CODEWITHSUNDEEP
javafile-iostream
Addison Waege
Addison Waege

Reputation: 49

Reading a words from file with a stream

I am trying to read the words of a file into a stream and the count the number of times the word "the" appears in the file. I cannot seem to figure out an efficient way of doing this with only streams.

Example: If the file contained a sentence such as: "The boy jumped over the river." the output would be 2

This is what I've tried so far

public static void main(String[] args){

    String filename = "input1";
    try (Stream<String> words = Files.lines(Paths.get(filename))){
        long count = words.filter( w -> w.equalsIgnoreCase("the"))
                .count();
        System.out.println(count);
    } catch (IOException e){

    }
}

Upvotes: 1

Views: 2199

Answers (3)

harikrish
harikrish

Reputation: 9

Use the stream reader to calculate the number of words.

Upvotes: -1

Pshemo
Pshemo

Reputation: 124235

Just line name suggests Files.lines returns stream of lines not words. If you want to iterate over words I you can use Scanner like

Scanner sc = new Scanner(new File(fileLocation));
while(sc.hasNext()){
    String word = sc.next();
    //handle word
}

If you really want to use streams you can split each line and then map your stream to those words 

try (Stream<String> lines = Files.lines(Paths.get(filename))){
    long count = lines
            .flatMap(line->Arrays.stream(line.split("\\s+"))) //add this
            .filter( w -> w.equalsIgnoreCase("the"))
            .count();
    System.out.println(count);
} catch (IOException e){
    e.printStackTrace();//at least print exception so you would know what wend wrong
}

BTW you shouldn't leave empty catch blocks, at least print exception which was throw so you would have more info about problem.

Upvotes: 1

hinson
hinson

Reputation: 151

You could use Java's StreamTokenizer for this purpose.

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.StreamTokenizer;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;

public class Main {

    public static void main(String[] args) throws IOException {
      long theWordCount = 0;
      String input = "The boy jumped over the river.";
      try (InputStream stream = new ByteArrayInputStream(
             input.getBytes(StandardCharsets.UTF_8.name()))) {
        StreamTokenizer tokenizer = 
          new StreamTokenizer(new InputStreamReader(stream));
            int tokenType = 0;
            while ( (tokenType = tokenizer.nextToken()) 
               != StreamTokenizer.TT_EOF) {
                if (tokenType == StreamTokenizer.TT_WORD) {
                    String word = tokenizer.sval;
                    if ("the".equalsIgnoreCase(word)) {
                        theWordCount++;
                    }
                }
            }
        }
        System.out.println("The word 'the' count is: " + theWordCount);
    }
}

Upvotes: 0

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