package sundemo2;

 import java.io.File;

 import java.io.FileReader;

 import java.io.FileWriter;  

 public class MainClass{

     public static void main(String[] args) throws Exception{

         FileManager a = new FileManager("E:\\WorkSpace\\SunDemo\\data\\demo\\a.txt",new char[]{'\n'});

         FileManager b = new FileManager("E:\\WorkSpace\\SunDemo\\data\\demo\\b.txt",new char[]{'\n',' '});

         FileWriter c = new FileWriter("E:\\WorkSpace\\SunDemo\\data\\demo\\c.txt");

         String aWord = null;

         String bWord = null;

         while((aWord = a.nextWord()) !=null ){

             c.write(aWord + "\n");

             bWord = b.nextWord();

             if(bWord != null)

                 c.write(bWord + "\n");

         }  

         while((bWord = b.nextWord()) != null){

             c.write(bWord + "\n");

         }

         c.close();

     }

 }  

 class FileManager{

     String[] words = null;

     int pos = 0;

     public FileManager(String filename,char[] seperators) throws Exception{

         File f = new File(filename);

         FileReader reader = new FileReader(f);

         char[] buf = new char[(int)f.length()];

         int len = reader.read(buf);

         String results = new String(buf,0,len);

         String regex = null;

         if(seperators.length > 1 ){

             regex = "" + seperators[0] + "|" + seperators[1];

         }else{

             regex = "" + seperators[0];

         }

         words = results.split(regex);

     }  

     public String nextWord(){

         if(pos == words.length)

             return null;

         return words[pos++];

     }

 }