Apache Commons IO - LineIterator Class

Overview

LineIterator class provides a flexible way to work with a line-based file.

Class Declaration

Following is the declaration for org.apache.commons.io.LineIterator Class −

public class LineIterator
   extends Object implements Iterator<String>, Closeable

Usage of LineIterator

Get LineIterator using FileUtils.

try(LineIterator lineIterator = FileUtils.lineIterator(file)) {
...
}

Check if line exists using lineIterator.hasNext() method

while(lineIterator.hasNext()) {
...
}

Get the line contents using LineIterator.next() method

String lineContents = lineIterator.next()

Here is the input file we need to parse −

input.txt

Welcome to TutorialsPoint. Simply Easy Learning.
Learn web technologies,
prepare exams,
code online,
all at one place.

Example - Print each line of file using LineIterator class

CommonsIoTester.java

package com.tutorialspoint;

import java.io.File;
import java.io.IOException;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.LineIterator;

public class CommonsIoTester {
   public static void main(String[] args) throws IOException {
      //get the file object
      File file = FileUtils.getFile("input.txt");
      try(LineIterator lineIterator = FileUtils.lineIterator(file)) {
         System.out.println("Contents of input.txt");
         while(lineIterator.hasNext()) {
            System.out.println(lineIterator.next());
         }
      }
   }
}

Output

It will print the following result −

Contents of input.txt
Welcome to TutorialsPoint. Simply Easy Learning.
Learn web technologies,
prepare exams,
code online,
all at one place.