*;

public class DemoJava {
   public static void main(String []args) throws IOException {
      File file = new File("/tmp/java.txt");
      
      // Create a File
      file.createNewFile();
      
      //  Creates a FileWriter Object using file object
      FileWriter writer = new FileWriter(file); 
      
      // Writes the content to the file
      writer.write("This is testing for Java write...\n");
      writer.write("This is second line...\n");
      
      // Flush the memory and close the file
      writer.flush();
      writer.close();
      
      // Creates a FileReader Object
      FileReader reader = new FileReader(file); 
      char [] a = new char[100];
      
      // Read file content in the array
      reader.read(a);
      System.out.println( a );
      
      // Close the file
      reader.close();
   }
}

When the above program is executed, it produces the following result −

This is testing for Java write...
This is second line...

File I/O in Python

The following program shows the same functionality to open a new file, write some content into it, and finally, read the same file −

# Create a new file
fo = open("/tmp/python.txt", "w")

# Writes the content to the file
fo.write( "This is testing for Python write...\n");
fo.write( "This is second line...\n");

# Close the file
fo.close()

# Open existing file
fo = open("/tmp/python.txt", "r")

# Read file content in a variable
str = fo.read(100);
print str

# Close opened file
fo.close()

When the above code is executed, it produces the following result −

This is testing for Python write...
This is second line...