Java supports several file-reading features. One such utility is reading a specific line in a file. 

We can do this by simply providing the desired line number; the stream will read the text at that location.





The **`Files`** class can be used to read the $nth$ line of a file.

# Small files

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

class FileRead {
    public static void main( String args[] ) {
      int n = 1; // The line number
      try{
        String line = Files.readAllLines(Paths.get("file.txt")).get(n);
        System.out.println(line);
      } 
      catch(IOException e){
        System.out.println(e);
      }
    }
}

The **`readAllLines` method** returns a list of strings where​ each string is a line of text in the specified file. **`get(n)`** retrieves the string for the $nth$ line.

>**Note:** The method has to be put inside a `try-catch` block in order to handle IO exceptions.

# Large files

Once upon a midnight dreary, while I pondered, weak and weary,
Over many a quaint and curious volume of forgotten lore—
    While I nodded, nearly napping, suddenly there came a tapping,
As of some one gently rapping, rapping at my chamber door.
“’Tis some visitor,” I muttered, “tapping at my chamber door—
            Only this and nothing more.”

    Ah, distinctly I remember it was in the bleak December;
And each separate dying ember wrought its ghost upon the floor.
    Eagerly I wished the morrow;—vainly I had sought to borrow
    From my books surcease of sorrow—sorrow for the lost Lenore—
For the rare and radiant maiden whom the angels name Lenore—
            Nameless here for evermore.

    And the silken, sad, uncertain rustling of each purple curtain
Thrilled me—filled me with fantastic terrors never felt before;
    So that now, to still the beating of my heart, I stood repeating
    “’Tis some visitor entreating entrance at my chamber door—
Some late visitor entreating entrance at my chamber door;—
            This it is and nothing more.”

    Presently my soul grew stronger; hesitating then no longer,
“Sir,” said I, “or Madam, truly your forgiveness I implore;
    But the fact is I was napping, and so gently you came rapping,
    And so faintly you came tapping, tapping at my chamber door,
That I scarce was sure I heard you”—here I opened wide the door;—
            Darkness there and nothing more.

    Deep into that darkness peering, long I stood there wondering, fearing,
Doubting, dreaming dreams no mortal ever dared to dream before;
    But the silence was unbroken, and the stillness gave no token,
    And the only word there spoken was the whispered word, “Lenore?”
This I whispered, and an echo murmured back the word, “Lenore!”—
            Merely this and nothing more.

    Back into the chamber turning, all my soul within me burning,
Soon again I heard a tapping somewhat louder than before.
    “Surely,” said I, “surely that is something at my window lattice;
      Let me see, then, what thereat is, and this mystery explore—
Let my heart be still a moment and this mystery explore;—
            ’Tis the wind and nothing more!”

    Open here I flung the shutter, when, with many a flirt and flutter,
In there stepped a stately Raven of the saintly days of yore;
    Not the least obeisance made he; not a minute stopped or stayed he;
    But, with mien of lord or lady, perched above my chamber door—
Perched upon a bust of Pallas just above my chamber door—
            Perched, and sat, and nothing more.

Then this ebony bird beguiling my sad fancy into smiling,
By the grave and stern decorum of the countenance it wore,
“Though thy crest be shorn and shaven, thou,” I said, “art sure no craven,
Ghastly grim and ancient Raven wandering from the Nightly shore—
Tell me what thy lordly name is on the Night’s Plutonian shore!”
            Quoth the Raven “Nevermore.”

    Much I marvelled this ungainly fowl to hear discourse so plainly,
Though its answer little meaning—little relevancy bore;
    For we cannot help agreeing that no living human being
    Ever yet was blessed with seeing bird above his chamber door—
Bird or beast upon the sculptured bust above his chamber door,
            With such name as “Nevermore.”

    But the Raven, sitting lonely on the placid bust, spoke only
That one word, as if his soul in that one word he did outpour.
    Nothing farther then he uttered—not a feather then he fluttered—
    Till I scarcely more than muttered “Other friends have flown before—
On the morrow he will leave me, as my Hopes have flown before.”
            Then the bird said “Nevermore.”

    Startled at the stillness broken by reply so aptly spoken,
“Doubtless,” said I, “what it utters is its only stock and store
    Caught from some unhappy master whom unmerciful Disaster
    Followed fast and followed faster till his songs one burden bore—
Till the dirges of his Hope that melancholy burden bore
            Of ‘Never—nevermore’.”

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.stream.*;

class FileRead {
    public static void main( String args[] ) {
      int n = 40; // The line number
      String line;
      try (Stream<String> lines = Files.lines(Paths.get("file.txt"))) {
        line = lines.skip(n).findFirst().get();
        System.out.println(line);
      }
      catch(IOException e){
        System.out.println(e);
      }
    }
}

In the code above, **`lines.skip`** is used to jump `n` lines from the start of the file. Just as before, the `get()` method returns a string.

# Java 7
For Java 7 users, the `BufferedReader` class can be used to retrieve a particular line of text.

import java.io.IOException;
import java.io.FileReader;
import java.io.BufferedReader;

class FileRead {
    public static void main( String args[] ) {
      int n = 40; // The line number
      String line;
      try (BufferedReader br = new BufferedReader(new FileReader("file.txt"))) {
          for (int i = 0; i < n; i++)
              br.readLine();
          line = br.readLine();
          System.out.println(line);
      }
      catch(IOException e){
        System.out.println(e);
      }
    }
}

Reading the Nth line from a file in Java

Use Java's Files class to read the nth line of a file using readAllLines or lines.skip with try-catch for exceptions. Java 7 users can use BufferedReader.