/*
 *  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
 *
 *      https://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;

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.

This is a Singleton.
Since:
1.5/**
 * <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 {

    
The pattern that matches an arbitrary number of directories.
Since:
Ant 1.8.0/**
     * The pattern that matches an arbitrary number of directories.
     * @since Ant 1.8.0
     */
    public static final String DEEP_TREE_MATCH = "**";

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

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

    
Retrieves the instance of the Singleton.
Returns:
singleton instance/**
     * 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 "**".

This is not a general purpose test and should only be used if you
can live with false positives. For example, pattern=**\a
and str=b will yield true.
Params:
pattern – The pattern to match against. Must not be
               null.
str –     The path to match, as a String. Must not be
               null.
Returns:
whether or not a given path matches the start of a given
pattern up to the first "**"./**
     * 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 "**".

This is not a general purpose test and should only be used if you
can live with false positives. For example, pattern=**\a
and str=b will yield true.
Params:
pattern – The pattern to match against. Must not be
               null.
str –     The path to match, as a String. Must not be
               null.
isCaseSensitive – Whether or not matching should be performed
                       case sensitively.
Returns:
whether or not a given path matches the start of a given
pattern up to the first "**"./**
     * 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);
        return matchPatternStart(patDirs, strDirs, isCaseSensitive);
    }


    
Tests whether or not a given path matches the start of a given
pattern up to the first "**".

This is not a general purpose test and should only be used if you
can live with false positives. For example, pattern=**\a
and str=b will yield true.
Params:
patDirs – The tokenized pattern to match against. Must not be
               null.
strDirs – The tokenized path to match. Must not be
               null.
isCaseSensitive – Whether or not matching should be performed
                       case sensitively.
Returns:
whether or not a given path matches the start of a given
pattern up to the first "**"./**
     * 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 patDirs The tokenized pattern to match against. Must not be
     *                <code>null</code>.
     * @param strDirs The tokenized path to match. 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 "**".
     */
    static boolean matchPatternStart(String[] patDirs, String[] strDirs,
                                     boolean isCaseSensitive) {
        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(DEEP_TREE_MATCH)) {
                break;
            }
            if (!match(patDir, strDirs[strIdxStart], isCaseSensitive)) {
                return false;
            }
            patIdxStart++;
            strIdxStart++;
        }

        // Fail if string is not exhausted or pattern is exhausted
        // Otherwise the pattern now holds ** while string is not exhausted
        // this will generate false positives but we can live with that.
        return strIdxStart > strIdxEnd || patIdxStart <= patIdxEnd;
    }

    
Tests whether or not a given path matches a given pattern.
If you need to call this method multiple times with the same
pattern you should rather use TokenizedPath
Params:
pattern – The pattern to match against. Must not be
               null.
str –     The path to match, as a String. Must not be
               null.
See Also:
TokenizedPath
Returns:
true if the pattern matches against the string,
        or false otherwise./**
     * Tests whether or not a given path matches a given pattern.
     *
     * If you need to call this method multiple times with the same
     * pattern you should rather use TokenizedPath
     *
     * @see TokenizedPath
     *
     * @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) {
        String[] patDirs = tokenizePathAsArray(pattern);
        return matchPath(patDirs, tokenizePathAsArray(str), true);
    }

    
Tests whether or not a given path matches a given pattern.
If you need to call this method multiple times with the same
pattern you should rather use TokenizedPattern
Params:
pattern – The pattern to match against. Must not be
               null.
str –     The path to match, as a String. Must not be
               null.
isCaseSensitive – Whether or not matching should be performed
                       case sensitively.
See Also:
TokenizedPattern
Returns:
true if the pattern matches against the string,
        or false otherwise./**
     * Tests whether or not a given path matches a given pattern.
     *
     * If you need to call this method multiple times with the same
     * pattern you should rather use TokenizedPattern
     *
     * @see TokenizedPattern
     *
     * @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);
        return matchPath(patDirs, tokenizePathAsArray(str), isCaseSensitive);
    }

    
Core implementation of matchPath.  It is isolated so that it
can be called from TokenizedPattern.
/**
     * Core implementation of matchPath.  It is isolated so that it
     * can be called from TokenizedPattern.
     */
    static boolean matchPath(String[] tokenizedPattern, String[] strDirs,
                             boolean isCaseSensitive) {
        int patIdxStart = 0;
        int patIdxEnd = tokenizedPattern.length - 1;
        int strIdxStart = 0;
        int strIdxEnd = strDirs.length - 1;

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

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

        while (patIdxStart != patIdxEnd && strIdxStart <= strIdxEnd) {
            int patIdxTmp = -1;
            for (int i = patIdxStart + 1; i <= patIdxEnd; i++) {
                if (tokenizedPattern[i].equals(DEEP_TREE_MATCH)) {
                    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 = tokenizedPattern[patIdxStart + j + 1];
                    String subStr = strDirs[strIdxStart + i + j];
                    if (!match(subPat, subStr, isCaseSensitive)) {
                        continue strLoop;
                    }
                }
                foundIdx = strIdxStart + i;
                break;
            }
            if (foundIdx == -1) {
                return false;
            }

            patIdxStart = patIdxTmp;
            strIdxStart = foundIdx + patLength;
        }

        for (int i = patIdxStart; i <= patIdxEnd; i++) {
            if (!DEEP_TREE_MATCH.equals(tokenizedPattern[i])) {
                return false;
            }
        }
        return true;
    }

