selectorutils.java

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/*
 *  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.
 *
 */

package org.apache.tools.ant.types.selectors;

import java.io.File;
import java.util.StringTokenizer;
import java.util.Vector;

import org.apache.tools.ant.types.Resource;
import org.apache.tools.ant.util.FileUtils;
import org.apache.tools.ant.types.resources.FileResource;

/**
 * <p>This is a utility class used by selectors and DirectoryScanner. The
 * functionality more properly belongs just to selectors, but unfortunately
 * DirectoryScanner exposed these as protected methods. Thus we have to
 * support any subclasses of DirectoryScanner that may access these methods.
 * </p>
 * <p>This is a Singleton.</p>
 *
 * @since 1.5
 */
public final class SelectorUtils {

    private static SelectorUtils instance = new SelectorUtils();
    private static final FileUtils FILE_UTILS = FileUtils.getFileUtils();

    /**
     * Private Constructor
     */
    private SelectorUtils() {
    }

    /**
     * Retrieves the instance of the Singleton.
     * @return singleton instance
     */
    public static SelectorUtils getInstance() {
        return instance;
    }

    /**
     * Tests whether or not a given path matches the start of a given
     * pattern up to the first "**".
     * <p>
     * This is not a general purpose test and should only be used if you
     * can live with false positives. For example, <code>pattern=**\a</code>
     * and <code>str=b</code> will yield <code>true</code>.
     *
     * @param pattern The pattern to match against. Must not be
     *                <code>null</code>.
     * @param str     The path to match, as a String. Must not be
     *                <code>null</code>.
     *
     * @return whether or not a given path matches the start of a given
     * pattern up to the first "**".
     */
    public static boolean matchPatternStart(String pattern, String str) {
        return matchPatternStart(pattern, str, true);
    }

    /**
     * Tests whether or not a given path matches the start of a given
     * pattern up to the first "**".
     * <p>
     * This is not a general purpose test and should only be used if you
     * can live with false positives. For example, <code>pattern=**\a</code>
     * and <code>str=b</code> will yield <code>true</code>.
     *
     * @param pattern The pattern to match against. Must not be
     *                <code>null</code>.
     * @param str     The path to match, as a String. Must not be
     *                <code>null</code>.
     * @param isCaseSensitive Whether or not matching should be performed
     *                        case sensitively.
     *
     * @return whether or not a given path matches the start of a given
     * pattern up to the first "**".
     */
    public static boolean matchPatternStart(String pattern, String str,
                                            boolean isCaseSensitive) {
        // When str starts with a File.separator, pattern has to start with a
        // File.separator.
        // When pattern starts with a File.separator, str has to start with a
        // File.separator.
        if (str.startsWith(File.separator)
                != pattern.startsWith(File.separator)) {
            return false;
        }

        String[] patDirs = tokenizePathAsArray(pattern);
        String[] strDirs = tokenizePathAsArray(str);

        int patIdxStart = 0;
        int patIdxEnd = patDirs.length - 1;
        int strIdxStart = 0;
        int strIdxEnd = strDirs.length - 1;

        // up to first '**'
        while (patIdxStart <= patIdxEnd && strIdxStart <= strIdxEnd) {
            String patDir = patDirs[patIdxStart];
            if (patDir.equals("**")) {
                break;
            }
            if (!match(patDir, strDirs[strIdxStart], isCaseSensitive)) {
                return false;
            }
            patIdxStart++;
            strIdxStart++;
        }

        // CheckStyle:SimplifyBooleanReturnCheck OFF
        // Check turned off as the code needs the comments for the various
        // code paths.
        if (strIdxStart > strIdxEnd) {
            // String is exhausted
            return true;
        } else if (patIdxStart > patIdxEnd) {
            // String not exhausted, but pattern is. Failure.
            return false;
        } else {
            // pattern now holds ** while string is not exhausted
            // this will generate false positives but we can live with that.
            return true;
        }
    }

    /**
     * Tests whether or not a given path matches a given pattern.
     *
     * @param pattern The pattern to match against. Must not be
     *                <code>null</code>.
     * @param str     The path to match, as a String. Must not be
     *                <code>null</code>.
     *
     * @return <code>true</code> if the pattern matches against the string,
     *         or <code>false</code> otherwise.
     */
    public static boolean matchPath(String pattern, String str) {
        return matchPath(pattern, str, true);
    }

    /**
     * Tests whether or not a given path matches a given pattern.
     *
     * @param pattern The pattern to match against. Must not be
     *                <code>null</code>.
     * @param str     The path to match, as a String. Must not be
     *                <code>null</code>.
     * @param isCaseSensitive Whether or not matching should be performed
     *                        case sensitively.
     *
     * @return <code>true</code> if the pattern matches against the string,
     *         or <code>false</code> otherwise.
     */
    public static boolean matchPath(String pattern, String str,
                                    boolean isCaseSensitive) {
        String[] patDirs = tokenizePathAsArray(pattern);
        String[] strDirs = tokenizePathAsArray(str);

        int patIdxStart = 0;
        int patIdxEnd = patDirs.length - 1;
        int strIdxStart = 0;
        int strIdxEnd = strDirs.length - 1;

