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Java Forum / First Aid / November 2005J2me, data input stream, Sony Ericsson's K750i,
Hi All, Before optimize the JPG code, here is a branch problem on Sony Ericsson's K750i I don't know why, it seems that very strange, the code will just stop there. I can't sure which line, but it seems stops! ( stay(stop) in a line until I send data from client ) I will find another JSR-82 supported phone, just feel very strange here.. Originally, I want to code as: polling incoming data, when data stops, I will collect them and decode as JPG, but right now, I can't know when it stops... because the code didn't go through~~~ ---------------------------- int bytesToRead = in.available(); if (bytesToRead > 0) { // Initialize buffer byte[] byteBuffer = new byte[bytesToRead]; // Read bytes nbrOfBytesRead = in.read(byteBuffer); ------------ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the code will not go to next line until I send data from clinet @@ do you have the same experiance ? Best regards, Boki. > int bytesToRead = in.available(); > if (bytesToRead > 0) { > // Initialize buffer > byte[] byteBuffer = new byte[bytesToRead]; > // Read bytes > nbrOfBytesRead = in.read(byteBuffer); Please see http://mindprod.com/jgloss/readBlocking.html Your code is probably behaving like a 4 year old, in a tight loop saying, "Can a have cookie now?." "No dear. I have to wait for the bread man to come in his truck." "Can I have a cookie now?" No dear, I have to wait for the bread man to come in his truck."  SignatureCanadian Mind Products, Roedy Green. http://mindprod.com Java custom programming, consulting and coaching. Hi Green, I want to do polling, I don't know the data length first, I want the code can polling data, when there is no more data in a timer time, exit and then show that jpg file. do you mean when I write code as example, and my problem will disappear ? Best regards, Boki. "Roedy Green" <my_email_is_posted_on_my_website@munged.invalid> ???????:gj1ul1t2f80vqss5usr2ju9v48jedtgec6@4ax.com... >> int bytesToRead = in.available(); >> if (bytesToRead > 0) { [quoted text clipped - 9 lines] > bread man to come in his truck." "Can I have a cookie now?" No dear, > I have to wait for the bread man to come in his truck." > I want to do polling, I don't know the data length first, I >want the code can polling data, when there is no more data in a timer time, >exit and then show that jpg file. > >do you mean when I write code as example, and my problem will disappear ? You need a time delay after a getAvailable() == 0 since if you ask right awy there will will rarely be anything for a good many iterations, and you are just gobbling CPU time. Loo at how the code I gave you does it. SignatureCanadian Mind Products, Roedy Green. http://mindprod.com Java custom programming, consulting and coaching. OK, thanks, I will try it :) Best regards, Boki. "Roedy Green" <my_email_is_posted_on_my_website@munged.invalid> ???????:nh4vl1pcnnp8elesdh9qvo7lda5esgpkq4@4ax.com... >> I want to do polling, I don't know the data length first, >> I [quoted text clipped - 9 lines] > > Loo at how the code I gave you does it. > You need a time delay after a getAvailable() == 0 since if you ask > right awy there will will rarely be anything for a good many > iterations, and you are just gobbling CPU time. You don't need a delay if you ask for data in discrete packets rather than asking for one byte at a time: byte[] buffer = new byte[4096]; boolean done = false; while(!done) { int read = istream.read(buffer); if(read != -1) {/* process the bytes received */} else done = true; } No blocking, no fiddling with delays between reads, and the thread will block on InputStream.read() until data is returned. SignatureDarryl L. Pierce <mcpierce@gmail.com> Homepage: http://mcpierce.multiply.com/ "Bury me next to my wife. Nothing too fancy..." - Ulysses S. Grant Very good, it works! btw, nit-pick, it seems that the max incoming data block/packet is 4096 bytes, right? or I have to check that first? Best regards, Boki. "Darryl L. Pierce" <mcpierce@gmail.com> ???????:hW28f.10713$NJ.984@bignews7.bellsouth.net... >> You need a time delay after a getAvailable() == 0 since if you ask >> right awy there will will rarely be anything for a good many [quoted text clipped - 16 lines] > No blocking, no fiddling with delays between reads, and the thread will > block on InputStream.read() until data is returned. I don't know why, sometimes, it can't work again... still be blocked again, my final "read " == 22 ( not -1 ), and then be blocked. Does it possible the K750i's problem? Best regards, Boki. "Boki" <bokiteam@ms21.hinet.net> ¼¶¼g©ó¶l¥ó·s»D:djru9e$72s$1@netnews.hinet.net... > Very good, it works! > [quoted text clipped - 28 lines] >> No blocking, no fiddling with delays between reads, and the thread will >> block on InputStream.read() until data is returned. >still be blocked again, my final "read " == 22 ( not -1 ), and then be >blocked. My readBlocking code has been posted a long time. I have used successfully without incident. I suspect it works. Just use it verbatim. SignatureCanadian Mind Products, Roedy Green. http://mindprod.com Java custom programming, consulting and coaching. >>still be blocked again, my final "read " == 22 ( not -1 ), and then be >>blocked. > > My readBlocking code has been posted a long time. I have used > successfully without incident. I suspect it works. Just use it > verbatim. He's referring to the code I posted in the message to which he was replying... SignatureDarryl L. Pierce <mcpierce@gmail.com> Homepage: http://mcpierce.multiply.com/ "Bury me next to my wife. Nothing too fancy..." - Ulysses S. Grant > I don't know why, > [quoted