sequencial numbers in mapreduce <p>I have written a Java code to create RowId in Java. But I need to convert it into mapreduce. I am new to MapReduce and need your help.</p> <p>Input is a file in local</p> <pre><code>example: Alex 23 M NY Alex 19 M NJ Alex 29 M DC Michael 20 M NY Michael 24 M DC </code></pre> <p>Count file providing as secondary input Example:</p> <pre><code>Alex 3 Michael 2 Desired Output: 1 Alex 23 M NY 2 Alex 19 M NJ 3 Alex 29 M DC 1 Michael 20 M NY 2 Michael 24 M DC </code></pre> <p>My code in Java is here:</p> <pre><code>public class RowId { public static void main( String [] args) throws IOException { BufferReader in = null; BufferReader cnt = null; BufferWriter out = null; String in_line; String out_line; int frst_row_ind=1; int row_cnt=0; int new_col=0; try{ in= BufferReader(new FileReader ("file path in local"); File out_file = new File("o/p path in local"); if(!out_file.exists()){ out_file.createNewFile(); } FileWriter fw = new FileWriter(out_file); out = new BufferWriter(fw); while((in_line = in.readLine())! = null) { if (in_line!=null) { String[] splitData = in_line.split("\\t"); cnt = new BufferReader(new FileReader("file path of countFile") while((cnt_line=cnt.readLine()) != null ) { String[] splitCount = cnt_line.split("\\t"); if ((splitCount[0]).equalsIgnoreCase(splitData[0])) { if (frst_row_ind==1) { row_cnt = Integer.parseInt(splitCount[1]); } new_col++ out.write(String.valueOf(new_col)); out.write("\\t"); for(int i= 0; i &lt;splitData.length; i++) { if (!(splitData[i] == null) || (splitData[i].length()== 0)) { out.write(splitData[i].trim()); if (i!=splitData.length-1) { out.write("\\t"); } } } row_cnt--; out.write("\r\n"); if(row_cnt==0) { frst_row_ind=1; new_col=0; } else{ frst_row_ind=0; } out.flush(); break; } } } } } catch (IOException e) { e.printStrackTrace(); } finally { try{ if(in!=null) in.close(); if(cnt !=null) cnt.close(); } catch (IOException e) { e.printStrackTrace(); } } } } </code></pre> <p>Please do revert with your idea(s).</p>