filewriter

问题 I have a question in my mind that, while writing into the file, before closing is done, should we include flush()??. If so what it will do exactly? dont streams auto flush?? EDIT: So flush what it actually do? 回答1: Writers and streams usually buffer some of your output data in memory and try to write it in bigger blocks at a time. flushing will cause an immediate write to disk from the buffer, so if the program crashes that data won't be lost. Of course there's no guarantee, as the disk may

问题 I'm currently using FileWriter to create and write to a file. Is there any way that I can write to the same file every time without deleting the contents in there? fout = new FileWriter( "Distribution_" + Double.toString(_lowerBound) + "_" + Double.toString(_highBound) + ".txt"); fileout = new PrintWriter(fout,true); fileout.print(now.getTime().toString() + ", " + weight + ","+ count +"\n"); fileout.close(); 回答1: Pass true as a second argument to FileWriter to turn on "append" mode. fout =

问题 I am seeking to clarify what the Java API documentation states about the FileWriter class. The documentation states the following: constructor: Constructs a FileWriter object given a file name. public FileWriter(String fileName) throws IOException fileName - String The system-dependent filename. IOException - if the named file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened or any other reason It is not clear to me whether or not

问题 It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 6 years ago . good day guys, im creating a program that will write the data to a text file. the data is coming from an array list, it is a data that is solved from the array list e.g : public double getGincome(){ gincome=rpd

问题 In my file writer, I have these codes, the j == 4 and j == 8 is to execute a different code for the column that contains numbers for(int i=0; i<model.getRowCount();i++){ for(int j=0; j<model.getColumnCount();j++){ if(j==4 || j==8){ excelWriter.write("\""+model.getValueAt(i, j) + "\t"+"\""); } else{ excelWriter.write(model.getValueAt(i, j) + "\t"); } } excelWriter.write("\n"); } the problem is after that column with number had been printed, the next column will not be printed.. for example

问题 In my code, write stuff to file using this code //the path String fileName = Environment.getExternalStoragePublicDirectory(fileName) + File.separator+"Foo"+File.separator; File dir = new File(fileName); //the file fileName += "bar" File file = new File(fileName); try { file.createNewFile(); } catch (IOException e) { //do nothing, for now } return; This results with the file being written /storage/emulated/0/ and not to /storage/sdcard0 . The problem I have with this is that I dont see

问题 I am always curious how a rolling file is implemented in logs. How would one even start creating a file writing class in any language in order to ensure that the file size is not exceeded. The only possible solution I can think of is this: write method: size = file size + size of string to write if(size > limit) close the file writer open file reader read the file close file reader open file writer (clears the whole file) remove the size from the beginning to accommodate for new string to

问题 New to Phonegap and having a hard time understanding the FileWriter function. I am trying to get this example to work on iOS6 but I'm stuck with the error message <script type="text/javascript" charset="utf-8" src="cordova-2.3.0.js"></script> <script type="text/javascript" charset="utf-8"> var fileWriter; function onNotesLoad() { window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, onFSComplete, fail); } function onFSComplete(fileSystem) { // Load the notes.txt file, create it if it doesn

问题 Question is in the Title, Here's my code which dosen't seem to work: File counterValues = new File(getClass().getResource(COUNTER_VALUES_FILE).getFile()); FileWriter out = new FileWriter(counterValues); out.write("TEST"); out.close(); where COUNTER_VALUES_FILE is private static final String COUNTER_VALUES_FILE = "/data/counter_values.csv"; I have also tried: File counterValues = new File(getClass().getResource(COUNTER_VALUES_FILE).toURI()); It has made me believe it might not be possible, but

问题 In my application, list of Image files is inflated in recyclerview. Then after application edits the metadata of Image file. My code for writing metadata:- DocumentFile fos = DocumentFile.fromFile(new File(fileIn)); ByteSource bytsInputStream = new ByteSourceFile(new File(fileIn)); byte[] byteArrayInputStream = bytsInputStream.getAll(); try { ParcelFileDescriptor pfd = context.getContentResolver(). openFileDescriptor(fos.getUri(), "w"); FileOutputStream fileOutputStream = new FileOutputStream