CODEWITHSUNDEEP
javabufferedreaderfilereader
Shawn R.
Shawn R.

Reputation: 161

Java, FileReader() only seems to be reading the first line of text document?

I'm still in the process of learning so please correct me if I'm misunderstanding, but shouldn't the FileReader object return the entire contents of a text file?

I have a snippet of code here where I'm simple trying to take the contents of a short .txt file, and print it using system.out.println() 

public class Main {

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

    File testDoc = new File("C:\\Users\\Te\\Documents\\TestDocument.txt");
    BufferedReader reader = new BufferedReader(new FileReader(testDoc));
    Scanner in = new Scanner(new FileReader(testDoc));


    try {
      System.out.println(reader.readLine());
    } finally {
      reader.close();
    }
  }
}

The .txt file contains only 3 lines, formatted like so:

some text here, more text and stuff
new estonian lessons
word = new word

However the program is only printing the first line in the file.

some text here, more text and stuff

What is causing this, and how do I correct it?

I've tried reading the documentation, as well as searching through Stackoverflow, but I haven't been able to find the solution to this problem.

Upvotes: 1

Views: 5809

Answers (4)

davidxxx
davidxxx

Reputation: 131326

You may use the Scanner that is actually instantiated but not used to chain it with a FileReader instance.
It could allow to have the flexible api of Scanner class that has hasNextLine() and nextLine() methods. 

Scanner in = new Scanner(new FileReader(testDoc));


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

    File testDoc = new File("C:\\TestDocument.txt");
    Scanner in = new Scanner(new FileReader(testDoc));

    try {
        while (in.hasNextLine()) {
            String currentLine = in.nextLine();
            System.out.println(currentLine);
        }
    } finally {
        in.close();
    }
}

Upvotes: 1

ProgrammerBoy
ProgrammerBoy

Reputation: 891

Two ways to do it. See below. 

 File testDoc = new File("C:\\Users\\Te\\Documents\\TestDocument.txt");
    BufferedReader reader = new BufferedReader(new FileReader(testDoc));
    Scanner in = new Scanner(new FileReader(testDoc));
    try {

      //Using Scanner Object
      while(in.hasNextLine()){
          System.out.println(in.nextLine());
      }

    //Using BufferReader Object
      String line=reader.readLine();
      while(line!=null){
          System.out.println(line);
          line=reader.readLine();
      }

    } finally {
      reader.close();
    }

Upvotes: 0

Vasu
Vasu

Reputation: 22384

BufferedReader's (look here) readLine() reads a single line from the file, so you need to write a loop as shown below:

String line = "";
 while((line =reader.readLine()) != null) {
        System.out.println(line);
 }

Also, you don't need Scanner object in your code (if you use BufferedReader), so it would be simply as shown below:

        File testDoc = new File("C:\\Users\\Te\\Documents\\TestDocument.txt");
        BufferedReader reader = new BufferedReader(new FileReader(testDoc));
        try {
             String line = "";
             while((line =reader.readLine()) != null) {
                 System.out.println(line);
             }
        } finally {
          reader.close();
        }

Upvotes: 1

Markus
Markus

Reputation: 1171

The method readLine() just returns one line. So you have to iterate over all lines:

while(reader.hasNextLine()){
    String currentLine = reader.readLine();
}

Upvotes: 0

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