In Java, we can use OutputStreamWriter to write data to a file. It converts the characters into bytes and writes them to the underlying output stream. Here’s an example that demonstrates how to write data to a file using OutputStreamWriter.

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.nio.charset.StandardCharsets;

public class FileWriterExample {
    public static void main(String[] args) {
        String filename = "output.txt";
        String data = "Hello, world!";

        // Create FileOutputStream
        try (FileOutputStream fos = new FileOutputStream(filename);
             OutputStreamWriter writer = new OutputStreamWriter(fos, StandardCharsets.UTF_8)) {
            
            // Write data to the file
            writer.write(data);

            // Flush and close the writer
            writer.flush();
            writer.close();

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

In the above example, we first define the filename and the data that we want to write to the file. We then create a FileOutputStream by providing the filename.

Next, we create an OutputStreamWriter by passing the FileOutputStream and the character encoding (in this case, StandardCharsets.UTF_8). This ensures that the characters are correctly converted to bytes using the specified encoding.

We then write the data to the file using the write method of the OutputStreamWriter. After writing, we flush and close the writer to ensure that all the data is written and the resources are properly released.

Finally, we print a success message to indicate that the data has been written to the file successfully.

Make sure to handle any IOException that may occur during the file writing process.

With this example, you now know how to use OutputStreamWriter to write data to a file in Java. Happy coding!