Android 多次执行AsyncTask时发生java.lang.IllegalMonitorStateException

我指的是多次运行异步任务。但是当我调用tryAgain.signal时，我得到了以下错误

下面是我的asyncTask类

public class AsyncHttpRequest extends AsyncTask<Void, String, String> {

    private String UrlString = "";
    private boolean _showProgressDialog = false;
    private ProgressDialog Dialog;
    private Context mContext;
    private IHttpRequestCompletedListener listener;
    private boolean isActivity = true;
    private String _messageText = "Please wait..."; 
    private String type = "get";
    private HttpUtility utility;

    private final ReentrantLock lock = new ReentrantLock();
    private final Condition tryAgain = lock.newCondition();
    private volatile boolean finished = false;
    boolean lockAcquired = false;

    public AsyncHttpRequest(String urlString, Context context, IHttpRequestCompletedListener listener, boolean _showProgressDialog) {
        UrlString = urlString;
        this._showProgressDialog = _showProgressDialog;
        this.mContext = context;
        this.listener = listener;
        Dialog = new ProgressDialog(this.mContext);
        this.utility = new HttpUtility(this.UrlString, mContext, listener);
    }

    public void addGetHeader(String headerData) {
        this.utility.addGetHeader(headerData);
    }

    public void setWaitMessage(String msgText) {
        if (!msgText.equals(""))
            msgText = "\n" + msgText;
        this._messageText = _messageText + msgText;
    }


    @Override
    protected void onPreExecute() {
        if (_showProgressDialog) {
            Dialog.setMessage(this._messageText);
            Dialog.setCancelable(false);
            Dialog.setCanceledOnTouchOutside(false);
            Dialog.show();
        }
    }

    @Override
    protected String doInBackground(Void... params) {
        try {
            String result = "";
            lock.lockInterruptibly();
            do {                
                if (!Utilities.isNetworkAvailable(mContext))
                    result = "No network available";
                else if (this.type.equals("get"))
                    result = utility.doGetRequest();
                else
                    result = utility.doPostRequest();
               
                publishProgress(result);
                tryAgain.await();

            } while (!finished);

            lock.unlock();
            return result;
        } catch (MediCorporateException tex) {            

            if (listener != null) {
                if (isActivity) {
                        ((Activity) mContext).runOnUiThread(new Runnable() {
                            @Override
                            public void run() {
                                listener.OnHttpRequestError();
                            }
                        });
                    } 
                } else {                   
                        ((GcmIntentService) mContext).runOnUIThread(new Runnable() {
                            @Override
                            public void run() {
                                listener.OnHttpRequestError();
                            }
                        });
                    } 
                }
            }
            Utilities.callCrashReport(mContext, tex);
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }finally {
            lock.unlock();
        }
        return "";
    }

    @Override
    protected void onProgressUpdate(String... values) {
        if (this.listener != null) {
            if(values.length > 0) {
                if (!Utilities.isNullOrEmpty(values[0])) {
                    listener.OnHttpRequestCompleted(values[0]);
                    terminateTask();
                } else {                   
                    runAgain();
                }
            }else {
                runAgain();
            }
        }
        Log.i("Exit ", "onProgressUpdate");
    }

    public void runAgain() {
        // Call this to request data from the server again
        tryAgain.signal();
    }

    public void terminateTask() {
        // The task will only finish when we call this method
        if (_showProgressDialog)
            this.Dialog.dismiss();
        finished = true;
        if(lock.isHeldByCurrentThread())
        {
            lock.unlock();
        }
    }

    @Override
    protected void onPostExecute(String Result) {      
        Log.i("Exit ", "onPostExecute");
    }
}

当我从WebService得到空响应时，我再次调用Run，应用程序崩溃。

---

请给出处理此异常的任何解决方案。

您应该在发出呼叫信号之前获取与该条件相关的锁

public void runAgain() {
    // Call this to request data from the server again
    lock.lock();
    try {
        tryAgain.signal();
    } finally {
        lock.unlock();
    }
}

您引用的解决方案有自己的错误

下面是复制自

实施考虑

当调用此方法时，实现可能并且通常确实要求当前线程持有与此条件关联的锁。实现必须记录此先决条件以及未持有锁时所采取的任何操作。通常，会引发异常，例如IllegalMonitorStateException

---

若作业应该多次执行，那个么线程、处理程序或服务可能是比异步任务更好的选择

可能是@FabioBranch的重复，我引用了该线程，但我在实现时遇到了问题。但如何在我的场景中获得锁定？如果我取下锁。解锁；从doInBackground开始，它也会崩溃。

public void runAgain() {
    // Call this to request data from the server again
    lock.lock();
    try {
        tryAgain.signal();
    } finally {
        lock.unlock();
    }
}