Java Reference
In-Depth Information
System.in
is an object of type
InputStream
;
System.out
and
System.err
are objects
of type
PrintStream
. These are byte streams, even though they are typically used to read
and write characters from and to the console. The reason they are byte and not character
streams is that the predefined streams were part of the original specification for Java, which
did not include the character streams. As you will see, it is possible to wrap these within
character-based streams if desired.
Using the Byte Streams
We will begin our examination of Java's I/O with the byte streams. As explained, at the top
of the byte stream hierarchy are the
InputStream
and
OutputStream
classes.
Table 10-3
shows the methods in
InputStream
, and
Table 10-4
shows the methods in
OutputStream
.
In general, the methods in
InputStream
and
OutputStream
can throw an
IOException
on error. The methods defined by these two abstract classes are available to all of their sub-
classes. Thus, they form a minimal set of I/O functions that all byte streams will have.
Table 10-3
The Methods Defined by
InputStream
