Stream API

ahilla.txt

RoachDrom         2 1 1 0 1
LongFlight        3 2 2 1 2
Units2D           2 1 1 0 1
Zombies&Demons2D  2 2 3 1 2
SaveUA            2 0 0 1 0
Inovation         0 0 0 0 0
Night&Day         2 1 1 1 1
Нечто             2 2 2 1 3
SpaceCatcher      1 1 2 1 1
Galaxy            1 0 0 0 0
SonicTime3D       3 2 2 0 3
aPlatformer       1 1 0 1 0

bogdang.txt

RoachDrom         0 1 0 1 1
LongFlight        1 2 0 2 1
Units2D           0 1 0 1 0
Zombies&Demons2D  1 2 0 1 1
SaveUA            1 1 0 0 0
Inovation         1 0 0 0 0
Night&Day         1 0 0 1 1
Нечто             0 3 0 2 1
SpaceCatcher      0 1 0 1 1
Galaxy            0 1 0 0 0
SonicTime3D       0 2 0 1 1
aPlatformer       1 1 0 1 1

holdfast.txt

RoachDrom         0 1 1 1 1
LongFlight        1 2 4 2 2 2
Units2D           0 2 1 2 1
Zombies&Demons2D  1 2 3 2 1
SaveUA            1 2 0 2 1
Inovation         0 0 0 0 0
Night&Day         1 3 4 3 2
Нечто             0 3 1 2 2
SpaceCatcher      1 2 2 1 2
Galaxy            0 3 1 1 1
SonicTime3D       0 3 3 2 1
aPlatformer       1 0 0 1 1

Ratings.java

package com.example.stream;

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.stream.Collectors;

public class Ratings {

    public static void main(String[] args) throws IOException {
        Files.list(Paths.get("ratings"))
                .flatMap(path -> readLines(path).stream())
                .map(line -> line.split("\\s+"))
                .map(columns -> IntPair.from(columns[0], calculateSum(columns)))
                .collect(Collectors.groupingBy(IntPair::getFirst)).entrySet().stream()
                .map(entry -> IntPair.from(
                        entry.getKey(),
                        entry.getValue().stream()
                        .mapToInt(IntPair::getSecond)
                        .sum()
                ))
                .sorted(Comparator.<IntPair>comparingInt(IntPair::getSecond).reversed())
                .map(pair -> String.format("%16s: %d", pair.getFirst(), pair.getSecond()))
                .limit(5)
                .forEach(System.out::println);
    }

    private static int calculateSum(String[] columns) {
        return Arrays.stream(columns)
                .skip(1)
                .mapToInt(Integer::parseInt)
                .sum();
    }

    private static List<String> readLines(Path p) {
        try {
            return Files.readAllLines(p, StandardCharsets.UTF_8);
        } catch (IOException ex) {
            return Collections.emptyList();
        }
    }
}

RatingsJ7.java

package com.example.stream;

import java.io.File;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class RatingsJ7 {

    public static void main(String[] args) throws IOException {
        final File[] files = new File("ratings").listFiles();
        Map<String, Integer> projectsGroup = new HashMap<>();
        for (File file : files) {
            List<String> lines = readLines(file.toPath());
            for (String line : lines) {
                IntPair<String> projectInfo = processLine(line);
                final String key = projectInfo.getFirst();
                int rating = projectInfo.getSecond();
                if (projectsGroup.containsKey(key)) {
                    rating += projectsGroup.get(key);
                }
                projectsGroup.put(key, rating);
            }
        }
        List<IntPair<String>> projects = new ArrayList<>();
        for (Map.Entry<String, Integer> entry : projectsGroup.entrySet()) {
            projects.add(IntPair.from(entry.getKey(), entry.getValue()));
        }
        Collections.sort(projects, Comparator.<IntPair>comparingInt(IntPair::getSecond).reversed());

        final int size = Math.min(5, projects.size());
        for (int i = 0; i < size; i++) {
            IntPair<String> project = projects.get(i);
            System.out.format("%16s: %d%n", project.getFirst(), project.getSecond());
        }
    }

    private static IntPair<String> processLine(String line) {
        String[] columns = line.split("\\s+");
        int sum = 0;
        boolean isFirst = true;
        for (String column : columns) {
            if (isFirst) {
                isFirst = false;
                continue;
            }
            sum += Integer.parseInt(column);
        }
        return IntPair.from(columns[0], sum);
    }

    private static List<String> readLines(Path p) {
        try {
            return Files.readAllLines(p, StandardCharsets.UTF_8);
        } catch (IOException ex) {
            return Collections.emptyList();
        }
    }
}