CODEWITHSUNDEEP
javafileprintingcomparedifference
Acotrica3
Acotrica3

Reputation: 11

Compare 2 *.txt files and print difference between them

I have a problem wrtting the code for comparing two files (first reference file): 

       PROTOCOL STATE SERVICE
       1        open  icmp
       6        open  tcp
       17       open  udp

and (execution file)

      PROTOCOL STATE  SERVICE
      1        open   icmp
      6        open   tcp
      17       open   udp
      255      closed unknown

and save difference between these two files in new file (255 closed unknown).

For comparing I have used following code but it seems it doesn't work.

public String[] compareResultsAndDecide(String refFile, String execFile) throws IOException {

    String[] referenceFile = parseFileToStringArray(refFile);
    String[] execCommand = parseFileToStringArray(execFile);
    List<String> tempList = new ArrayList<String>();


    for(int i = 1; i < execCommand.length ; i++)
    {
        boolean foundString = false; // To be able to track if the string was found in both arrays
        for(int j = 1; j < referenceFile.length; j++)
        {
            if(referenceFile[j].equals(execCommand[i]))
            {
                foundString = true; 
                break; // If it exist in both arrays there is no need to look further
            }
        }
        if(!foundString) // If the same is not found in both..
            tempList.add(execCommand[i]); // .. add to temporary list
    }



    String diff[] = tempList.toArray(new String[0]);


    if(diff != null)  {

                    return diff;
    }

For String refFile I would use /home/xxx/Ref.txt path to reference file. And the same for execFile (second file shown up). Anyone can help me with this?

Just to add, I'm using for parsing File to String Array:

public String[] parseFileToStringArray(String filename) throws FileNotFoundException {
    Scanner sc = new Scanner(new File(filename));
    List<String> lines = new ArrayList<String>();
    while (sc.hasNextLine()) {
                    lines.add(sc.nextLine());
    }
    String[] arr = lines.toArray(new String[0]);
    return arr;
}

Upvotes: 1

Views: 1946

Answers (3)

ThisaruG
ThisaruG

Reputation: 3412

Problem is in your .txt files. Your encoding must be different.

I know this isn't the best way, but if you use replaceAll() method to replace white spaces from your lines of text files, your code should work. But Unfortunately, you will miss the spaces between lines.

Change:

String[] arr = lines.toArray(new String[0]);

To:

String[] arr = lines.toArray(new String[0]).replaceAll(" ", "");

Note:

  1. I tried using trim() but it didn't worked well for me.
  2. As I mentioned above, array elements starts from 0, not from 1. Change that too.

Upvotes: 0

Eritrean
Eritrean

Reputation: 16498

your compareResultsAndDecide method has to be changed like :

public static String[] compareResultsAndDecide(String refFile, String execFile) throws IOException {

    String[] referenceFile = parseFileToStringArray(refFile);
    String[] execCommand = parseFileToStringArray(execFile);
    List<String> tempList = new ArrayList<String>();

    List<String> diff = new ArrayList(Arrays.asList(execCommand));
    diff.removeAll(Arrays.asList(referenceFile));
    String[] toReturn = new String[diff.size()];
    toReturn = diff.toArray(toReturn);
    return toReturn;
}

and your parseFileToStringArray like:

    public String[] parseFileToStringArray(String filename) throws FileNotFoundException {
        Scanner sc = new Scanner(new File(filename));
        List<String> lines = new ArrayList<String>();
        while (sc.hasNextLine()) {
            lines.add(sc.nextLine());
        }
        String[] arr = new String[lines.size()];
        return lines.toArray(arr);
    }

Upvotes: 0

AmitB10
AmitB10

Reputation: 423

Change int i = 1 to int i = 0 and int j = 1 to int j = 0

Upvotes: 1

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