InputStreamReader don't limit returned length

InputStreamReader don't limit returned length

I am working on learning Java and am going through the examples on the
Android website. I am getting remote contents of an XML file. I am able to
get the contents of the file, but then I need to convert the InputStream
into a String.
public String readIt(InputStream stream, int len) throws IOException,
UnsupportedEncodingException {
InputStreamReader reader = null;
reader = new InputStreamReader(stream, "UTF-8");
char[] buffer = new char[len];
reader.read(buffer);
return new String(buffer);
}
The issue I am having is I don't want the string to be limited by the len
var. But, I don't know java well enough to know how to change this.
How can I create the char without a length?