        // up to first '**'
        while (patIdxStart <= patIdxEnd && strIdxStart <= strIdxEnd) {
            String patDir = patDirs[patIdxStart];
            if (patDir.equals("**")) {
                break;
            }
            if (!match(patDir, strDirs[strIdxStart], isCaseSensitive)) {
                patDirs = null;
                strDirs = null;
                return false;
            }
            patIdxStart++;
            strIdxStart++;
        }
        if (strIdxStart > strIdxEnd) {
            // String is exhausted
            for (int i = patIdxStart; i <= patIdxEnd; i++) {
                if (!patDirs[i].equals("**")) {
                    patDirs = null;
                    strDirs = null;
                    return false;
                }
            }
            return true;
        } else {
            if (patIdxStart > patIdxEnd) {
                // String not exhausted, but pattern is. Failure.
                patDirs = null;
                strDirs = null;
                return false;
            }
        }

        // up to last '**'
        while (patIdxStart <= patIdxEnd && strIdxStart <= strIdxEnd) {
            String patDir = patDirs[patIdxEnd];
            if (patDir.equals("**")) {
                break;
            }
            if (!match(patDir, strDirs[strIdxEnd], isCaseSensitive)) {
                patDirs = null;
                strDirs = null;
                return false;
            }
            patIdxEnd--;
            strIdxEnd--;
        }
        if (strIdxStart > strIdxEnd) {
            // String is exhausted
            for (int i = patIdxStart; i <= patIdxEnd; i++) {
                if (!patDirs[i].equals("**")) {
                    patDirs = null;
                    strDirs = null;
                    return false;
                }
            }
            return true;
        }

        while (patIdxStart != patIdxEnd && strIdxStart <= strIdxEnd) {
            int patIdxTmp = -1;
            for (int i = patIdxStart + 1; i <= patIdxEnd; i++) {
                if (patDirs[i].equals("**")) {
                    patIdxTmp = i;
                    break;
                }
            }
            if (patIdxTmp == patIdxStart + 1) {
                // '**/**' situation, so skip one
                patIdxStart++;
                continue;
            }
            // Find the pattern between padIdxStart & padIdxTmp in str between
            // strIdxStart & strIdxEnd
            int patLength = (patIdxTmp - patIdxStart - 1);
            int strLength = (strIdxEnd - strIdxStart + 1);
            int foundIdx = -1;
            strLoop:
                        for (int i = 0; i <= strLength - patLength; i++) {
                            for (int j = 0; j < patLength; j++) {
                                String subPat = patDirs[patIdxStart + j + 1];
                                String subStr = strDirs[strIdxStart + i + j];
                                if (!match(subPat, subStr, isCaseSensitive)) {
                                    continue strLoop;
                                }
                            }

                            foundIdx = strIdxStart + i;
                            break;
                        }

            if (foundIdx == -1) {
                patDirs = null;
                strDirs = null;
                return false;
            }

            patIdxStart = patIdxTmp;
            strIdxStart = foundIdx + patLength;
        }

        for (int i = patIdxStart; i <= patIdxEnd; i++) {
            if (!patDirs[i].equals("**")) {
                patDirs = null;
                strDirs = null;
                return false;
            }
        }

        return true;
    }

    /**
     * Tests whether or not a string matches against a pattern.
     * The pattern may contain two special characters:<br>
     * '*' means zero or more characters<br>
     * '?' means one and only one character
     *
     * @param pattern The pattern to match against.
     *                Must not be <code>null</code>.
     * @param str     The string which must be matched against the pattern.
     *                Must not be <code>null</code>.
     *
     * @return <code>true</code> if the string matches against the pattern,
     *         or <code>false</code> otherwise.
     */
    public static boolean match(String pattern, String str) {
        return match(pattern, str, true);
    }

    /**
     * Tests whether or not a string matches against a pattern.
     * The pattern may contain two special characters:<br>
     * '*' means zero or more characters<br>
     * '?' means one and only one character
     *
     * @param pattern The pattern to match against.
     *                Must not be <code>null</code>.
     * @param str     The string which must be matched against the pattern.
     *                Must not be <code>null</code>.
     * @param isCaseSensitive Whether or not matching should be performed
     *                        case sensitively.
     *
     *
     * @return <code>true</code> if the string matches against the pattern,
     *         or <code>false</code> otherwise.
     */
    public static boolean match(String pattern, String str,
                                boolean isCaseSensitive) {
        char[] patArr = pattern.toCharArray();
        char[] strArr = str.toCharArray();
        int patIdxStart = 0;
        int patIdxEnd = patArr.length - 1;
        int strIdxStart = 0;
        int strIdxEnd = strArr.length - 1;
        char ch;

        boolean containsStar = false;
        for (int i = 0; i < patArr.length; i++) {
            if (patArr[i] == '*') {
                containsStar = true;
                break;
            }
        }