Writing to a file using BufferedOutputStream in Java

22 Sep 2023

FileWriting

One common task in Java programming is writing data to a file. This can be done efficiently using the BufferedOutputStream class, which provides buffering capabilities to improve performance.

Steps to write to a file using BufferedOutputStream

Create an instance of FileOutputStream: First, create an instance of the FileOutputStream class, which represents the output file. This class provides a way to write bytes to a file.
```
FileOutputStream fileOutputStream = new FileOutputStream("output.txt");
```
Create an instance of BufferedOutputStream: Next, create an instance of the BufferedOutputStream class, passing the FileOutputStream object as a parameter. This class serves as a buffer for the FileOutputStream, reducing the number of disk writes.
```
BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(fileOutputStream);
```

Write data to the file: Now, you can write data to the file using the write() method of the BufferedOutputStream class. Pass the byte array or a single byte as a parameter to this method.

byte[] data = "Hello, World!".getBytes();
bufferedOutputStream.write(data); // write byte array to the file
bufferedOutputStream.write('\n');  // write a newline character
bufferedOutputStream.write('A');   // write a single byte

Flush and close the streams: Finally, to make sure all the data is written to the file, you should flush the BufferedOutputStream and close both the BufferedOutputStream and FileOutputStream.
```
bufferedOutputStream.flush();
bufferedOutputStream.close();
fileOutputStream.close();
```

Example: Writing to a File using BufferedOutputStream

Here’s a complete example that demonstrates how to write data to a file using BufferedOutputStream in Java.

import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class FileWritingExample {
    public static void main(String[] args) {
        try {
            FileOutputStream fileOutputStream = new FileOutputStream("output.txt");
            BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(fileOutputStream);

            String text = "Hello, World!";
            byte[] data = text.getBytes();

            bufferedOutputStream.write(data);
            bufferedOutputStream.write('\n');
            bufferedOutputStream.write('A');

            bufferedOutputStream.flush();
            bufferedOutputStream.close();
            fileOutputStream.close();

            System.out.println("Data written to file successfully.");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

In this example, we write “Hello, World!\nA” to the file “output.txt”.

Conclusion

Using the BufferedOutputStream in Java allows you to write data efficiently to a file by leveraging buffering. This can have a significant impact on performance, especially when dealing with large amounts of data. By following the steps mentioned above and using the provided example code, you can easily write to a file using BufferedOutputStream in your Java programs.

#Java #FileWriting