file-io

问题 Imagine having a webservice or servlet , which can perform some fileIO . How can I make sure that if more than one client executes the according WS method, that the fileIO is still handled only by one single "thread"? So that no data is lost because several clients trigger the fileIO? Which direction should I search for? 回答1: The best bet is likely to just make the underlying method(s) that read/write synchronize on a common object. (eg. the File object could be easiest). private static File

问题 I am creating a configuration file on click of a button by the following code. fputs( "AutoStart = " +strAutoWinStart + "AutLogHistory = " +strAutoLogSvrHistory + "AutoScan= " +strAutoScanDetect + "AutoMount = "+ strAutoMount + "AutoOpen = "+ strAutoOpenWin + "LastConnectedSvr = "+ strAutoDetLastConSvr,pFile); and the Output file looks as below: AutoStart = 1AutLogHistory = 0AutoScan= 1AutoMount = 0AutoOpen = 1LastConnectedSvr = 0 Instead I need my output should have a line break in each

问题 I want to work with file streams generically. That is, i want to 'program to an interface and not the implementation'. Something like this: ios * genericFileIO = new ifstream("src.txt"); getline(genericFileIO, someStringObject);//from the string library; dont want to use C strings genericFileIO = new ofstream("dest.txt"); genericFileIO -> operator<<(someStringObject); Is it possible? I am not great with inheritance. Given the io class hierarchy, how do i implement what i want? 回答1: Do you

问题 I want to work with file streams generically. That is, i want to 'program to an interface and not the implementation'. Something like this: ios * genericFileIO = new ifstream("src.txt"); getline(genericFileIO, someStringObject);//from the string library; dont want to use C strings genericFileIO = new ofstream("dest.txt"); genericFileIO -> operator<<(someStringObject); Is it possible? I am not great with inheritance. Given the io class hierarchy, how do i implement what i want? 回答1: Do you

问题 I'm studying the FileLock class. What I want to do is start three Threads that will run at the same time and access a single file. While the file is locked by one thread, I want the other two threads to wait for their turn when the lock is released. However, when I run my code below, the threads don't even start all at the same time--they are started one after the other, as soon as each of their run() methods is finished. I don't understand. public class Main { public static void main(String[

问题 I generate a PDF file within a Sharepoint page; as I have so far been unable to let the user choose a landing spot for the pdf file (as asked about here), I have decided to create a link to the file on the page, hoping that clicking the link will open the file. Here's the code: String pdfFileID = GetYYYYMMDDAndUserNameAndAmount(); String pdfFileName = String.Format("DirectPayDynamic_{0}.pdf", pdfFileID); String fileFullpath Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder

问题 I use the following code to write some data to files: BufferedWriter writer = null; try { writer = new BufferedWriter(new FileWriter(file)); writer.write(...); writer.flush(); } finally { if (writer != null) writer.close(); } After invoking the method multiple times I got a FileNotFoundException because too many files are open. Obviously java does not close the file handles when I close the writer stream. Closing the FileWriter separately does not help. Is there sth. I can do to force java to

问题 I'm trying to get simple file reading in GAE python. I want to allow users to upload a csv file directly from their disk and have it display in a text field. I am having an outrageous amount of trouble doing so. Any help would be appreciated. I would prefer to avoid using the blobstore if possible. I don't want to save the data forever, I just want to use it to allow people to fill the textarea easily. Here's what my form looks like <div class = "section hidden" id ="file_choice"> <form

问题 I'm trying to get simple file reading in GAE python. I want to allow users to upload a csv file directly from their disk and have it display in a text field. I am having an outrageous amount of trouble doing so. Any help would be appreciated. I would prefer to avoid using the blobstore if possible. I don't want to save the data forever, I just want to use it to allow people to fill the textarea easily. Here's what my form looks like <div class = "section hidden" id ="file_choice"> <form

问题 I have an application that creates a text log file using an std::ofstream using std::ofstream::app to create it. This application is writing logs often, sometimes only milliseconds apart. I want to write a second application that reads in and analyses this log file whilst the first application is still writing to it I have some working code, using ifstream , that loads & processes a standalone text log file, but this code fails when I try to use it on the text log file that is currently being