在文本文件中查找单词并计算特定单词

Question

now I'll try to explain what I need to do. I have file.txt file, It looks like:

John //first line - name
One
Three
Four

Peter //first line - name
Two
Three

Elisa //first line - name
One
Three

Albert //first line - name
One
Three
Four

Nicole //first line - name
Two
Four

So I have program's code:

 public class Testing {


        public static void main(String args[]) throws Exception {
            Scanner input = new Scanner(System.in);
            System.out.println("Select word from list:");
            System.out.println();

            try {
                FileReader fr = new FileReader("src/lt/kvk/i3_2/test/List.txt"); // this is list of words, everything all right here
                BufferedReader br = new BufferedReader(fr);
                String s;
                while((s = br.readLine()) != null) {
                    System.out.println(s);
                }
                fr.close();
                String stilius = input.nextLine();   // eneter word which I want to count in File.txt
                BufferedReader bf = new BufferedReader(new FileReader("src/lt/kvk/i3_2/test/File.txt")); // from this file I need to count word which I entered before

                int counter = 0;                
                String line;

                System.out.println("Looking for information");
                while (( line = bf.readLine()) != null){
                    int indexfound = line.indexOf(stilius);
                    if (indexfound > -1) {
                         counter++;
                    }

                }
                if (counter > 0) {
                    System.out.println("Word are repeated "+ counter + "times");}
                    else {
                    System.out.println("Error...");
                }
                bf.close(); 

            }
            catch (IOException e) {
                System.out.println("Error:" + e.toString());
                }
            }
        }

This program counting specific word (entered by keyboard) in file.txt.

I need to make this program: for ex.: if I enter word: One It must show:

Word One repeated 3 times by John, Elisa, Albert

All what I need to elect by who this word repeated. But I don't know really how to make It, maybe LinkedList or I dont know, someone could help me?

Thank you very much.

Answer 1

You can have a List<String> that holds where your word was repeated, and add elements to it on the fly.

To add elements to it you can use an extra variable lastName (of type String ), and in your while loop, do something like:

if (line.trim().length() == 0) lastName = null; 
else if (lastName == null) lastName = line;

The first line if for "resetting" the lastName variable, after you changes the name of the name (assuming there is an empty line after all the words of each name)
The second line is setting it back to the new name after an empty line.

And in addition when you increase counter do:

myList.add(lastName)

So the loop will be something like that:

List<String> resultList = new ArrayList<String>();
String lastName = null;
while (( line = bf.readLine()) != null){
   if (line.trim().length() == 0) lastName = null;
   else if (lastName == null) lastName = line;
   int indexfound = line.indexOf(stilius);
   if (indexfound > -1) {
      counter++;
      resultList.add(lastName);
   }
//do something with resultList, which contains the names
}

Answer 2

I'd suggest you to use Map<String, Set<String>> where key is a word and value is the list of people names that "typed" this word.

So, here is how you can define your collection:

Map<String, Set<String>> word2people = HashMap>();`

Here is how you can add words there:

String name = ...
String word = ...
Set<String> people = word2people.get(word);
if (people == null) {
    people = new HashSet<String>();
    word2people.put(people);
}
people.add(name);

And here is how you can retrieve the value:

word2people.get(word)