File file = new File("path and file name you want to save");

FileOutputStream fos = new FileOutputStream(file); fos.write(//byte you want to write); fos.close();

或者用FileWriter如果写入的是char流，方便

what i will do is ask the user to specify a path which they want to create the file. The program can be written in a few ways, i.e. using different class, they are gernally three of them, FileWriter, BufferedWriter and PrintWriter, in here i will use PrintWriter, because this is the easiest way.

public class Write{

public static void main(String[] args) throws IOException{

//to use the PrintWriter class which must pass in a FileWriter object as parameter

PrinteWriter pr = new PrintWriter(new FileWriter(agrs[0])); /*args[0] is the first file name specified by the user in the command line, if the file name doesnt exist, it will create a new one*/

pr.println("Whatever you wanna type.");

pr.print("Pretty much the same as using System.out.");

pr.close(); // this is very important

}

}