File fileO = new File("d://writer.txt");

File fileI = new File("d://read.txt");

FileInputStream   in=new FileInputStream(fileI );

FileOutputStream  out=new FileOutputStream(fileO ,true);

 

 byte[]b=new byte[12];

            int len=0;

            while((len=in.read(b))!=-1){

                out.write(b, 0, len);

            }

            in.close();

            out.close();

写： File file = new File("d://anjuke.txt");

FileOutputStream fos = new FileOutputStream(file,true);

OutputStreamWriter out = new OutputStreamWriter(fos); for(AJKCommunity community : listComm){
     out.write(community.toString());    out.write("\n");               } out.close(); fos.close();