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CSE142 Program Example handout #22
Input file section.txt
----------------------
1 1 1 1 1 1 1 1 1
1 1 1 0 1 1 1 0 1
1 0 1 1 1 1 1 1 1
0 1 1 1 1 0 1 1 1
1 1 0 1 1 0 1 0 0
1 1 1 0 0 1 0 0 1
1 0 1 0 1 0 0 1 1
1 0 1 0 1 0 1 0 1
Output file section.out
-----------------------
3 3 3 3 3 3 2 0 0
3 3 3 0 3 3 3 0 2
3 0 3 3 3 3 3 2 0
0 3 3 3 3 0 3 3 2
3 3 0 3 3 0 3 0 0
3 3 3 0 0 3 0 0 3
3 0 3 0 3 0 0 3 3
3 0 3 0 3 0 3 0 3
Log of execution
----------------
This program processes an input file of
section attendance scores.
What is the name of the input file? section.txt
What is the name of the output file? section.out
3 3 3 3 3 3 2 0 0
3 3 3 0 3 3 3 0 2
3 0 3 3 3 3 3 2 0
0 3 3 3 3 0 3 3 2
3 3 0 3 3 0 3 0 0
3 3 3 0 0 3 0 0 3
3 0 3 0 3 0 0 3 3
3 0 3 0 3 0 3 0 3
Program file Section.java
-------------------------
// Stuart Reges
// 11/15/04
//
// This program converts an input file of section attendance scores from a
// boolean (0/1) form to a numerical form. A 0 means someone did not attend,
// a 1 means they did attend. Students get 3 points for each section they
// attend with a maximum of 20 points. The input file consists of input lines
// each of which have one student's attendance record in the 0/1 form. The
// output file lists the corresponding points for attendance. The output is
// also echoed to System.out.
import java.io.*;
public class Section {
public static final int SECTIONS = 9; // # of section scores per line
public static void main(String[] args) {
System.out.println("This program processes an input file of");
System.out.println("section attendance scores.");
System.out.println();
Scanner console = new Scanner(System.in);
Scanner input = getInput(console);
PrintStream output = getOutput(console);
processFile(input, output);
output.close();
}
// prompts the user for a file name and reads the result using the
// console Scanner until the user gives a legal file name
public static Scanner getInput(Scanner console) {
Scanner result = null;
while (result == null) {
System.out.print("What is the name of the input file? ");
String name = console.nextLine();
try {
result = new Scanner(new File(name));
} catch (FileNotFoundException e) {
System.out.println("File not found. Please try again.");
}
}
System.out.println();
return result;
}
// prompts the user for an output file name and reads the result using the
// console Scanner until the user gives a legal file name
public static PrintStream getOutput(Scanner console) {
PrintStream result = null;
while (result == null) {
System.out.print("What is the name of the output file? ");
String name = console.nextLine();
try {
result = new PrintStream(new FileOutputStream(name));
} catch (FileNotFoundException e) {
System.out.println("Can't open that file. Please try again.");
}
}
System.out.println();
return result;
}
// processes an entire input file line by line
public static void processFile(Scanner input, PrintStream output) {
while (input.hasNextLine()) {
String text = input.nextLine();
Scanner data = new Scanner(text);
int[] scores = new int[SECTIONS];
fillIn(scores, data);
report(output, scores);
report(System.out, scores);
}
}
// fills in the scores for a series of boolean (0/1) section scores
// stored in the given scanner, making sure that no student goes over
// 20 points
public static void fillIn(int[] scores, Scanner data) {
int sum = 0;
for (int i = 0; i < SECTIONS; i++) {
int next = data.nextInt();
if (next == 1 && sum < 18)
scores[i] = 3;
else if (next == 1 && sum == 18)
scores[i] = 2;
else
scores[i] = 0;
sum += scores[i];
}
}
// reports a set of scores on a single line of output to the given
// print stream
public static void report(PrintStream output, int[] scores) {
for (int i = 0; i < SECTIONS; i++)
output.print(scores[i] + " ");
output.println();
}
}
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