FileReader won't read second file in a list

Question

I put two files in a directory and tested to see if my code can search through the files and find a match, but the FileReader won't read the second file. Here is my code and my console entry. I have narrowed the error down to the FileReader , but I don't know how to fix that.

public class Main 
{
  public static void searchEngine(String dir, String Search) 
  {
    File folder = new File(dir);
    String[] files = folder.list();
    Integer f1 = 0;
    FileReader fileReader;
    ArrayList linematches;
    BufferedReader bufferedReader;
    Integer q;
    String line;
    Integer linenum;

    System.out.println("Found Files:");
    for (String file : files) {
        System.out.println(file);
    }
    try {
        for (String file : files) {
            linematches = new ArrayList();
            fileReader = new FileReader(files[f1]);
            bufferedReader = new BufferedReader(fileReader);
            linenum = 0;
            while ((line = bufferedReader.readLine()) != null) {
                linenum += 1;
                if (line.contains(Search)) {
                    linematches.add(linenum);
                }
            }
            q = 0;
            for (int i = 0; i < linematches.size(); i++) {
                System.out.println("File: " + file + "  Line: " + linematches.get(i));
            }
            linematches.removeAll(linematches);
            // Always close files.
            bufferedReader.close();
            f1++;
        }
    } catch (FileNotFoundException ex) {
        System.out.println("Unable to open file '" + dir + "'");
    } catch (IOException ex) {
        System.out.println("Error reading file '" + dir + "'");
    }
  }

  public static void main(String[] args) 
  {
    while (true) {
        System.out.println("Enter the search term: ");
        Scanner scanner = new Scanner(System.in);
        String searchterm = scanner.nextLine();
        System.out.println("Enter each file location: ");
        String f1 = scanner.nextLine();
        searchEngine(f1, searchterm);
    }
  }
}

Here is the output of my console:

Enter the search term: 
bla
Enter each file location: 
test dir
Found Files:
testfile.txt
testfile2.txt
Unable to open file 'test dir'

The entire stack trace of the error is:

Unable to open file 'testfile2.txt' java.io.FileNotFoundException:
testfile2.txt (No such file or directory) Enter the search term: at
java.io.FileInputStream.open0(Native Method) at
java.io.FileInputStream.open(FileInputStream.java:195) at
java.io.FileInputStream.(FileInputStream.java:138) at
java.io.FileInputStream.(FileInputStream.java:93) at
java.io.FileReader.(FileReader.java:58) at
com.mangodev.Main.searchEngine(Main.java:32) at
com.mangodev.Main.main(Main.java:70)

Please help. Thank you.

Answer 1

It looks to me as if you have the following folder structure:

Main.class
Main.java
test dir
|-- testfile.txt
|-- testfile2.txt

You run the code from the directory containing Main.class , Main.java and test dir . Your code then lists files in the directory test dir , finding the two text files it contains, but then attempts to open them from the current directory . This is the parent directory, and of course, this isn't where those files are. They are in the sub-directory test dir . A FileNotFoundException is therefore to be expected: you're attempting to open a file in the wrong directory.

If the FileReader happens to fail on the second of the two files, does there happen to be a file testfile.txt in the parent directory as well? Your code may well have been opening this file first time through the loop instead of the one in test dir that you thought it was.

To open files within the test dir subdirectory, replace the line

        fileReader = new FileReader(files[f1]);

with

        fileReader = new FileReader(new File(dir, files[f1]));

Answer 2

In your first line in the searchEngine method you create a variable folder that contains the files in the directory. I suggest using this variable directly in your for loop instead of string filenames.

for (File file : folder.listFiles()) {
    linematches = new ArrayList();
    fileReader = new FileReader(file);
    bufferedReader = new BufferedReader(fileReader);
    //rest of code...
}