filewriter

问题 I have a CSV log file and it contains many rows like this: 2016-06-21 12:00:00,000 : helloworld: header1=2;header2=6;header=0 I want to write them to a new CSV file. public void readLogFile() throws Exception { String currentLine = ""; String nextLine = ""; BufferedReader reader = new BufferedReader(new FileReader(file(false))); while ((currentLine = reader.readLine()) != null) { if (currentLine.contains("2016") == true) { nextLine = reader.readLine(); if (nextLine.contains("helloworld") ==

问题 I have a CSV log file and it contains many rows like this: 2016-06-21 12:00:00,000 : helloworld: header1=2;header2=6;header=0 I want to write them to a new CSV file. public void readLogFile() throws Exception { String currentLine = ""; String nextLine = ""; BufferedReader reader = new BufferedReader(new FileReader(file(false))); while ((currentLine = reader.readLine()) != null) { if (currentLine.contains("2016") == true) { nextLine = reader.readLine(); if (nextLine.contains("helloworld") ==

问题 I have a CSV log file and it contains many rows like this: 2016-06-21 12:00:00,000 : helloworld: header1=2;header2=6;header=0 I want to write them to a new CSV file. public void readLogFile() throws Exception { String currentLine = ""; String nextLine = ""; BufferedReader reader = new BufferedReader(new FileReader(file(false))); while ((currentLine = reader.readLine()) != null) { if (currentLine.contains("2016") == true) { nextLine = reader.readLine(); if (nextLine.contains("helloworld") ==

问题 I have a CSV log file and it contains many rows like this: 2016-06-21 12:00:00,000 : helloworld: header1=2;header2=6;header=0 I want to write them to a new CSV file. public void readLogFile() throws Exception { String currentLine = ""; String nextLine = ""; BufferedReader reader = new BufferedReader(new FileReader(file(false))); while ((currentLine = reader.readLine()) != null) { if (currentLine.contains("2016") == true) { nextLine = reader.readLine(); if (nextLine.contains("helloworld") ==

问题 I am attempting to create a simple text file that I will be writing to. I receive the following error: /Library/Java/Home/bin/java -Didea.launcher.port=7542 "-Didea.launcher.bin.path=/Applications/IntelliJ IDEA 14 CE.app/Contents/bin" -Dfile.encoding=UTF-8 -classpath "/Library/Java/Home/lib/deploy.jar:/Library/Java/Home/lib/dt.jar:/Library/Java/Home/lib/javaws.jar:/Library/Java/Home/lib/jce.jar:/Library/Java/Home/lib/jconsole.jar:/Library/Java/Home/lib/management-agent.jar:/Library/Java/Home

问题 Ok so I am learning about I/O, and I found the following code in one of the slides. can someone please explain why there is a need to have a FileWrite, BufferedWriter and PrintWriter? I know BufferedWriter is to buffer the output and put it all at once but why would they use FileWriter and PrintWriter ? dont they pretty much do the same with a bit of difference in error handling etc? And also why do they pass bw to PrintWriter ? FileWriter fw = new FileWriter (file); BufferedWriter bw = new

问题 Ok so I am learning about I/O, and I found the following code in one of the slides. can someone please explain why there is a need to have a FileWrite, BufferedWriter and PrintWriter? I know BufferedWriter is to buffer the output and put it all at once but why would they use FileWriter and PrintWriter ? dont they pretty much do the same with a bit of difference in error handling etc? And also why do they pass bw to PrintWriter ? FileWriter fw = new FileWriter (file); BufferedWriter bw = new

问题 I have a method that is supposed to overwrite the current file with new content, however the FileWriter() is only appending the new content, not overwriting the old content. This is how my FileWriter is set up File file = new File(test.txt); BufferedWriter out; out = new BufferedWriter(new FileWriter(file, false)); Here is the save method //stuff is defined earlier and filled with the new content for the file ArrayList<String> stuff = new ArrayList<>(); //The actual save() method Object[]

问题 im trying to take data from my sqlite database and write it into csv file and email the information when done writing.i only have one Table with 3 columns in the database.i have DBAdapter and a class that have the Button that the user must press to be able to export the data. Here is the code i have tried Exportdata.java try { root = Environment.getExternalStorageDirectory(); Log.i(TAG,"path.." +root.getAbsolutePath()); //check sdcard permission if (root.canWrite()) { File fileDir = new File

问题 This question already has answers here : BufferedWriter not writing everything to its output file (8 answers) Closed 4 years ago . I am trying to get input from a JOptionPane and store what the user typed into a text file using the FileWriter class.To make sure that the input from what the user typed was being stored I wrote a system.out and what I typed in the JOptionPane appears. Unfortunately when I open the .txt file nothing I entered appears! By the way, the file path I entered is