Java: print contents of text file to screen

Every example here shows a solution using the FileReader. It is convenient if you do not need to care about a file encoding. If you use some other languages than english, encoding is quite important. Imagine you have file with this text

Příliš žluťoučký kůň
úpěl ďábelské ódy

and the file uses windows-1250 format. If you use FileReader you will get this result:

P��li� �lu�ou�k� k��
�p�l ��belsk� �dy

So in this case you would need to specify encoding as Cp1250 (Windows Eastern European) but the FileReader doesn't allow you to do so. In this case you should use InputStreamReader on a FileInputStream.

Example:

String encoding = "Cp1250";
File file = new File("foo.txt");

if (file.exists()) {
    try (BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(file), encoding))) {
        String line = null;
        while ((line = br.readLine()) != null) {
            System.out.println(line);
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}
else {
    System.out.println("file doesn't exist");
}

In case you want to read the file character after character do not use BufferedReader.

try (InputStreamReader isr = new InputStreamReader(new FileInputStream(file), encoding)) {
    int data = isr.read();
    while (data != -1) {
        System.out.print((char) data);
        data = isr.read();
    }
} catch (IOException e) {
    e.printStackTrace();
}

Before Java 7:

 BufferedReader br = new BufferedReader(new FileReader("foo.txt"));
 String line;
 while ((line = br.readLine()) != null) {
   System.out.println(line);
 }

• add exception handling
• add closing the stream

Since Java 7, there is no need to close the stream, because it implements autocloseable

try (BufferedReader br = new BufferedReader(new FileReader("foo.txt"))) {
   String line;
   while ((line = br.readLine()) != null) {
       System.out.println(line);
   }
}

Why hasn't anyone thought it was worth mentioning Scanner?

Scanner input = new Scanner(new File("foo.txt"));

while (input.hasNextLine())
{
   System.out.println(input.nextLine());
}