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    copied!<p>By taking RandomAccessFile you can:</p> <ul> <li>use method <strong>seek(long)</strong> to jump forward and read those lines. But you won't know exactly how big the jump should be.</li> <li>to delete last lines you need the position of begin of last line so before reading each line store their file pointer position (method <strong>getFilePointer()</strong>). Deleting to that position you use <strong>setLength(long)</strong>.</li> </ul> <p>Code would be something like this:</p> <pre><code> LinkedList&lt;String&gt; lines=null; int howMuch = 1; // one line to read and delete try{ RandomAccessFile raf = new RandomAccessFile(inputFileName, "rw"); System.out.println("File Length="+raf.length()); long step = 20; // here I advice to write average length of line long jump = raf.length()&lt;step*howMuch? 0: raf.length()-step*howMuch; raf.seek(jump); lines = new LinkedList&lt;String&gt;(); LinkedList&lt;Long&gt; pos = new LinkedList&lt;Long&gt;(); Entry&lt;LinkedList&lt;String&gt;,LinkedList&lt;Long&gt;&gt; rLinesRead = getRemainingLines(raf, new AbstractMap.SimpleEntry&lt;LinkedList&lt;String&gt;,LinkedList&lt;Long&gt;&gt; (lines,pos)); while(rLinesRead.getKey().size()&lt;howMuch){ if(jump&lt;step) if(jump&lt;=0) break; else{ jump=0; raf.seek(jump); rLinesRead=getRemainingLines(raf,rLinesRead); break; } else jump=jump-step; raf.seek(jump); rLinesRead=getRemainingLines(raf,rLinesRead); } int originalSize=rLinesRead.getKey().size(); lines=rLinesRead.getKey(); pos=rLinesRead.getValue(); for (int i=0;i&lt;originalSize-howMuch;++i){ lines.removeFirst(); pos.removeFirst(); } if(!pos.isEmpty()) raf.setLength(pos.getFirst()); // before last(from EOF) returned fully read lines in file }catch(Exception ex){ ex.printStackTrace(); } finally{ try { raf.close(); } catch (Exception e) { e.printStackTrace(); } } //returns line to EOF with their begin file pointer positions private Entry&lt;LinkedList&lt;String&gt;,LinkedList&lt;Long&gt;&gt; getRemainingLines(RandomAccessFile raf, Entry&lt;LinkedList&lt;String&gt;,LinkedList&lt;Long&gt;&gt; linesAlreadyLoadedFromEnd) throws IOException{ LinkedList&lt;String&gt; pLines = linesAlreadyLoadedFromEnd.getKey(); LinkedList&lt;Long&gt; pPos = linesAlreadyLoadedFromEnd.getValue(); long init=raf.getFilePointer(); String str = raf.readLine(); if(pPos.size()&gt;0?pPos.getFirst()==0:false || str==null) return linesAlreadyLoadedFromEnd; LinkedList&lt;String&gt; lines = new LinkedList&lt;String&gt;(); LinkedList&lt;Long&gt; pos = new LinkedList&lt;Long&gt;(); if(init==0L ){ lines.add(str); pos.add(0L); } Long tmpPos = raf.getFilePointer(); while ((str = raf.readLine())!=null &amp;&amp; !pPos.contains(tmpPos)){ lines.add(str); pos.add(tmpPos); tmpPos = raf.getFilePointer(); } pLines.addAll(0,lines); pPos.addAll(0,pos); return new AbstractMap.SimpleEntry&lt;LinkedList&lt;String&gt;,LinkedList&lt;Long&gt;&gt; (pLines,pPos); } </code></pre>
 

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