P3123 Popov Egor task-3

src/main/java/ru/ifmo/cet/javabasics/WarAndPeaceExercise.java

@@ -1,12 +1,19 @@
 package ru.ifmo.cet.javabasics;
 
+import java.io.*;
+import java.nio.charset.Charset;
+import java.nio.file.Files;
+import java.util.*;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 
 
 public class WarAndPeaceExercise {
 
-    public static String warAndPeace() {
+    public static String warAndPeace() throws IOException{
         final Path tome12Path = Paths.get("src", "main", "resources", "WAP12.txt");
         final Path tome34Path = Paths.get("src", "main", "resources", "WAP34.txt");
 
@@ -15,7 +22,30 @@ public static String warAndPeace() {
         // TODO Entries in final String should be also sorted by amount and then in alphabetical order iff needed.
         // TODO Also omit any word with lengths less than 4 and frequency less than 10
 
-        throw new UnsupportedOperationException();
-    }
+        Stream<String> textInLines = Stream.concat(Files.lines(tome12Path.toAbsolutePath(), Charset.forName("windows-1251")), Files.lines(tome34Path.toAbsolutePath(), Charset.forName("windows-1251")));
+
+        StringBuilder end = new StringBuilder();
 
+        textInLines.map(String::toLowerCase).map(lines -> {
+            return lines.replaceAll("[^а-яa-z]", " ");
+        })
+                .flatMap(lines -> {
+                    return Arrays.stream(lines.split(" "));
+                })
+                .filter(word -> {
+                    return word.length() > 3;
+                })
+                .collect(Collectors.groupingBy(Function.identity(),Collectors.counting()))
+                .entrySet()
+                .stream()
+                .filter(word -> {
+                    return word.getValue() >= 10;
+                })
+                .sorted((o1, o2) -> {
+                    return (o1.getValue().compareTo(o2.getValue()) == 0) ? o1.getKey().compareTo(o2.getKey()) : -(o1.getValue()).compareTo(o2.getValue());
+                })
+                .forEach(word -> end.append(word.getKey()).append(" - ").append(word.getValue()).append("\n"));
+
+        return end.toString().trim();
+    }
 }