import java.io.*; 

public class ForceTimer { 
    public static void main(String[] args) throws Exception { 
        File tempFile = File.createTempFile("tmp", null); 
        RandomAccessFile randomAccessFile = new RandomAccessFile(tempFile, "rw"); 
        long start = System.currentTimeMillis(); 
        for (int i = 0; i < 10000; i++) { 
            String line = i + "\n"; 
            randomAccessFile.write(line.getBytes()); 
            randomAccessFile.getChannel().force(false); 
        } 
        long end = System.currentTimeMillis(); 
        System.out.println("Elapsed time " + (end - start) + "ms"); 
        randomAccessFile.close(); 
        tempFile.delete(); 
    } 
}