java - Linux vs. Windows File.delete() -

i'm having bit of trouble understanding how windows handles files compared linux. i'm trying remove entry in file i'm using "database" (it's regular file). java unfortunately offers no method doing this, have copy entries except 1 want delete temporary file, delete old database, create new empty database file, copy contents of temporary file new database file, , finish off deleting temporary.

here's code function:

private void removeselecteditem(string entrytoremove) {      //original database file     file database = new file("catalog");      //all entries except selected written here first     file temp = new file("temp");      boolean endoffileflag = false;     string line = "";      try {          //used reading original database file         bufferedreader databasereader =             new bufferedreader(new filereader(database));          //used writing newly-created temp file         bufferedwriter tempwriter =             new bufferedwriter(new filewriter(temp, true));          /*          * read original database line line , test see if line          * has course prefix , id. if does, won't written          * temp file.          */         while (endoffileflag == false) {              line = databasereader.readline();              /*              * code ugly. if possible, check needs              * made in conditions of while loop.              */             if (line == null) {                  endoffileflag = true;                 break;              }              //tests see if line removed             if ( !line.contains(entrytoremove))                 tempwriter.write(line + "\r\n");          }          endoffileflag = false; //reset next loop         databasereader.close(); //database deleted         tempwriter.close(); //temp file written         database.delete(); //delete create new updated 1 below          database.createnewfile();          //writes new database         bufferedwriter databasewriter =                 new bufferedwriter(new filewriter(database, true));          //reads temp file         bufferedreader tempreader =             new bufferedreader(new filereader(temp));          //read temp line line , add each line new catalog file         while (endoffileflag == false) {              line = tempreader.readline();              /*              * code ugly. if possible, check needs made              * in conditions of while loop. attempts far have              */             if(line == null){                  endoffileflag = true;                 break;              }              databasewriter.write(line + "\r\n");          }          tempreader.close(); //temp deleted         databasewriter.close(); //new database has been written         temp.delete(); //temp file no longer needed          setupinfo(); //update lists new catalog info      }catch(ioexception e){          system.out.println("removeselecteditem()");         e.printstacktrace();      }  } 

this code (for exception of "\r\n," in linux "\n") executes under linux, in windows found when activate event handler removing entry, program add entries. after debugging found call database.delete() isn't deleting database file, while call temp.delete() deleting temporary file (like it's supposed to). found odd checked permissions of file , set "read/write." tried following fix found on internet:

endoffileflag = false; //reset next loop databasereader.close(); //database deleted tempwriter.close(); //temp file written database.delete(); //delete create new updated 1 below //new code database = null; system.gc(); 

but didn't work. can't think of else happening.

afaik, no os supports deleting part of file (except end)

you can't delete file have open have sure closed everywhere, can create temporary file , rename original. (no need copy back)

here how might write it

public static void removeline(string filename, string line) {     file = new file(filename);     file tmp = new file(filename + ".tmp");     printwriter pw = null;     bufferedreader br = null;     try {         pw = new printwriter(tmp);         br = new bufferedreader(new filereader(from));         boolean found = false;         (string line2; (line2 = br.readline()) != null; )             if (line2.equals(line))                 found = true;             else                 pw.println(line2);         pw.close();         br.close();         if (found) {             from.delete();             tmp.renameto(from);         } else {             tmp.delete();         }     } catch (ioexception e) {         // log error.         try { if (br != null) br.close(); } catch (ioexception ignored) { }         if (pw != null) pw.close();     } }