package notes; import java.io.BufferedReader; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.FileReader; import java.io.IOException; public class scan { public static void main(String[] args) { StringBuffer inputBuffer = new StringBuffer(); try { BufferedReader file = new BufferedReader(new FileReader(args[0])); String line; while ((line = file.readLine()) != null) { if(line.startsWith("sr-due")){ line = "sr-due: " + (line.substring(8, 12)) + "-" + (line.substring(12, 14)) + "-" + (line.substring(14, 16)); } inputBuffer.append(line); inputBuffer.append('\n'); } file.close(); try { // write the new string with the replaced line OVER the same file FileOutputStream fileOut = new FileOutputStream(args[0]); fileOut.write(inputBuffer.toString().getBytes()); fileOut.close(); } catch (FileNotFoundException e) { System.out.println("error writing"); } } catch (FileNotFoundException e) { System.out.println(e.getMessage()); } catch (IOException e) { System.out.println("io exception"); } } }