Java Thread - 如何InputStream上的并发读取

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class Main {
  public static void main(String[] args) throws IOException {
    ExecutorService service = Executors.newFixedThreadPool(4);
    BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in));
    String line;
    while ((line = buffer.readLine()) != null) {
      service.execute(new Worker(line));
    }
  }
}

class Worker implements Runnable {
  private final String line;
  public Worker(String line) {
    this.line = line;
  }
  @Override
  public void run() {
    System.out.println("Processing line: " + line);
  }
}