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    <p>In this post I'll provide you with two completely different approaches to solving your problem, and depending on your use case one of the solutions will fit better than the other.</p> <p><strong>Alternative #1</strong></p> <p>This method is memory efficient though quite complex, if you are going to skip a lot of contents this method is recommended since you only will store one line at a time in memory during processing.</p> <p>The implementation of it in this post might not be <strong>super</strong> optimized, but the theory behind it stands clear.</p> <p>You will start by reading the file backwards, searching for N number of line breaks. When you've successfully located where in the file you'd like to stop your processing later on you will jump back to the beginning of the file.</p> <p><strong>Alternative #2</strong></p> <p>This method is easy to comprehend and is very straight forward. During execution you will have N number of lines stored in memory, where N is the number of lines you'd like to skip in the end.</p> <p>The lines will be stored in a FIFO container (<em>First In, First Out</em>). You'll append the last read line to your FIFO and then remove and process the first entry. This way you will always process lines at least N entries away from the end of your file.</p> <hr> <hr> <h1>Alternative #1</h1> <p>This might sound odd but it's definitely doable and the way I'd recommend you to do it; start by reading the file <strong>backwards</strong>.</p> <ol> <li>Seek to the end of the file</li> <li>Read (and discard) bytes (towards the beginning of the file) until you've found <code>SKIP_N</code> line breaks</li> <li>Save this position</li> <li>Seek to the beginning of the file</li> <li>Read (and process) lines until you've come down to the position you've stored away</li> </ol> <hr> <h2>Example code:</h2> <p>The code below will strip off the last <code>42</code> lines from <code>/tmp/sample_file</code> and print the rest using the method described earlier in this post.</p> <pre><code>import java.io.RandomAccessFile; import java.io.File; import java.lang.Math; public class Example { protected static final int SKIP_N = 42; public static void main (String[] args) throws Exception { File fileHandle = new File ("/tmp/sample_file"); RandomAccessFile rafHandle = new RandomAccessFile (fileHandle, "r"); String s1 = new String (); long currentOffset = 0; long endOffset = findEndOffset (SKIP_N, rafHandle); rafHandle.seek (0); while ((s1 = rafHandle.readLine ()) != null) { ; currentOffset += s1.length () + 1; // (s1 + "\n").length if (currentOffset &gt;= endOffset) break; System.out.println (s1); } } protected static long findEndOffset (int skipNLines, RandomAccessFile rafHandle) throws Exception { long currentOffset = rafHandle.length (); long endOffset = 0; int foundLines = 0; byte [] buffer = new byte[ 1024 &gt; rafHandle.length () ? (int) rafHandle.length () : 1024 ]; while (foundLines &lt; skipNLines &amp;&amp; currentOffset != 0) { currentOffset = Math.max (currentOffset - buffer.length, 0); rafHandle.seek (currentOffset); rafHandle.readFully (buffer); for (int i = buffer.length - 1; i &gt; -1; --i) { if (buffer[i] == '\n') { ++foundLines; if (foundLines == skipNLines) endOffset = currentOffset + i - 1; // we want the end to be BEFORE the newline } } } return endOffset; } } </code></pre> <hr> <hr> <h1>Alternative #2</h1> <ol> <li>Read from your file line by line</li> <li>On every successfully read line, insert the line at the back of your <code>LinkedList&lt;String&gt;</code></li> <li>If your <code>LinkedList&lt;String&gt;</code> contains more lines than you'd like to skip, remove the first entry and process it</li> <li>Repeat until there are no more lines to be read</li> </ol> <hr> <h2>Example code</h2> <pre><code>import java.io.InputStreamReader; import java.io.FileInputStream; import java.io.DataInputStream; import java.io.BufferedReader; import java.util.LinkedList; public class Example { protected static final int SKIP_N = 42; public static void main (String[] args) throws Exception { String line; LinkedList&lt;String&gt; lli = new LinkedList&lt;String&gt; (); FileInputStream fis = new FileInputStream ("/tmp/sample_file"); DataInputStream dis = new DataInputStream (fis); InputStreamReader isr = new InputStreamReader (dis); BufferedReader bre = new BufferedReader (isr); while ((line = bre.readLine ()) != null) { lli.addLast (line); if (lli.size () &gt; SKIP_N) { System.out.println (lli.removeFirst ()); } } dis.close (); } } </code></pre>
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    1. COwaiting for your code thanks! I didn't know you can read from file until stored position
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    2. CO@markiz Sorry it took so long, I'm still at work and got caught up doing other things. The sample solution got a bit messy, I apologize for that, kept running back and forth between my personal computer and a work related things.
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    3. CO@markiz Added further explanation of the theory used, I also wrote a different alternative solution using the theory discussed in other posts in this thread. Which of the solutions suits you better depends on the context.
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