java - How to find similar lines in two text files irrespective of the line number at which they occur -

i trying open 2 text files , find similar lines in them. code correctly reading lines both text files. have used nested for loops compare line1 of first text file lines of second text file , on. however, detecting similar lines have same line number, (eg. line 1 of txt1 cc cc cc , line 1 of txt2 cc cc cc, correctly finds , prints it), doesn't detect same lines on different line numbers in files.

import java.io.*; import java.util.*;  public class featureselection500 {      public static void main(string[] args) throws filenotfoundexception, ioexception {         // todo code application logic here          file f1 = new file("e://implementation1/practise/comupdatusps.exe.hex-04-ngrams-freq.txt");         file f2 = new file("e://implementation1/practise/top-300features.txt");          scanner scan1 = new scanner(f1);          scanner scan2 = new scanner(f2);          int = 1;         list<string> txtfileone = new arraylist<string>();          list<string> txtfiletwo = new arraylist<string>();          while (scan1.hasnext()) {             txtfileone.add(scan1.nextline());         }          while (scan2.hasnext())          {              txtfiletwo.add(scan2.nextline());         }      /*     for(string ot : txtfiletwo )     {     (string output : txtfileone)      {        // if (txtfiletwo.contains(output))         if(output.equals(ot))         {             system.out.print(i + " ");              system.out.println(output);            i++;           }      }     } */          (int j = 0; j < txtfiletwo.size(); j++) {              string fsl = txtfiletwo.get(j);             //  system.out.println(filecontentsingleline);              (int z = 0; z < 600; z++)                                 // z < txtfileone.size()             {                 string s = txtfileone.get(z);                 //  system.out.println(fsl+"\t \t"+ s);                 if (fsl.equals(s)) {                     system.out.println(fsl + "\t \t" + s);                     // line                      // system.out.println(fsl);                 } else {                     continue;                 }             }         }     } } 

i made code nicer, you're welcome :) anyway, don't understand bug. runs through of list2 every line in list1...

import java.io.*; import java.util.*; public class featureselection500 {    public static void main(string[] args) throws filenotfoundexception, ioexception {     // todo code application logic here      file file1 = new file("e://implementation1/practise/comupdatusps.exe.hex-04-ngrams-freq.txt");     file file2 = new file("e://implementation1/practise/top-300features.txt");      scanner scan1 = new scanner(file1);      scanner scan2 = new scanner(file2);      list<string> txtfile1 = new arraylist<string>();      list<string> txtfile2 = new arraylist<string>();      while (scan1.hasnext()) {         txtfile1.add(scan1.nextline());     }      while (scan2.hasnext()) {         txtfile2.add(scan2.nextline());     }     (int = 0; < txtfile2.size(); i++) {         string linei = txtfile2.get(i);         //  system.out.println(filecontentsingleline);         (int j = 0; j < txtfile1.size(); j++){ // z < txtfileone.size(             string linej = txtfile1.get(j);             //  system.out.println(fsl+"\t \t"+ s);             if (linei.equals(linej)) {                 system.out.println(linei + "\t \t" + linej);                 // line                  // system.out.println(fsl);             }         }      }   } }