Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.util.Map;
import java.util.Random;
import java.util.UUID;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class Main {
    public static int MAP_SIZE = 100000;

    public static void main(String[] args) {
        Map<String, String> map = new ConcurrentHashMap<String, String>();
        for (int i = 0; i < MAP_SIZE; i++) {
            map.put("key:" + i, UUID.randomUUID().toString());
        }
        ExecutorService executor = Executors.newCachedThreadPool();
        Accessor a1 = new Accessor(map);
        Accessor a2 = new Accessor(map);
        Mutator m = new Mutator(map);
        executor.execute(a1);
        executor.execute(m);
        executor.execute(a2);
    }
}

class Accessor implements Runnable {
    Map<String, String> map;

    public Accessor(Map<String, String> map) {
        this.map = map;
    }

    @Override
    public void run() {
        for (Map.Entry<String, String> entry : this.map.entrySet()) {
            System.out.println(
                    Thread.currentThread().getName() + " - [" + entry.getKey() + ", " + entry.getValue() + ']');
        }
    }
}

class Mutator implements Runnable {
    Map<String, String> map;
    Random random = new Random();

    public Mutator(Map<String, String> map) {
        this.map = map;
    }

    @Override
    public void run() {
        for (int i = 0; i < 100; i++) {
            this.map.remove("key" + random.nextInt(Main.MAP_SIZE));
            this.map.put("key" + random.nextInt(Main.MAP_SIZE), UUID.randomUUID().toString());
            System.out.println(Thread.currentThread().getName() + ": " + i);
        }
    }
}