如何访问ThreadPoolExecutor内部正在运行的线程？

我有一个正在运行的线程队列，并且希望在执行时公开其一些数据，以监视进程。

ThreadPoolExecutor提供对其队列的访问，我可以迭代这些对象来调用我的重写toString()方法，但这些只是等待执行的线程。

有没有办法访问当前正在运行的线程来调用我的方法？或者也许有更好的方法来完成这项任务？

为了更清楚地说明其目的，这里有一些总体思路的代码：

public class GetDataTask implements Runnable {
    private String pageNumber;
    private int dataBlocksParsed;
    private String source;
    private String dataType;


    public GetDataTask(String source, String dataType) {
        this.source = source;
        this.dataType = dataType;
    }

    @Override
    public void run() {
        //do stuff that affects pageNumber and dataBlocksParsed
    }

    @Override
    public String toString() {
        return "GetDataTask{" +
            "source=" + source +
            ", dataType=" + dataType +
            ", pageNumber=" + pageNumber +
            ", dataBlocksParsed=" + dataBlocksParsed +
            '}';
    }
}

和一个持有执行者的类：

public class DataParseManager {
    private static ThreadPoolExecutor executor = new ThreadPoolExecutor(100, 100, 20, TimeUnit.SECONDS, new ArrayBlockingQueue<>(300));

    public void addParseDataTask(String source, String dataType) {
        executor.execute(new GetDataTask(source, dataType));
    }

    // here's the method that I need
    public String getInfo() {
        StringBuilder info = new StringBuilder();
        //and here's the method that I'm missing - executor.getActiveThreads()
        for (Runnable r : executor.getActiveThreads()) {
            info.append(((GetDataTask) r).toString()).append('\n');
        }
        return info.append(executor.toString()).toString();
   }
}

像这样包装 Runnable 怎么样？

static class MonitorRunnable implements Runnable {

    static final List<Runnable> activeTasks = Collections.synchronizedList(new ArrayList<>());

    private final Runnable runnable;

    public MonitorRunnable(Runnable runnable) {
        this.runnable = runnable;
    }

    @Override
    public void run() {
        activeTasks.add(runnable);
        runnable.run();
        activeTasks.remove(runnable);
    }
}

and

public class DataParseManager {
    private static ThreadPoolExecutor executor = new ThreadPoolExecutor(100, 100, 20, TimeUnit.SECONDS, new ArrayBlockingQueue<>(300));

    public void addParseDataTask(String source, String dataType) {
        executor.execute(new MonitorRunnable(new GetDataTask(source, dataType)));
    }

    // here's the method that I need
    public String getInfo() {
        StringBuilder info = new StringBuilder();
        //and here's the method that I'm missing - executor.getActiveThreads()
        synchronized (MonitorRunnable.activeTasks) {
            for (Runnable r : MonitorRunnable.activeTasks) {
                info.append(((GetDataTask) r).toString()).append('\n');
            }
        }
        return info.append(executor.toString()).toString();
   }
}