如何检查文件中的空行，然后在Java中忽略它们？

Question

I've seen similar questions asked about how to find a blank line. I know how to find a blank line, but the sheer nature of finding it retrieves it and screws up the rest of your code.

Consider the following while loop:

while(file.hasNextLine()){
    if(file.nextLine.equals("")){
        continue;
    }
    String[] words = file.nextLine().split(" ");
    for(int i = 0; i < words.length; i++){
        System.out.print(words[i]);
    }
}

The idea here is to say, if there is a blank line, skip this iteration and move to the next line only extracting words. But just checking to see if the line is blank retrieves the next line (blank or not) and then retrieves the FOLLOWING line and stores it in words.

What is the proper way to find blank lines without actually retrieving 'nextLine' to do so?

Answer 1

Call file.nextLine() , but store it in a variable before checking it for emptiness. That way you'll only call it once per iteration.

while(file.hasNextLine()){
    final String line = file.nextLine();
    if(line.isEmpty()){
        continue;
    }
    String[] words = line.split(" ");
    for(int i = 0; i < words.length; i++){
        System.out.print(words[i]);
    }
}