[Ch15b] Adding timestamp, removing iteration count

package ch15;

import java.time.LocalDateTime;

import java.time.format.FormatStyle;

import java.util.ArrayList;

import java.util.List;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import static java.time.format.DateTimeFormatter.ofLocalizedTime;

public class LotsOfReaders {

  public static void main(String[] args) {

    ChatHistory chatHistory = new ChatHistory();

    ExecutorService executor = Executors.newFixedThreadPool(4);

    ExecutorService executor = Executors.newFixedThreadPool(3);

    for (int i = 0; i < 5; i++) {

      final int iteration = i;

      executor.execute(() -> chatHistory.add("Hi there! " + iteration));

      executor.execute(() -> chatHistory.add("Hi there!"));

      executor.execute(() -> printChatHistory("Reader 1", chatHistory));

      executor.execute(() -> printChatHistory("Reader 2", chatHistory));

    }

class Chat {

  private final String message;

  private final LocalDateTime timestamp;

  public Chat(String message) {

    this.message = message;

    timestamp = LocalDateTime.now();

  }

  @Override

  public String toString() {

    return message;

    String time = timestamp.format(ofLocalizedTime(FormatStyle.MEDIUM));

    return time + " " + message;

  }

}