I am trying to send File as a parameter to a method but dont know how?-CodePudding

public static void createFile() {

    File file = new File("C:\\Users\\egecoskun\\Desktop\\javafiles\\ananınamı.txt");
    try {
        if (file.createNewFile()) {
            System.out.println("Dosya olusturuldu!");

        } else {
            System.out.println("Dosya zaten var!");
        }
    } catch (IOException e) {
        e.printStackTrace();
    }

}

Here is my createFile method to create a file.

public static void readFile(File file) {
    try {
        Scanner reader = new Scanner(file);
        while(reader.hasNextLine()) {
            String line=reader.nextLine();
            System.out.println(line);
        }
    } catch (FileNotFoundException e) {

        e.printStackTrace();
    }

}

and this method is reading the file i am creating.But it needs to take File as an argument but when i try to run this method in Main

public static void main(String[] args) {
    createFile();
    readFile(file);

}

The error i am getting is file cannot be resolved to a variable. Does anyone spot my mistake? Can you explain it please.

CodePudding user response：

createFile is void; that means it does not return anything. In this case, you want to return a File. Like,

public static File createFile() {
    File file = new File("C:\\Users\\egecoskun\\Desktop\\javafiles\\ananınamı.txt");
    try {
        if (file.createNewFile()) {
            System.out.println("Dosya olusturuldu!");
            return file;
        } else {
            System.out.println("Dosya zaten var!");
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
    return null;
}

Then you need to assign the result of calling that method to a variable. And you should check that it is not null before you pass it to readFile. Like,

File f = createFile();
if (f != null) {
    readFile(f);
}

Note that the file won't actually contain anything to read. It just exists after you created it.

CodePudding user response：

Return file object from createFile Function and pass it to readFile Function

public static File createFile() {
    File dir = new File("C:\\Users\\egecoskun\\Desktop\\javafiles");
    if(dir.exists()) {
       dir.mkdirs();
    }
    File file = File(dir,"ananınamı.txt");
    file.createNewFile();
    return file;
}

In your main function

File file = createFile();
readFile(file);