Question

What to submit: your answers to exercises 2.

1. Write a Java program to perform the following tasks:

The program should ask the user for the name of an input file and the name of an output file. It should then open the input file as a text file (if the input file does not exist it should throw an exception) and read the contents line by line. It should also open the output file as a text file and write to it the lines in the input file, prefixed by line numbers starting at 1.

So if an input file named “fred.txt” contains:

Hello, I am Fred. I am enrolled in ICT167. Bye

and the user enters “fred.txt” and “fredNum.txt”, then after running the program “fredNum.txt” will contain something like:

1 Hello, 2 3 I am Fred. 4 I am enrolled in ICT167. 5 6 Bye

Finally, the program should display on the screen your name, the name of the output file, followed by a count of the total number of lines, the total number of words, and the total number of characters in the input file.

For the above input file, the following will be displayed to the screen:

My name = Joe Bloggs

Name of Output file = fredNum.txt Total number of lines in fred.txt = 6 Total number of words in fred.txt = 10

Total number of characters in fred.txt = 43

1. Write a Java program to perform the following tasks:

The program should ask the user for the name of an input file (scores.txt). The input file should contain 10 records. Each record in the input file should consist of a name and score between 0 and 100 (inclusive). Eg: fred 95

The program should open the input file as a text file (if the input file does not exist it should throw an exception) and read the contents line by line.

Store each record in an array of a user-defined Score class. The Score class can be kept very simple with 2 instance variables, a default constructor, get and set methods for the instance variables.

Now process the array of Score class objects to determine:

• The average of all scores
• The largest score
• The smallest score

Now output the above stats and all records to the file output.csv. The first line written to this file should consist of the number of records, the average score, the largest score and the smallest score; these values should be comma separated. Finally, the contents of the array of Score objects should be written to output.csv starting from the second line (the first line being taken by the above stats). The format to output the array contents is the same as the input file, with the exception that the fields should be comma separated instead of space separate

Answer 1

Code

First task

import java.io.File;
import java.io.FileWriter;
import java.util.Scanner;

public class Main {

public static void main(String[] args) {
int lineCount=0;
int wordCount=0;
int charCount=0;
String inputFile,outputFile;
Scanner input,scnr;
scnr=new Scanner(System.in);
System.out.println("Please enter input file name.");
inputFile=scnr.next();
System.out.println("Please enter output file name.");
outputFile=scnr.next();
  
try
{
input=new Scanner(new File(inputFile));
FileWriter myWriter = new FileWriter(outputFile);
String line;
while(input.hasNext())
{
lineCount++;
line=input.nextLine();
myWriter.write(lineCount+" "+line+"\n");
charCount+=line.length();
if(!line.isEmpty())
{
String words[]=line.split(" ");
wordCount+=words.length;
}
}
myWriter.close();
input.close();
System.out.println("My name = Joe Bloggs");
System.out.println("Name of Output file = "+outputFile+"\nTotal number of lines in "+inputFile+" = "+lineCount+"\nTotal number of words in fred.txt = "+wordCount);
System.out.println("Total number of characters in "+inputFile+" = "+charCount);
}
catch(Exception e)
{
System.out.println(inputFile+" file not found. Please try again.");
}
}
  
}

output

Output > Debugger Console Read file and the write to file with line number (run) x run: Please enter input file name. fred.txt Please enter output file name. fredNum.txt My name = Joe Bloggs Name of Output file = fredNum.txt Total number of lines in fred.txt = 6 Total number of words in fred.txt = 10 Total number of characters in fred.txt = 43 BUILD SUCCESSFUL (total time: 13 seconds) —

fredNum.txt file

- х fred Num - Notepad File Edit Format View Help Hello, 2 3 I am Fred. 4 I am enrolled in ICT167. 5 6 Bye Ln 1, Col 1 100% Unix (LF) UTF-8

Second task

Code

import java.io.File;
import java.io.FileWriter;
import java.util.Scanner;

class Score
{
private String name;
private int score;

public Score(String name, int score) {
this.name = name;
this.score = score;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public int getScore() {
return score;
}

public void setScore(int score) {
this.score = score;
}
  

}
public class ScoreTest {

public static void main(String[] args) {
String inputFile,name;;
int score,i=0,maxScore,minScore;
double sum=0,avg;
Score scoreArray[]=new Score[10];
final String outputFile="output.csv";
Scanner scnr,input;
scnr=new Scanner(System.in);
System.out.print("Enter input file name: ");
inputFile=scnr.next();
try
{
input=new Scanner(new File(inputFile));
while(input.hasNext())
{
name=input.next();
score=input.nextInt();
scoreArray[i]=new Score(name, score);
i++;
}
maxScore=minScore=scoreArray[0].getScore();
for(int j=0;j<i;j++)
{
sum+=scoreArray[j].getScore();

if(maxScore<scoreArray[j].getScore())
maxScore=scoreArray[j].getScore();

if(minScore>scoreArray[j].getScore())
minScore=scoreArray[j].getScore();
}
avg=sum/i;
FileWriter myWriter = new FileWriter(outputFile);
myWriter.write(i+","+avg+","+maxScore+","+minScore+"\n");
for(int j=0;j<i;j++)
myWriter.write(scoreArray[j].getName()+","+scoreArray[j].getScore()+"\n");
myWriter.close();
input.close();
}
catch(Exception e)
{
System.out.println(inputFile+" was not found. Please try again.");
}
}
  
}

scores.txt

- х scores - Notepad File Edit Format View Help Fred 96 Jack 85 Jill 78 Pintu 80 Bob 96 Alice 78 John 70 Abdul 90 Ali 85 Barak 80 Ln 1, Col 1 100% Windows (CRLF) UTF-8

output on console

Output > Debugger Console * Score class with read from file (run) x D Enter input file name: scores.txt BUILD SUCCESSFUL (total time: 4 seconds) run: |

output.csv

output.csv X 1 10,83.8,96,70 2 Fred, 96 3 Jack, 85 4 Jill,78 5 Pintu, 80 6 Bob,96 7 Alice, 78 8 John, 70 Abdul, 90 10 Ali, 85 11 Barak, 80 12 HHH

If you have any query regarding the code please ask me in the comment i am here for help you. Please do not direct thumbs down just ask if you have any query. And if you like my work then please appreciates with up vote. Thank You.