text clipped - 4 lines] > > Does it possible the K750i's problem? The final read() returns 22 because it read 22 bytes from the input stream. It seems the handset might not be returning -1 (which it should) and is instead blocking waiting for more data when none is available. A change to the code like this should get past it, assuming you know the total size of the incoming data stream: int length = connection.getLength(); byte[] buffer = new byte[4096]; boolean done = false; int totalread = 0; while(!done && totalread < length) { int read = istream.read(buffer); if(read != -1) { totalread += length; /* process the bytes received */ } else done = true; } SignatureDarryl L. Pierce <mcpierce@gmail.com> Homepage: http://mcpierce.multiply.com/ "Bury me next to my wife. Nothing too fancy..." - Ulysses S. Grant Thanks, but I don't know the data length.. because user will send a jpg file ... Best regards, Boki. "Darryl L. Pierce" <mcpierce@gmail.com> ???????:%gn8f.26411$Pp1.25207@bignews3.bellsouth.net... >> I don't know why, >> [quoted text clipped - 26 lines] > else done = true; > } >Thanks, but I don't know the data length.. because user will send a jpg file >... Re-read what I have already given about sockets, http, and readBlocking. The practical answer if you stay baffled in to get the guy written the server code to give you the length both in the http header and just ahead of the jpg image. SignatureCanadian Mind Products, Roedy Green. http://mindprod.com Java custom programming, consulting and coaching. > Thanks, but I don't know the data length.. because user will send a jpg file You're writing the code to send the image, aren't you? Then encode the length in bytes of the image and send that first. SignatureDarryl L. Pierce <mcpierce@gmail.com> Visit my homepage: <http://mcpierce.multiply.com> "By doubting we come to inquiry, through inquiry truth." - Peter Abelard no, due to the image is coming from cmos sensor part, I will not control that part of code. I have already requested it, and they will support that. :) Best regards, Boki. >btw, nit-pick, it seems that the max incoming data block/packet is 4096 >bytes, right? > >or I have to check that first? No. Read just reads a buffer full. It looks at the length of the buffer you give it to know the max you are willing to accept. You may get less, but you won't get more. You don't have to worry about an index out of bounds exception. SignatureCanadian Mind Products, Roedy Green. http://mindprod.com Java custom programming, consulting and coaching. Hi Green, I don't know why, it can't work now.. =========================== while ( !done ) { gui.repaint(); bytesToRead = in.available(); if (bytesToRead > 0 ) { nbrOfBytesRead = in.read(byteBuffer); if ( nbrOfBytesRead == -1 ) done = true ; for (count_jpg=0;count_jpg<nbrOfBytesRead;count_jpg++) { imageData[GUI.ggg+count_jpg]=byteBuffer[count_jpg]; } GUI.ggg+=nbrOfBytesRead; } else if ( GUI.ggg>0 ) done=true; } ======================== The program still be blocked, never exit the while loop even I stop the data transfer a while already... Best regards, Boki. "Roedy Green" <my_email_is_posted_on_my_website@munged.invalid> ???????:ab33m1hfqk2172ibfjkpnkvbmrh55qe5pr@4ax.com... >>btw, nit-pick, it seems that the max incoming data block/packet is 4096 >>bytes, right? [quoted text clipped - 5 lines] > get less, but you won't get more. You don't have to worry about an > index out of bounds exception. > if ( nbrOfBytesRead == -1 ) done = true ; you also want to break out of the look at that point. In that case, you don't need a done boolean. SignatureCanadian Mind Products, Roedy Green. http://mindprod.com Java custom programming, consulting and coaching. got you~ : ) Best regards, Boki. Got you! Best regards, Boki. > Very good, it works! > > btw, nit-pick, it seems that the max incoming data block/packet is 4096 > bytes, right? > > or I have to check that first? The code receives at most 4096 bytes *each time* it reads from the input stream. There's no limit on the size that it will read, it will just do it in discrete packets of 4096 bytes. If there is less than that remaining in the input stream, it will read what's remaining and return. SignatureDarryl L. Pierce <mcpierce@gmail.com> Homepage: http://mcpierce.multiply.com/ "Bury me next to my wife. Nothing too fancy..." - Ulysses S. Grant Got you! Best regards, Boki. >Got you! Hmm. Internet tag. How do you play? I need more exercise. SignatureCanadian Mind Products, Roedy Green. http://mindprod.com Java custom programming, consulting and coaching. play what? "Roedy Green" <my_email_is_posted_on_my_website@munged.invalid> ???????:pe3em1hmu4be2er73mtvfe590ub7pg0oc2@4ax.com... >>Got you! > > Hmm. Internet tag. How do you play? I need more exercise. >play what? > [quoted text clipped - 4 lines] >> >> Hmm. Internet tag. How do you play? I need more exercise. "Internet tag". In the child's running game of tag when you catch someone and touch them you say "got you". SignatureCanadian Mind Products, Roedy Green. http://mindprod.com Java custom programming, consulting and coaching. haha.... I suppose that "Got you".equals("Hey, I get your answer") == true. :D Best regards, Boki. "Roedy Green" <my_email_is_posted_on_my_website@munged.invalid> ???????:99rem1t89paglnu1hhrg82tfnlbgdamq7v@4ax.com... >>play what? >> [quoted text clipped - 7 lines] > "Internet tag". In the child's running game of tag when you catch > someone and touch them you say "got you". Free MagazinesGet these publications absolutely FREE for up to 12 months. There are no hidden fees and no obligation. Simply choose a title, complete the application form and submit it. Read more ...
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