I wanted to make a precise file by deleting unwanted entries using Java

Question

I have two files one contains data and another contains the string. My target is to read the file containing string and see if that string exist in data file and delete that whole row.

Sample data would be :

Data file :

Name='Raj' Age='25' Location='India'

Name='Suresh' Age='26' Location='India'

String file contain : Raj

So when it parse the data file it should delete the first line from data file.

Unless you show what you have done and ask a specific question, the question in the current form is too broad for this site. — Abhay, Apr 22 '15 at 11:39
http://stackoverflow.com/questions/2788080/reading-a-text-file-in-java — EpicPandaForce, Apr 22 '15 at 11:41

score 0 · Answer 1 · answered Apr 22 '15 at 12:02

This is not so difficult, and you haven't post what you have tried. However I am posting a solution for your reference. You can modify/optimize it as per your requirement.

1. First Create a method -

private List<String> getFileContentList(String filePath) {
    List<String> list = new ArrayList<String>();
    try {
        String line;
        BufferedReader br = new BufferedReader(new FileReader(filePath));
        while ((line = br.readLine()) != null) {
            list.add(line);
        }
        br.close();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return list;
}

2. Now do something like below -

List<String> dataList = getFileContentList("C:/DataFile.txt");
List<String> keyList = getFileContentList("C:/KeyFile.txt");        

for (String string1 : keyList) {
    for (int i = 0; i < dataList.size(); i++) {
        if(dataList.get(i).contains(string1)) {
            dataList.remove(i);
        }
    }
}

FileWriter fw;
try {
    fw = new FileWriter("C:/DataFile.txt");
        BufferedWriter bw = new BufferedWriter(fw);
        for (String string : dataList) {
            bw.write(string);
            bw.newLine();
        }
        bw.flush();
        bw.close();
    } catch (IOException e) {
        e.printStackTrace();
    }

I wanted to make a precise file by deleting unwanted entries using Java

1 Answers1