Read a line containing only ASCII characters from the input
stream. A line is terminated by a CR or NL or CR-NL sequence.
A common error is a CR-CR-NL sequence, which will also terminate
a line.
The line terminator is not returned as part of the returned
String. Returns null if no data is available.
This class is similar to the deprecated
DataInputStream.readLine()
InputStream in = this.in;
char[] buf = lineBuffer;
if (buf == null)
buf = lineBuffer = new char[128];
int c1;
int room = buf.length;
int offset = 0;
while ((c1 = in.read()) != -1) {
if (c1 == '\n") // Got NL, outa here.
break;
else if (c1 == '\r") {
// Got CR, is the next char NL ?
int c2 = in.read();
if (c2 == '\r") // discard extraneous CR
c2 = in.read();
if (c2 != '\n") {
// If not NL, push it back
if (!(in instanceof PushbackInputStream))
in = this.in = new PushbackInputStream(in);
((PushbackInputStream)in).unread(c2);
}
break; // outa here.
}
// Not CR, NL or CR-NL ...
// .. Insert the byte into our byte buffer
if (--room < 0) { // No room, need to grow.
buf = new char[offset + 128];
room = buf.length - offset - 1;
System.arraycopy(lineBuffer, 0, buf, 0, offset);
lineBuffer = buf;
}
buf[offset++] = (char)c1;
}
if ((c1 == -1) && (offset == 0))
return null;
return String.copyValueOf(buf, 0, offset);
