Question

I have one method {search()} that search for a particular file in a directory that the filename start by "B" and it will return the files. I have 2 file that start by B [Bcc.txt, Ba.txt]. But in main method I want to count a word "light" how many times it appeares in the each files [Bcc.txt, Ba.txt]. However, I really don't know how to do it. I need help on that.

public class CountWord {

   public static void main(String[] args) {

   System.out.println(search()); //it will print [Bcc.txt, Ba.txt]

   }

   public static String search() {

   File root = new File("/Users");

   FilenameFilter beginswithm = new FilenameFilter() {

   public boolean accept(File directory, String filename) {

   return filename.startsWith("B");

   }

   };

   String[] files = root.list(beginswithm);

   if(files==null)

   return "No Files";

   else

   return Arrays.toString(files);

  

   }

}

Answer 1

Code:

package countoccur;

import java.io.File;
import java.io.FilenameFilter;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.AbstractMap.SimpleEntry;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class CountOccur {
   public static void main(String[] args) throws IOException {
       String[] files = search();
       String word = "light";

//Read lines and split by space
       Files.lines(Paths.get("/Users/" + files[0])).flatMap(line -> Stream.of(line.split(" ")))

//Convert to lower case each line
   .map(String::toLowerCase)

//Filter whether word matches
.filter(w -> w.equalsIgnoreCase(word))

//Count the occureence, just add an entry to map of each occurrence
   .collect(Collectors.toMap(words -> words, words -> 1, Integer::sum))

//Get the values
   .entrySet()

//Create a stream out of it
   .stream()

//Count the occurrence
   .sorted((a, b) -> a.getValue() == b.getValue() ? a.getKey().compareTo(b.getKey()) : b.getValue() - a.getValue())
   .forEach(System.out::println);
   }

   public static String[] search() { // Returning array to iterate through the file
       File root = new File("/Users/");
       FilenameFilter beginswithm = new FilenameFilter() {
           public boolean accept(File directory, String filename) {
               return filename.startsWith("m");
           }
       };
       String[] files = root.list(beginswithm);
       if (files == null)
           return null; // No file found
       else
           return files; // returning array of file which contains B

   }
}

Sample Output:

d thanks.jsp A d UserDB.java A Userjava 0D 。 web.xml ·면 EmailList.txt EmailListServlet.java index.jsp index.jsp CountoOccur.java "sorted ((a, b) -> a.getvalue() .forEach(System.out::println); b.getvalue() ? a.getKey()"compareTo ( b . getKey ( )) : b.getvalue () -a.getvalue()) public static String[] search) t // Returning array to iterate through the file File root-new File("/Users/"); FilenameFilter beginswithmnew FilenameFilter) i public boolean accept (File directory, String filename) return filename.startsWith ("m"); 1; String[] files root.list(beginswithm); if (files null) return null; // No file found else return files; // returning array of file which contains rch Results Output CountOccur (run)Usages run: a1-2 BUILD SUCCESSFUL (total time: 0 seconds)

Please comment for doubts.