/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
/* $Id: Grep.java 152682 2005-02-08 18:13:39Z gregor $ */
package org.apache.lenya.search;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.nio.CharBuffer;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.avalon.framework.logger.ConsoleLogger;
import org.apache.avalon.framework.logger.Logger;
/**
* Utility class to provide a subset of the grep functionality.
*/
public class Grep {
private static Charset charset = Charset.forName("UTF-8");
private static CharsetDecoder decoder = charset.newDecoder();
/**
* Check if the given file contains the pattern
* @param file the file which is to be searched for the pattern
* @param pattern the pattern that is being searched.
* @return true if the file contains the string, false otherwise.
* @throws IOException
*/
public static boolean containsPattern(File file, Pattern pattern) throws IOException {
Logger log = new ConsoleLogger();
FileChannel fc = null;
// Open the file and then get a channel from the stream
FileInputStream fis = null;
boolean result = false;
try {
fis = new FileInputStream(file);
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 pm = pattern.matcher(cb); // Pattern matcher
result = pm.find();
} catch (FileNotFoundException e) {
log.error("File not found: " +e.toString());
} catch (CharacterCodingException e) {
log.error("Problem with encoding: " +e.toString());
} catch (IOException e) {
log.error("IO Exception: " +e.toString());
} finally {
// Close the channel and the stream
if (fc != null)
fc.close();
if (fis != null)
fis.close();
}
return result;
}
/**
* Find all occurences of pattern in a file.
* @param file the file to search for occurences of pattern
* @param pattern the pattern to search for
* @param group which group in the pattern to return
* @return an <code>array</code> of occurences of pattern
* (i.e. the groupth group of the match)
* @throws IOException if the file could not be read.
*/
public static String[] findPattern(File file, Pattern pattern, int group) throws IOException {
Logger log = new ConsoleLogger();
ArrayList occurences = new ArrayList();
FileInputStream fis = null;
FileChannel fc = null;
try {
// Open the file and then get a channel from the stream
fis = new FileInputStream(file);
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 pm = pattern.matcher(cb); // Pattern matcher
while (pm.find()) {
occurences.add(pm.group(group));
}
} catch (FileNotFoundException e) {
log.error("file not found " +e.toString());
} catch (CharacterCodingException e) {
log.error("encoding problem " +e.toString());
} catch (IOException e) {
log.error("IO exception" +e.toString());
} finally {
// Close the channel and the stream
if (fc != null)
fc.close();
if (fis != null)
fis.close();
}
return (String[])occurences.toArray(new String[occurences.size()]);
}
/**
* Find all files below the given file which contain the given pattern.
* @param file the file where to start the search for the pattern.
* @param pattern the pattern to search for.
* @return an array of files which contain the pattern
* @throws IOException if any of the files could not be opened.
*/
private static List find_internal(File file, Pattern pattern) throws IOException {
ArrayList fileList = new ArrayList();
if (file.isDirectory()) {
String[] children = file.list();
for (int i = 0; i < children.length; i++) {
fileList.addAll(
find_internal(
new File(file.getAbsolutePath(), children[i]),
pattern));
}
} else if (file.isFile() && containsPattern(file, pattern)) {
fileList.add(file);
}
return fileList;
}
/**
* Find all files below the given file which contain the given search string.
*
* @param file the where to start the search
* @param searchString the string to search for.
*
* @return an array of files which contain the search string.
*
* @throws IOException if any of the files could not be opened.
*/
public static File[] find(File file, String searchString) throws IOException {
Pattern pattern = Pattern.compile(searchString);
List fileList = find_internal(file, pattern);
return (File[])fileList.toArray(new File[fileList.size()]);
}
}