public static String getLatestLines(File file) throws IOException {
long s = System.currentTimeMillis();
BufferedReader br = null;
List<String> list = new ArrayList<>();
StringBuilder sb = new StringBuilder();
try {
br = new BufferedReader(new FileReader(file));
String line;
while ((line = br.readLine()) != null) {
list.add(line + "\n");
}
int lastIndex = getLastIndex(list);
for (int i = lastIndex; i < list.size(); i++) {
sb.append(list.get(i));
}
} catch (FileNotFoundException ex) {
Logger.getLogger(LogfileUtil.class.getName()).log(Level.SEVERE, null, ex);
} finally {
try {
br.close();
} catch (IOException ex) {
Logger.getLogger(LogfileUtil.class.getName()).log(Level.SEVERE, null, ex);
}
}
long e = System.currentTimeMillis();
log.log(
Level.OFF,
"Deserialized log file, elapsed: {0} seconds",
AdministratorServlet.getElapsed(s, e));
return sb.toString();
}
public static String lineByLine(File file) throws IOException {
long s = System.currentTimeMillis();
BufferedReader br = null;
List<String> list = new ArrayList<>();
StringBuilder sb = new StringBuilder();
try {
br = new BufferedReader(new FileReader(file));
String line;
while ((line = br.readLine()) != null) {
if (list.isEmpty()) {
String text = stripExtraInfo(line);
if (text != null) {
list.add(text);
}
} else {
String text = stripExtraInfo(line);
if (text != null) {
list.add(list.size() - 1, text);
}
}
}
for (String string : list) {
sb.append(string).append("\n");
}
return sb.toString();
} catch (FileNotFoundException ex) {
Logger.getLogger(LogfileUtil.class.getName()).log(Level.SEVERE, null, ex);
} finally {
try {
br.close();
} catch (IOException ex) {
Logger.getLogger(LogfileUtil.class.getName()).log(Level.SEVERE, null, ex);
}
}
long e = System.currentTimeMillis();
log.log(
Level.OFF,
"Deserialized log file, elapsed: {0} seconds",
AdministratorServlet.getElapsed(s, e));
return sb.toString();
}