![]() |
The Java Developers Almanac 1.4Order this book from Amazon. |
e441. Using a Regular Expression to Filter Lines from a ReaderA common use of regular expressions is to find all lines that match a pattern, similar to thegrep 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) { }
e443. Matching Line Boundaries in a Regular Expression e444. Matching Across Line Boundaries in a Regular Expression e445. Reading Lines from a String Using a Regular Expression e446. Removing Line Termination Characters from a String
© 2002 Addison-Wesley. |