Try this:
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.util.Date;
public class DetectLoggedInUser {
public static void returnUserName() {
try {
File file = new File("d:\\TestFolder\\UsersloggedIn.txt");
if (!file.exists()) {
file.createNewFile();
}
FileWriter fileWritter = new FileWriter(file, true);
BufferedWriter bufferWritter = new BufferedWriter(fileWritter);
String content = "\n UserName=" + System.getProperty("user.name")
+ " || Date and Time= " + new Date();
bufferWritter.write(content);
bufferWritter.close();
} catch (Exception ex) {
ex.printStackTrace();
}
}
public static void main(String args[]) {
returnUserName();
}
}