Every day I update a csv file using a FileWriter
. When we step into a new month I have to delete the data from the previous month. My below code only updates a data in a csv file so, please help in deleting the previous month's data.
At least I need to know how to delete the data in csv file using FileWriter
, so that I can manage to code for deleting previous month data.
private static void eventsUpdate(HttpServletRequest request, HttpServletResponse response) { String date=request.getParameter("date"); //getting from jsp page String event=request.getParameter("event"); //getting from jsp page File file = new File( "D:///events/events.csv"); if ( !file.exists() ) file.createNewFile(); FileWriter fw = new FileWriter(file,true); BufferedWriter writer = new BufferedWriter( fw ); writer.write(date); writer.write(","); writer.write(event); System.out.println("writing into excel"); writer.newLine(); writer.close(); fw.close(); }
Pantelis Nat.. 5
Actually when you use the true
argument in your FileWriter
instantiation, you create a file writer object in append mode.
FileWriter fw = new FileWriter(file,false);
如果您不使用该true
选项,则文件将被新内容覆盖。因此,我建议遵循以下路线图:
整体读取文件内容 String
从特定内容中删除您要删除的内容 String
使用特定内容中的新内容覆盖文件内容 String
希望我能帮上忙!
Actually when you use the true
argument in your FileWriter
instantiation, you create a file writer object in append mode.
FileWriter fw = new FileWriter(file,false);
如果您不使用该true
选项,则文件将被新内容覆盖。因此,我建议遵循以下路线图:
整体读取文件内容 String
从特定内容中删除您要删除的内容 String
使用特定内容中的新内容覆盖文件内容 String
希望我能帮上忙!