Question

I have two files Which should contain the same values between Substring 0 and 10 though not in order. I have Managed to Outprint the values in each file but I need to Know how to Report say id the Value is in the first File and Notin the second file and vice versa. The files are in these formats.

6436346346....Other details
9348734873....Other details
9349839829....Other details

second file

8484545487....Other details
9348734873....Other details
9349839829....Other details

The first record in the first file does not appear in the second file and the first record in the second file does not appear in the first file. I need to be able to report this mismatch in this format:

Record 6436346346 is in the firstfile and not in the secondfile.
Record 8484545487 is in the secondfile and not in the firstfile.

Here is the code I currently have that gives me the required Output from the two files to compare.

package compare.numbers;

import java.io.*;

/**
 *
 * @author implvcb
 */
 public class CompareNumbers {

/**
 * @param args the command line arguments
 */
 public static void main(String[] args) {
    // TODO code application logic here
    File f = new File("C:/Analysis/");
    String line;
    String line1;
    try {
        String firstfile = "C:/Analysis/RL001.TXT";
        FileInputStream fs = new FileInputStream(firstfile);
        BufferedReader br = new BufferedReader(new InputStreamReader(fs));
        while ((line = br.readLine()) != null) {
            String account = line.substring(0, 10);
             System.out.println(account);


        }
        String secondfile = "C:/Analysis/RL003.TXT";
        FileInputStream fs1 = new FileInputStream(secondfile);
        BufferedReader br1 = new BufferedReader(new InputStreamReader(fs1));
        while ((line1 = br1.readLine()) != null) {
            String account1 = line1.substring(0, 10);
            System.out.println(account1);
        }

    } catch (Exception e) {
        e.fillInStackTrace();
    }



}
}

Please help on how I can effectively achieve this.
I think I needed to say that am new to java and may not grab the ideas that easily but Am trying.

Answer 1

Here is the sample code to do that:

 public static void eliminateCommon(String file1, String file2) throws IOException
{
    List<String> lines1 = readLines(file1);
    List<String> lines2 = readLines(file2);

    Iterator<String> linesItr = lines1.iterator();
    while (linesItr.hasNext()) {
        String checkLine = linesItr.next();
        if (lines2.contains(checkLine)) {
            linesItr.remove();
            lines2.remove(checkLine);
        }
    }

    //now lines1 will contain string that are not present in lines2
    //now lines2 will contain string that are not present in lines1
    System.out.println(lines1);
    System.out.println(lines2);

}

public static List<String> readLines(String fileName) throws IOException
{
    List<String> lines = new ArrayList<String>();
    FileInputStream fs = new FileInputStream(fileName);
    BufferedReader br = new BufferedReader(new InputStreamReader(fs));
    String line = null;
    while ((line = br.readLine()) != null) {
        String account = line.substring(0, 10);
        lines.add(account);
    }
    return lines;
}