Crash

[Jeffin21]

java.lang.NullPointerException:
at java.io.File.fixSlashes (File.java:185)
at java.io.File. (File.java:134)
at com.liulishuo.filedownloader.download.DownloadRunnable.run (DownloadRunnable.java:121)
at com.liulishuo.filedownloader.download.DownloadLaunchRunnable.realDownloadWithSingleConnection (DownloadLaunchRunnable.java:593)
at com.liulishuo.filedownloader.download.DownloadLaunchRunnable.run (DownloadLaunchRunnable.java:294)
at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:587)
at java.lang.Thread.run (Thread.java:818)

[Jacksgong]

@Jeffin21 可否告知下版本号?

[Jeffin21]

latest version

[Jeffin21]

v1.7.1

[Jacksgong]

@Jeffin21 可否告知下具体哪个版本的Android系统，我查下File的源码，这个问题比较奇怪。

[Jeffin21]

Samsung Galaxy J2 (2018) (j2y18lte), 1536MB RAM, Android 7.1

[Jeffin21]

i added codes for this #949 issue by @rantianhua

[Jeffin21]

5646236 e45ffa5

[Jacksgong]

@Jeffin21 thanks for your issue, but this crash is different with #949 . It seems that something wrong on File.java, which has been discussed on here .

[Jeffin21]

it happens on 7.0 and above

[Jeffin21]

this crash happens in so many above 7.0 devices , i only gave one device sample to you

[Jacksgong]

@Jeffin21 Okay, thanks, I test FileDownloader sample project on devices 8.0.0 can't reproduce such crash, and check the source code(only match 4.2.2 source code, 7.1.0 or 7.0 didn't provide File.java source, and 6.0 source can't match 185 line number you provide), and on the 4.2.2 source code indicate only if we provide null on File constructor such as new File(null) can produce such problem. But DownloadRunnable.java(121) you provide can't match any possible line number on v1.7.1.

[Jeffin21]

I'll check and let you know about this later. Thank You

[Jacksgong]

@Jeffin21 so, could you please provide the real code on DownloadRunnable.java:121? you can decompile your apk to find it, or find it by real dependency code in your project.

[Jeffin21]

FileDownloadDatabase database = CustomComponentHolder.getImpl().getDatabaseInstance();
database.updateConnectionCount(downloadId, 1);
new File(path).delete();

@Jacksgong this code in that place

[Jacksgong]

so... you change the code? I don't think the following logic is the originDownloadRunnable.java does:

 /*  throw new SocketException(FileDownloadUtils.
         formatString(
                 "Connection failed with request[%s] response[%s] "
                         + "http-state[%d] on task[%d-%d], which is changed"
                         + " after verify connection, so please try again.",
                 connectTask.getRequestHeader(),
                 connection.getResponseHeaderFields(),
                 code, downloadId, connectionIndex));*/

 //FileDownloader.getImpl().pause(downloadId);
 TasksManagerDBController task = new TasksManagerDBController();
 TasksManagerModel model = task.getItemByID(String.valueOf(downloadId));
 String path = model.getPath();

 if(PreferenceHelper.getToastMsgService(GDMApplication._appContext,downloadId)==0) {
     System.out.println("download runnable:");
     PreferenceHelper.setToastMsgService(GDMApplication._appContext, 1, downloadId);
 }

 FileDownloadDatabase database = CustomComponentHolder.getImpl().getDatabaseInstance();
 database.updateConnectionCount(downloadId, 1);
 new File(path).delete();

[Jeffin21]

Yes , i changed the code. i told you before need a feature. Some URLs like dailymotion video they dont support multidownload the only way to download that files is to 1st check multi threading is supported if not it go to give upretry expection and we again try to download with single thread and it workds we made some changes for our need

[Jacksgong]

• First of all, on here, because of codes changed I don't know why model.getPath() is null on here, you please finger out by yourself.
• Secondly, I have already told you the solution and cause, and the worst plan is if the download failed on the first time for the task, just change the connection count for it by ConnectionCountAdapter, you can do such things very clean.

finally, if you think the solution you provide is nice the PR is very welcome.

[Jeffin21]

we did with ConnectionCountAdapter and that wont work in our case

[Jacksgong]

@Jeffin21 If the second time it doesn't invoke ConectionCountAdapter to judge the connection count, you can invoke FileDownloader#clear(id, path) to clear data of it on error callback scope.

[Jeffin21]

Let me try it . Thanks