A text file in Java can be read line by line with the help of BufferedReader class in Java.

The simple code is:

FileInputStream fstream = new FileInputStream("textfile.txt");
DataInputStream in = new DataInputStream(fstream);
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String strLine;
while ((strLine = br.readLine()) != null)   {
    System.out.println (strLine);
}

Read the details at How to read file line by line in Java?

What is the benefits of reading a file line by line in Java?

Now let's discuss the benefits of reading a file line by line.

Actually you can read a file at once in memory, but there is the limit of the memory. So, you can't read the big file in memory at once due to memory constraints.

So, reading a file line by line is the best option and it takes less memory and the performance of the application is also very good.

So, if there is any requirement of reading a text file in your project then you should always write the code to read a file line by line.

Thanks

Why I can't read a big text file in memory?

You can't read the whole content of big file in memory at one go due to memory constraint of the hardware and operating system.

Reading the whole file in memory at one go is also requires more processing power and it may slow down the performance of your application.

Thanks

Very good Explanation.Thanks for your valuable sharing.

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