- #1
smilesofmiles
- 18
- 0
Hello mathhelpboards community! I can't figure out how to get my code to execute while using buffered reader and try with resources. :-( I created a data.txt file correctly and it contains the numbers "0.5 3 10 70 90 80 20" without quotes. I added a catch IO Exception utilizing the printStackTrace function believing this would allow my program to run. I tried redoing the way I added the elements into my arrays thinking that I wasn't using buffered reader correctly. Frustration led me to google and youtube but I wasn't able to find buffered reader being used to add elements to an array. This was also my first time implementing FileWriter. I believe that portion is done correctly?
Any help, hints or points to the right direction will be greatly appreciated!
Any help, hints or points to the right direction will be greatly appreciated!
Code:
package calcweightedavgwithexceptions2;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;public class CalcWeightedAvgWithExceptions2 {
public static void main(String[] args) throws IOException {
ArrayList<Double> inputValues = getData();
double weightedAvg = calcWeightedAvg(inputValues);
printResults(inputValues, weightedAvg);
}
public static ArrayList<Double> getData() throws IOException {
File file = new File("data.txt"); //Hard code input file
ArrayList<Double> userNumbers = new ArrayList<Double>();
ArrayList<Double> userCopy = new ArrayList<>(userNumbers);
if(file.exists()){
try(BufferedReader buffy = new BufferedReader(new FileReader(file))) {
/*First attempt at fixing. I tried to redo how I used buffered reader to add elements to the array.*/
String strLine;
String values[] = null;
while ((strLine = buffy.readLine()) != null) {
values = strLine.split(" ");
}
for(int i = 0; i < values.length; i++){
userNumbers.add(Double.parseDouble(values[i]));
}
for (int j = 0; j < values.length; j++){
userCopy.add(Double.parseDouble(values[j]));
}
/* Second attempt. I kept thinking there must be something wrong with how I'm adding values to my arrays */
/*String in;
while ((in = buffy.readLine()) != null) {
userNumbers.add(Double.parseDouble(in));
}
while ((in = buffy.readLine()) != null) {
userCopy.add(Double.parseDouble(in));
}
buffy.close();
*/
}catch(FileNotFoundException fne){
String errorString = fne.getMessage();
System.out.println(errorString);
}catch(IOException e){ /*I added catch IO Exception but am not sure if I'm using it properly.*/
e.printStackTrace();
}
}
return userNumbers;
}
public static double calcWeightedAvg( final ArrayList<Double> userNumbers){
ArrayList<Double> userCopy = new ArrayList<>(userNumbers);
int n = (int) Double.parseDouble(userCopy.get(1).toString());
double sum = 0;
double weight = (double) userCopy.get(0);
userCopy.remove(0);
userCopy.remove(1);
Collections.sort(userCopy, Collections.reverseOrder());
for(int i = 0 ; i < userCopy.size() - n; i++){
sum = sum + Double.parseDouble(userCopy.get(i).toString()) * weight;
}
double avg = sum /(userCopy.size() - n);
return avg;
}
public static void printResults(ArrayList<Double> userNumbers, double weight) throws IOException{
int n = (int) Double.parseDouble(userNumbers.get(1).toString());
Scanner console = new Scanner(System.in);
System.out.print("Please name the output file: ");
String outputFileName = console.next();
System.out.println("Your output was placed in the file " + outputFileName);
try (FileWriter fw = new FileWriter(new File(outputFileName))){
fw.write("The weighted average of the numbers is " + weight + ", when using the data ");
for (int i = n; i < userNumbers.size(); i++) {
fw.write(userNumbers.get(i) + ", ");
}
fw.write("\nwhere " + userNumbers.get(0) + " is the weight used, ");
fw.write("and the average is computed after dropping the lowest " + n + " values.\n");
fw.flush();
fw.close();
}catch(FileNotFoundException fne){
String errorString = fne.getMessage();
System.out.println(errorString);
}catch(IOException e){
e.printStackTrace();
}
}
}