Wicket sometimes makes things easier for us that we forget what's under the hood :)
Remember that most of your implementation is already thread safe and synced on the Page. Read more about the request cycle in the free guide at: http://wicket.apache.org/guide/guide/chapter8.html So you want to perform a long running operation in a separate thread? Try this post: http://javathoughts.capesugarbird.com/2008/04/spawning-thread-for-lengthy-operation.html Have a great day, Paul Bors > On Dec 30, 2013, at 6:32 PM, eaglei22 <jchojnack...@gmail.com> wrote: > > Hello, I am having an issue when using a worker thread to process a csv file. > I have asked the same question here: > > http://stackoverflow.com/questions/20747605/requestcycle-goes-null-when-using-a-separate-thread > > and I wanted to post here as I feel there are not many Wicket programmers > there. > > > The main issue seems to be when I process a large csv file I get a read > error. But if I process a smaller one I do not. Here is the stack trace: > > java.io.IOException: Read error > at java.io.FileInputStream.readBytes(Native Method) > at java.io.FileInputStream.read(FileInputStream.java:220) > at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:264) > at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:306) > at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:158) > at java.io.InputStreamReader.read(InputStreamReader.java:167) > at java.io.BufferedReader.read1(BufferedReader.java:185) > at java.io.BufferedReader.read(BufferedReader.java:261) > at java.io.BufferedReader.fill(BufferedReader.java:136) > > Dec 30 13:14:31 ERROR BulkLoadPage-java.io.IOException: Read error > at java.io.BufferedReader.readLine(BufferedReader.java:299) > at java.io.BufferedReader.readLine(BufferedReader.java:362) > at au.com.bytecode.opencsv.CSVReader.getNextLine(CSVReader.java:266) > at au.com.bytecode.opencsv.CSVReader.readNext(CSVReader.java:233) > at com..wicket.BulkLoadPage.processLine(BulkLoadPage.java:547) > at com..wicket.BulkLoadPage.access$0(BulkLoadPage.java:532) > at > > > com..wicket.BulkLoadPage$BatchLoaderProcessingThread.run(BulkLoadPage.java:1294) > at java.lang.Thread.run(Thread.java:662) > > > > I basically have a listView that is being updated by the main thread using > AjaxSelfUpdatingTimer - set to update every 1 second. The worker thread > which is an inner runnable class uses the methods of the main class, and > updates the arrayList which is also stored in the main class and used by the > listView. > > I was originally getting a requestCycle error, which seemed to be resolved > by commenting out my feedbackPanel error message inside my catch. That error > seemed to be produced from a read error produced by the reference to the > CSVReader. The file being read in contains many lines. I believe around 15k. > Every line has the same data which I copied and pasted just to test a large > file. The file seems to work fine when it is less than 2k.. so I am thinking > maybe it is a sychronization issue or some issue with data interleaving. > > I had designed this page not knowing there would be issues with larger files > using a thread.. there is a lot of functionality and there is no issues with > a small file as stated.. just larger ones. The only job of the thread is to > call a method from the main thread. That method loops through and processes > the CSV file, and when that ends.. the thread dies. Should I be using local > variables in the thread? Or what are some steps I can take to > troubleshooting this error? Or is there a better way I should approach this > to having a worker thread process results while the main thread uses a > listView to display results. A dataView was reccommended and I will try that > as well, but I am not sure if I can use a worker thread with that or not. > > Thank you. > > > > -- > View this message in context: > http://apache-wicket.1842946.n4.nabble.com/MultiThreading-issues-with-Wicket-tp4663325.html > Sent from the Users forum mailing list archive at Nabble.com. > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org > For additional commands, e-mail: users-h...@wicket.apache.org > --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org For additional commands, e-mail: users-h...@wicket.apache.org
