How to efficiently flush and write large amounts of data to a file using BufferedWriter in Java?

I'm working on a Java project where I need to write a large number of lines to a file. I know BufferedWriter can improve performance compared to writing character by character, but I am unsure about the best practices for flushing the buffer and ensuring all data is written correctly.

Here’s my current code:

import java.io.BufferedWriter; import java.io.FileWriter; import java.io.IOException; public class FileWriteExample { public static void main(String[] args) { try (BufferedWriter writer = new BufferedWriter(new FileWriter("output.txt"))) { for (int i = 0; i < 100000; i++) { writer.write("Line " + i + "\n"); } // Do I need to call writer.flush() here explicitly? } catch (IOException e) { e.printStackTrace(); } } }

Questions:

Is it necessary to call writer.flush() explicitly before closing the BufferedWriter?

Are there performance differences between calling flush() periodically inside the loop vs relying on try-with-resources?

What are the recommended best practices for writing large files efficiently in Java?