Using a Regular Expression to Filter Lines from a Reader
A common use of regular expressions is to find all lines that match a
pattern, similar to the grep Unix command. This example reads lines
using a BufferedReader and tests each line for a match.
try {
// Create the reader
String filename = "infile.txt";
String patternStr = "pattern";
BufferedReader rd = new BufferedReader(new FileReader(filename));
// Create the pattern
Pattern pattern = Pattern.compile(patternStr);
Matcher matcher = pattern.matcher("");
// Retrieve all lines that match pattern
String line = null;
while ((line = rd.readLine()) != null) {
matcher.reset(line);
if (matcher.find()) {
// line matches the pattern
}
}
} catch (IOException e) {
}
Post a comment