/* * Copyright 2005-2010 Ignis Software Tools Ltd. All rights reserved. */ package jsystem.treeui.client; import java.io.File; import java.io.FileInputStream; import java.nio.CharBuffer; import java.nio.MappedByteBuffer; import java.nio.channels.FileChannel; import java.nio.charset.Charset; import java.nio.charset.CharsetDecoder; import java.util.regex.Matcher; import java.util.regex.Pattern; import java.util.regex.PatternSyntaxException; /** * This utility class provides a subset of the grep functionality. * * @author Guy Chen */ public class GrepLog { // Charset and decoder for ISO-8859-15 private static Charset charset = Charset.forName("ISO-8859-15"); private static CharsetDecoder decoder = charset.newDecoder(); // Pattern used to parse lines private static Pattern linePattern = Pattern.compile(".*\r?\n"); // The input pattern that we're looking for private static Pattern pattern; // Compile the pattern from the command line // private static void compile(String pat) { try { pattern = Pattern.compile(pat); } catch (PatternSyntaxException x) { System.err.println(x.getMessage()); System.exit(1); } } public boolean grep(File file, String strToSearch) { compile(strToSearch); boolean bFound = false; // Open the file and then get a channel from the stream try { FileInputStream fis = new FileInputStream(file); FileChannel fc = fis.getChannel(); // Get the file's size and then map it into memory int sz = (int) fc.size(); MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, sz); // Decode the file into a char buffer CharBuffer cb = decoder.decode(bb); // Perform the search Matcher lm = linePattern.matcher(cb); // Line matcher Matcher pm = null; // Pattern matcher int lines = 0; while (lm.find()) { lines++; CharSequence cs = lm.group(); // The current line if (pm == null) pm = pattern.matcher(cs); else pm.reset(cs); if (pm.find()) { System.out.print(file + ":" + lines + ":" + cs); bFound = true; } if (lm.end() == cb.limit()) break; } // Close the channel and the stream fc.close(); } catch (Exception e) { System.out.println(e.toString()); return bFound; } return bFound; } }