release filter out only the words starting with 'w'

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

@@ -1,8 +1,45 @@
 package core.basesyntax;
 
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.Arrays;
+
 public class FileWork {
     public String[] readFromFile(String fileName) {
-        //write your code here
-        return null;
+        if (fileName.isEmpty() || fileName == "") {
+            return new String[0];
+        }
+
+        StringBuilder stringBuilder = new StringBuilder();
+        File file = new File(fileName);
+        String value;
+        try {
+            BufferedReader reader = new BufferedReader(new FileReader(file));
+            value = reader.readLine();
+            while (value != null) {
+                stringBuilder.append(value).append(System.lineSeparator());
+                value = reader.readLine();
+            }
+        } catch (IOException e) {
+            throw new RuntimeException("Can`t read file", e);
+        }
+        if (stringBuilder.length() == 0) {
+            return new String[0];
+        }
+        String[] strings = stringBuilder.toString().toLowerCase().split("\\W+");
+        stringBuilder.setLength(0);
+        for (String str : strings) {
+            if (str.charAt(0) == 'w') {
+                stringBuilder.append(str).append(System.lineSeparator());
+            }
+        }
+        if (stringBuilder.length() > 0) {
+            String[] result = stringBuilder.toString().split(System.lineSeparator());
+            Arrays.sort(result);
+            return result;
+        }
+        return new String[0];
     }
 }