Another question from Khalid

[bill bozeman]

As I said in another thread, this question is a harder question but brings up some good points to remember.
4. 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" );
        osw.write(msg);
        osw.close();
    }

Select all valid answers
A. Implementation A
B. Implementation B
C. Implementation C
D. Implementation D
E. Implementation E

Try it out as a test question first, and then try compiling it to see if you are right. I got this one wrong the first time through Khalids exam.
Bill

[Sivaram Ghorakavi]

Actually I too got it wrong. I compiled and tested the answers are A & B. No setEncoding in FileWrite C is wrong, No constructor for FilterWriter(FileWriter,String) D is wrong and OutputStream is abstract.

[bill bozeman]

Close Sivaram, but A and B is what I first thought it was. You are right about C, D, and E though.
C false - there is not setEncoding() method
D false - there is no constructor for FileWriter that takes (FileWrite, String) as parameters
E false - Output stream is an abstract class so you can't say new OutputStream. There is a constructor of the OutputStreamWriter class that takes (OutputStream, String) as parameters, but it must be a class that is subclassing OutputStream.

So, which one of A and B are not correct and why.
Bill

[Balamurugan Kandasamy]

I think option B would be the right one as in option A we dont specify the encoding method and hence depending on the default setting it could vary.
MKBala...

[rajani peddi]

Bill,
A is not correct because it can't mention the encoding. only B can specify the encoding in its constructor. hence B is correct.
Correct me if i am wrong
rajani

[Balamurugan Kandasamy]

Think the above post is not structurally well formed ::
Option B is right.
Option A need not be right as the default encoding may vary depending on system settings.
MKBala...

[bill bozeman]

Your right, B is the only correct answer. The default encoding method is the method that is set on the local machine, so the only way to guarantee the encoding of UTF8 is to assign it with OutputStreamWriter constructor that looks like this:
OutputStreamWriter(OutputStream out, String enc)
First time I did the exam, I thought A was correct also, and when you compile it, it looks correct, but B is the only option that is guaranteed to be correct.
Bill
[This message has been edited by bill bozeman (edited December 20, 2000).]

[Panagiotis Varlagas]

Actually the question is not precise enough. It could be rephrased as follows:
"Which method implementations will write the given string to a file named "file", using UTF8 encoding, regardless of the default character encoding of the local machine?