How Do You Read a File Line by Line in Java?

You can read a file line by line in Java using the BufferedReader class. This class provides a convenient way to read text files, one line at a time.

Here's a simple example:

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class ReadFileLineByLine {
    public static void main(String[] args) {
        try (BufferedReader reader = new BufferedReader(new FileReader("your_file.txt"))) {
            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }
        } catch (IOException e) {
            System.err.println("Error reading file: " + e.getMessage());
        }
    }
}

This code snippet demonstrates the following steps:

1. Create a BufferedReader object: This object is responsible for reading the file line by line.
2. Read each line: The readLine() method reads a single line from the file.
3. Process the line: You can then process the line as needed, such as printing it to the console, storing it in a list, or performing other operations.
4. Close the reader: It's important to close the BufferedReader object after you are finished reading the file to release the resources.

Practical Insights:

• You can use the try-with-resources statement to automatically close the BufferedReader object, ensuring that resources are released even if an exception is thrown.
• The FileReader class is used to create a file reader object that reads the file from the specified path.
• You can use the File class to create a FileReader object. For example:

    File file = new File("your_file.txt");
    FileReader reader = new FileReader(file);

• You can handle exceptions that might occur during file reading, such as FileNotFoundException or IOException.

Solutions:

• Handling empty lines: You can check if the line variable is not null and not empty before processing it.
• Skipping lines: You can use the skip(long n) method of the BufferedReader class to skip a specified number of characters.
• Reading specific lines: You can use a counter to keep track of the current line number and only process lines that meet your criteria.