Java Reference
In-Depth Information
20.5.7.
String
Character Streams
The
StringReader
reads its characters from a
String
and will never block.
It provides a single constructor that takes the string from which to read.
For example, the following program factors numbers read either from
the command line or
System.in
:
class Factor {
public static void main(String[] args) {
if (args.length == 0) {
factorNumbers(new InputStreamReader(System.in));
} else {
for (String str : args) {
StringReader in = new StringReader(str);
factorNumbers(in);
}
}
}
// ... definition of factorNumbers ...
}
If the command is invoked without parameters,
factorNumbers
parses
numbers from the standard input stream. When the command line con-
tains some arguments, a
StringReader
is created for each parameter, and
factorNumbers
is invoked on each one. The parameter to
factorNumbers
is a
stream of characters containing numbers to be parsed; it does not know
whether they come from the command line or from standard input.
StringWriter
lets you write results into a buffer that can be retrieved as
a
String
or
StringBuffer
object. It adds the following constructors and
methods:
public
StringWriter()
Creates a new
StringWriter
with a default initial buffer size.
