Question

I have a program that I’m writing where I am using another company’s library to download some reports from their website. I want to parse these reports before I write them to a file, because if they match certain criteria, I want to disregard them.

Problem is, their method, called download() returns a java.io.Reader. The only method available to me is

int read(char[] cbuf);

Printing this returned array out gives me meaningless characters. I want to be able to identify what character set I’m working with or convert it to a byte array but I can’t figure out how to do it. I’ve tried

//retrievedFile is my Reader object
char[] cbuf = new char[2048];
int numChars = retrievedFile.read(cbuf);
//I've tried other character sets, too
new String(cbuf).getBytes("UTF-8");

and I’m afraid to downcast to a more useful reader because I can’t know for sure if it will work or not. Any suggestions?

EDIT

When I say it prints out “meaningless characters”, I don’t mean that it looks like the example given by Jon Skeet. It’s really hard to describe because I’m not at my machine right now, but I think it’s an encoding issue. The characters seem to have indentations and structure similar to the look of the reports. I’ll try these suggestions as soon as I get back on Tuesday (I’m only an intern, so I haven’t bothered with setting up a remote account or anything).

Answer 1

Try this:

BufferedReader in = new BufferedReader(retrievedFile);
String line = null;
StringBuilder rslt = new StringBuilder();
while ((line = in.readLine()) != null) {
    rslt.append(line);
}
System.out.println(rslt.toString());

Don’t typecast the Reader to any class because you don’t know the real type of it.
Instead, use BufferedReader and pass Reader into it. And BufferedReader take any subclass of java.io.Reader as the argument so it is save to use it.