简体   繁体   中英

Java: Reading the Trailing New Line from a Text File

How can you get the contents of a text file while preserving whether or not it has a newline at the end of the file? Using this technique, it is impossible to tell if the file ends in a newline:

BufferedReader reader = new BufferedReader(new FileReader(fromFile));
StringBuilder contents = new StringBuilder();

String line = null;
while ((line=reader.readLine()) != null) {
  contents.append(line);
  contents.append("\n");
}

Don't use readLine(); transfer the contents one character at a time using the read() method. If you use it on a BufferedReader, this will have the same performance, although unlike your code above it will not "normalize" Windows-style CR/LF line breaks.

You can read the whole file content using one of the techniques listed here

My favorite is this one:

public static long copyLarge(InputStream input, OutputStream output)
       throws IOException {
   byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
   long count = 0;
   int n = 0;
   while ((n = input.read(buffer))>=0) {
       output.write(buffer, 0, n);
       count += n;
   }
   return count;

}

The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM