Performance/CarNumberGenerator/src/Loader.java - master - Nicholas/java_basics

Performance/CarNumberGenerator/src/Loader.java
52 строки2 KB
Nicholay Sokolovsky
20.1 Performance
11 дек 2023, 20:19
11 дек 2023, 20:19d0ab8e2
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;

public class Loader {
    public static void main(String[] args) {
        long start = System.currentTimeMillis();
        char letters[] = {'У', 'К', 'Е', 'Н', 'Х', 'В', 'А', 'Р', 'О', 'С', 'М', 'Т'};
        ThreadPoolExecutor pool = (ThreadPoolExecutor) Executors.newFixedThreadPool(12);

        for (int regionCode = 1; regionCode < 100; regionCode++) {
            int finalRegionCode = regionCode;
            pool.execute(() -> {
                try {
                    PrintWriter writer = new PrintWriter("res/numbers".concat(Integer.toString(finalRegionCode)).concat(".txt"));
                    StringBuilder builder = new StringBuilder();
                    for (int number = 1; number < 1000; number++) {
                        for (char firstLetter : letters) {
                            for (char secondLetter : letters) {
                                for (char thirdLetter : letters) {
                                    builder.append(firstLetter).append(padNumber(number, 3)).append(secondLetter)
                                            .append(thirdLetter).append(padNumber(finalRegionCode, 2)).append('\n');
                                }
                            }
                        }
                    }
                    writer.write(builder.toString());
                    writer.flush();
                    writer.close();
                    if (pool.getActiveCount() == 1) {
                        System.out.println((System.currentTimeMillis() - start) + " ms");
                    }
                } catch (FileNotFoundException e) {
                    throw new RuntimeException(e);
                }
            });
        }
        pool.shutdown();
    }

    private static String padNumber(int number, int numberLength) {
        String numberStr = Integer.toString(number);
        int padSize = numberLength - numberStr.length();
        if (padSize > 0) {
            for (int i = 0; i < padSize; i++) {
                numberStr = "0".concat(numberStr);
            }
        }
        return numberStr;
    }
}