CODEWITHSUNDEEP
java
anthino12
anthino12

Reputation: 958

Reading twice an InputStream throws IOException

I'm facing a problem, can someone tell me how to void this? It throws up an "java.io.IOException: Stream closed". I know where my mistake is but I dont know how to fix it. BufferedReader closes from the first function and I dont know how to reset it within the second one. Function should format text from one text file to another with tabs. Thank you 

import java.io.*;

public class TestClass {

private void prosekStudentKRS(FileReader fr) throws IOException{
    BufferedReader reader = null;

    int j = 0, vksum = 0;
    try{
        reader = new BufferedReader(fr);
        reader.readLine();
        String line;
        while((line = reader.readLine()) != null) {

            int sum = 0;
            j++;
            String[] niza = line.split(",");
            for(int i = 1; i < niza.length; i ++) {
                sum+=Integer.parseInt(niza[i]);
            }
            vksum += Integer.parseInt(niza[1]);
            System.out.printf("Student %d ima prosek %.2f\n", j, (float) sum / 3);
        }


        System.out.println("Prosek po KRS: " + vksum / (double) j);
    } catch (Exception e){
        e.printStackTrace();
    } finally {
        if(reader != null) {
            reader.close();
        }
    }

}

private void TSV(FileReader fr, FileWriter fw) throws IOException {

    BufferedReader reader = null;
    BufferedWriter writer = null;
    StringBuilder sb = null;
    try {
        reader = new BufferedReader(fr);
        writer = new BufferedWriter(fw);

        String line;
        while ((line = reader.readLine()) != null) {
            String[] niza = line.split(",");
            sb = new StringBuilder();
            for(int i = 0; i < niza.length; i ++) {
                sb.append(niza[i] + "\t");
            }
            writer.write(sb.toString());
            writer.newLine();
            writer.flush();
        }


    } finally {
        if (reader != null)
            reader.close();

        if(writer != null) {
            writer.flush();
            writer.close();
        }
    }
}


public static void main(String[] args) throws IOException{

    FileReader fr = new FileReader("C:\\Users\\pc\\IdeaProjects\\LabOS01\\rezultaticsv.txt");
    FileWriter fw = new FileWriter("C:\\Users\\pc\\IdeaProjects\\LabOS01\\rezultatitsv.txt");
    TestClass filetest = new TestClass();

    filetest.prosekStudentKRS(fr);
    filetest.TSV(fr, fw);
    }
}

Upvotes: 1

Views: 149

Answers (1)

davidxxx
davidxxx

Reputation: 131326

Either create two distinct FileReader objects and pass a different to each method.
Otherwise you can also create a BufferedReader from the FileReader before invoking the methods, pass it to the first method, reset it with the reset() method and pass it to the other method.

As alternative if the file is not too big, you could store in a List<String> each line read rather than reading again the file.
It would be more efficient.

Upvotes: 1

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