java.io with UTF8

[Anonymous]

I'm stumpted... Which one is correct and why?
Which method implementations will write the given string to a file named "file", using UTF8 encoding?
IMPLEMENTATION A:
public void write(String msg) throws IOException {
FileWriter fw = new FileWriter(new File("file"));
fw.write(msg);
fw.close();
}
IMPLEMENTATION B:
public void write(String msg) throws IOException {
OutputStreamWriter osw =
new OutputStreamWriter(new FileOutputStream("file"), "UTF8");
osw.write(msg);
osw.close();
}
IMPLEMENTATION C:
public void write(String msg) throws IOException {
FileWriter fw = new FileWriter(new File("file"));
fw.setEncoding("UTF8");
fw.write(msg);
fw.close();
}
IMPLEMENTATION D:
public void write(String msg) throws IOException {
FilterWriter fw = FilterWriter(new FileWriter("file"), "UTF8");
fw.write(msg);
fw.close();
}
IMPLEMENTATION E:
public void write(String msg) throws IOException {
OutputStreamWriter osw = new OutputStreamWriter(
new OutputStream(new File("file")), "UTF8"
}

[Herbert Maosa]

Monty,
I think only OutputStreamWriter and InputStreamReader have constructors that allow you to specify the encoding.Its subclasses, like FileReader and FileWriter DO NOT and when you use them, always the default encoding of your system is used.So to specify an encoding, you need to create your own reader or writer by using the OutputStreamWriter or InputStreamReader. With this in mind, then in your question we can immediately rule out A,C and D. That leaves us with B and E. But if you look closely in implementation E you see that a File onject is passed to an OutputStream constructor and apparently OutputStream does not have a constructor that takes a File object as its argument.So that one is not correct.Therefore the only correct answer is B IMNSHO.
Others may need to verify this.
Herbert

[Jim Yingst]

Looks right, Herbert. I suppose A would work if you're on a system where the system default is already UTF8, but that's generally not going to be the case. Certainly for purposes of the exam we should assume it isn't the case.

[Jimmy Blakely]

E is incorrect because OutputStream is an abstract class, and therefore cannot be initialized.

[Jane Griscti]

monty6,
Please read the JavaRanch Name Policy and re-register using a name that complies with the rules.
Thanks for your cooperation.
------------------
Jane Griscti
Sun Certified Programmer for the Java� 2 Platform