Java Reference
In-Depth Information
new
new
URL
(
url
).
openStream
()));
// Read the URL looking for the rank information, as
// a single long string, so can match RE across multi-lines.
final
final
String input
=
readerToString
(
is
);
// If found, append to sales data file.
Matcher m
=
r
.
matcher
(
input
);
iif
(
m
.
find
()) {
// Paren 1 is the digits (and maybe ','s) that matched; remove comma
return
return
Integer
.
parseInt
(
m
.
group
(
1
).
replace
(
","
,
""
));
}
else
else
{
throw
throw new
new
RuntimeException
(
"Pattern not matched in `"
+
url
+
"'!"
);
}
}
private
private static
static
String
readerToString
(
BufferedReader is
)
throws
throws
IOException
{
StringBuilder sb
=
new
new
StringBuilder
();
String line
;
while
while
((
line
=
is
.
readLine
()) !=
null
null
) {
sb
.
append
(
line
);
}
return
return
sb
.
toString
();
}
}
Program: Full Grep
Now that we've seen how the regular expressions package works, it's time to write
JGrep
, a
full-blown version of the line-matching program with option parsing.
Table 4-2
lists some
typical command-line options that a Unix implementation of
grep
might include.
