BufferedReader to skip first line

Question

I am using the following bufferedreader to read the lines of a file,

BufferedReader reader = new BufferedReader(new FileReader(somepath));
while ((line1 = reader.readLine()) != null) 
{
    //some code
}

Now, I want to skip reading the first line of the file and I don't want to use a counter line int lineno to keep a count of the lines.

How to do this?

Ornament

Why don't you readLine and ignore it? – Shipwreck

Just call reader.readLine() before the loop. – Hoenack

possible duplicate of Skipping over the first line when reading a textfile – Counterpunch

@AndrewLogvinov Thank you! I've used your method and seems to be the most efficient way possible, please post it as an answer. – Ornament

Answer 1

You can try this

 BufferedReader reader = new BufferedReader(new FileReader(somepath));
 reader.readLine(); // this will read the first line
 String line1=null;
 while ((line1 = reader.readLine()) != null){ //loop will run from 2nd line
        //some code
 }

Somersault

Simple. How come I didn't thought of that? :D – Quantic

I feel so dumb now :D – Shannan

Answer 2

You can use the Stream skip() function, like this:

BufferedReader reader = new BufferedReader(new FileReader(somepath));   
Stream<String> lines = reader.lines().skip(1);

lines.forEachOrdered(line -> {

...
});

Aspergillus

While this code may solve the question, including an explanation of how and why this solves the problem would really help to improve the quality of your post, and probably result in more up-votes. Remember that you are answering the question for readers in the future, not just the person asking now. Please edit your answer to add explanations and give an indication of what limitations and assumptions apply. – Leyte

this one is perfect. – Suetonius

worth mention that this solution will not trigger errors on code analysis software like SonaQube, while the chosen one will throw an error a bug error – Broadcloth

@Broadcloth the chosen error one can be resolved with try (BufferedReader reader = new BufferedReader(new FileReader(somepath))) { ..... code }, not big deal – Allbee

Answer 3

File file = new File("path to file");
FileInputStream fis = new FileInputStream(file);
BufferedReader br = new BufferedReader(new InputStreamReader(fis));
String line = null;
int count = 0;
while((line = br.readLine()) != null) { // read through file line by line
    if(count != 0) { // count == 0 means the first line
        System.out.println("That's not the first line");
    }
    count++; // count increments as you read lines
}
br.close(); // do not forget to close the resources

Taligrade

Adding comments on how your code works would help users to better understand your code. – Kiowa

Hope my code is more clear now with the comments. Thanks for the warning ;) – Taligrade

Answer 4

Use a linenumberreader instead.

LineNumberReader reader = new LineNumberReader(new InputStreamReader(file.getInputStream()));
            String line1;
            while ((line1 = reader.readLine()) != null) 
            {
                if(reader.getLineNumber()==1){
                    continue;
                }
                System.out.println(line1);
            }

Eraser

This is quite possibly the most inefficient and over-complicated way to solve this problem. – Counterpunch

@BrianRoach Why do you think linenumberreader is over complicated? – Eraser

Because A) it's not necessary and B) you're doing a unnecessary comparison on every read. – Counterpunch

A) It gives you control to skip any line you wish. Not limited to the first line. B) I didn't see any performance issue related remark in the question. I hope the user will definitely customize the solution and not copy paste it. In fact even the InputstreamReader is not required here, fileReader will do. Are we being too opinionated here? – Eraser

My personal opinion is why build the space shuttle when all you need is a biplane. You want to skip the first line in a file. You have a BufferedReader. Call readLine() prior to the loop. Done. – Counterpunch

Answer 5

You can create a counter that contains the value of the starting line:

private final static START_LINE = 1;

BufferedReader reader = new BufferedReader(new FileReader(somepath));
int counter=START_LINE;

while ((line1 = reader.readLine()) != null) {
  if(counter>START_LINE){
     //your code here
  }
  counter++;
}

Convex

Answer 6

You can do it like this:

BufferedReader buf = new BufferedReader(new FileReader(fileName));
            String line = null;
            String[] wordsArray;
            boolean skipFirstLine = true;


while(true){
                line = buf.readLine();
                if ( skipFirstLine){ // skip data header
                    skipFirstLine = false; continue;
                }
                if(line == null){  
                    break; 
                }else{
                    wordsArray = line.split("\t");
}
buf.close();

Cutler