implemented readFromFile(...) according to README.MD requirements

src/main/java/core/basesyntax/FileWork.java

@@ -1,8 +1,43 @@
 package core.basesyntax;
 
+import java.io.BufferedReader;
+import java.io.FileNotFoundException;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.Arrays;
+
 public class FileWork {
+    public static final String SPECIFIED_CHARACTER = "w";
+    public static final String WORDS_DELIMITER = "-";
+    public static final String REGEX_WORD_DIVIDER = "\\W+";
+    public static final String[] EMPTY_ARRAY = new String[0];
+
     public String[] readFromFile(String fileName) {
-        //write your code here
-        return null;
+        StringBuilder stringBuilder = new StringBuilder();
+        try (BufferedReader bufferedReader = new BufferedReader(new FileReader(fileName))) {
+            String line = bufferedReader.readLine();
+            while (line != null) {
+                stringBuilder.append(line).append(System.lineSeparator());
+                line = bufferedReader.readLine();
+            }
+        } catch (FileNotFoundException e) {
+            throw new RuntimeException("File not found.", e);
+        } catch (IOException e) {
+            throw new RuntimeException("Data can't be read", e);
+        }
+        String[] wordsSplit = String.valueOf(stringBuilder).toLowerCase().split(REGEX_WORD_DIVIDER);
+        StringBuilder wordsStartWithSpecifiedCharacter = new StringBuilder();
+        for (String word : wordsSplit) {
+            if (word.startsWith(SPECIFIED_CHARACTER)) {
+                wordsStartWithSpecifiedCharacter.append(word).append(WORDS_DELIMITER);
+            }
+        }
+        if (wordsStartWithSpecifiedCharacter.isEmpty() || String.valueOf(
+                wordsStartWithSpecifiedCharacter).isBlank()) {
+            return EMPTY_ARRAY;
+        }
+        String[] result = String.valueOf(wordsStartWithSpecifiedCharacter).split(WORDS_DELIMITER);
+        Arrays.sort(result);
+        return result;
     }
 }