[java] append file

[perzem]

ho creato questa funzione per salvare su di un file dei dati. Esiste un metodo per eseguire un append in fondo al file per poter salvare dati di sessioni di lavoro diverse??

public boolean salva(){
try{
ObjectOutputStream out=new ObjectOutputStream(new FileOutputStream("pag.txt"));
out.writeObject(el.toString());
out.close();
}catch(Exception e){return false;}
return true;}

[Angelo1974]

Ciao semplicemente dovresti fare:

public boolean salva(){
try{
ObjectOutputStream out=new ObjectOutputStream(new FileOutputStream("pag.txt", true));
out.writeObject(el.toString());
out.close();
}catch(Exception e){return false;}
return true;} 

Mettendo true setti in modalità append il FileOutpuStream:

public FileOutputStream(File file,
                        boolean append)
                 throws FileNotFoundExceptionCreates a file output stream to write to the file represented by the specified File object. If the second argument is true, then bytes will be written to the end of the file rather than the beginning. A new FileDescriptor object is created to represent this file connection. 
First, if there is a security manager, its checkWrite method is called with the path represented by the file argument as its argument. 

If the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason then a FileNotFoundException is thrown. 


Parameters:
file - the file to be opened for writing.
append - if true, then bytes will be written to the end of the file rather than the beginning 
Throws: 
FileNotFoundException - if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason 
SecurityException - if a security manager exists and its checkWrite method denies write access to the file.
Since: 
1.4 

Ciao