    
Tests whether or not a string matches against a pattern.
The pattern may contain two special characters:

'*' means zero or more characters

'?' means one and only one character
Params:
pattern – The pattern to match against.
               Must not be null.
str –     The string which must be matched against the pattern.
               Must not be null.
Returns:
true if the string matches against the pattern,
        or false otherwise./**
     * 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:

'*' means zero or more characters

'?' means one and only one character
Params:
pattern – The pattern to match against.
               Must not be null.
str –     The string which must be matched against the pattern.
               Must not be null.
caseSensitive – Whether or not matching should be performed
                       case sensitively.
Returns:
true if the string matches against the pattern,
        or false otherwise./**
     * 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 caseSensitive 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 caseSensitive) {
        char[] patArr = pattern.toCharArray();
        char[] strArr = str.toCharArray();
        int patIdxStart = 0;
        int patIdxEnd = patArr.length - 1;
        int strIdxStart = 0;
        int strIdxEnd = strArr.length - 1;

        boolean containsStar = false;
        for (char ch : patArr) {
            if (ch == '*') {
                containsStar = true;
                break;
            }
        }

        if (!containsStar) {
            // No '*'s, so we make a shortcut
            if (patIdxEnd != strIdxEnd) {
                return false; // Pattern and string do not have the same size
            }
            for (int i = 0; i <= patIdxEnd; i++) {
                char ch = patArr[i];
                if (ch != '?' && different(caseSensitive, ch, strArr[i])) {
                    return false; // Character mismatch
                }
            }
            return true; // String matches against pattern
        }

        if (patIdxEnd == 0) {
            return true; // Pattern contains only '*', which matches anything
        }

        // Process characters before first star
        while (true) {
            char ch = patArr[patIdxStart];
            if (ch == '*' || strIdxStart > strIdxEnd) {
                break;
            }
            if (ch != '?'
                && different(caseSensitive, ch, strArr[strIdxStart])) {
                return false; // Character mismatch
            }
            patIdxStart++;
            strIdxStart++;
        }
        if (strIdxStart > strIdxEnd) {
            // All characters in the string are used. Check if only '*'s are
            // left in the pattern. If so, we succeeded. Otherwise failure.
            return allStars(patArr, patIdxStart, patIdxEnd);
        }

        // Process characters after last star
        while (true) {
            char ch = patArr[patIdxEnd];
            if (ch == '*' || strIdxStart > strIdxEnd) {
                break;
            }
            if (ch != '?' && different(caseSensitive, ch, strArr[strIdxEnd])) {
                return false; // Character mismatch
            }
            patIdxEnd--;
            strIdxEnd--;
        }
        if (strIdxStart > strIdxEnd) {
            // All characters in the string are used. Check if only '*'s are
            // left in the pattern. If so, we succeeded. Otherwise failure.
            return allStars(patArr, patIdxStart, patIdxEnd);
        }

        // process pattern between stars. padIdxStart and patIdxEnd point
        // always to a '*'.
        while (patIdxStart != patIdxEnd && strIdxStart <= strIdxEnd) {
            int patIdxTmp = -1;
            for (int i = patIdxStart + 1; i <= patIdxEnd; i++) {
                if (patArr[i] == '*') {
                    patIdxTmp = i;
                    break;
                }
            }
            if (patIdxTmp == patIdxStart + 1) {
                // Two stars next to each other, skip the first 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++) {
                    char ch = patArr[patIdxStart + j + 1];
                    if (ch != '?' && different(caseSensitive, ch,
                        strArr[strIdxStart + i + j])) {
                        continue strLoop;
                    }
                }
                foundIdx = strIdxStart + i;
                break;
            }

            if (foundIdx == -1) {
                return false;
            }
            patIdxStart = patIdxTmp;
            strIdxStart = foundIdx + patLength;
        }

        // All characters in the string are used. Check if only '*'s are left
        // in the pattern. If so, we succeeded. Otherwise failure.
        return allStars(patArr, patIdxStart, patIdxEnd);
    }

    private static boolean allStars(char[] chars, int start, int end) {
        for (int i = start; i <= end; ++i) {
            if (chars[i] != '*') {
                return false;
            }
        }
        return true;
    }

    private static boolean different(
        boolean caseSensitive, char ch, char other) {
        return caseSensitive
            ? ch != other
            : Character.toUpperCase(ch) != Character.toUpperCase(other);
    }

    
Breaks a path up into a Vector of path elements, tokenizing on
File.separator.
Params:
path – Path to tokenize. Must not be null.
Returns:
a Vector of path elements from the tokenized path/**
     * Breaks a path up into a Vector of path elements, tokenizing on
     * <code>File.separator</code>.
     *
     * @param path Path to tokenize. Must not be <code>null</code>.
     *
     * @return a Vector of path elements from the tokenized path
     */
    public static Vector<String> tokenizePath(String path) {
        return tokenizePath(path, File.separator);
    }

    
Breaks a path up into a Vector of path elements, tokenizing on
Params:
path – Path to tokenize. Must not be null.
separator – the separator against which to tokenize.
Returns:
a Vector of path elements from the tokenized path
Since:
Ant 1.6/**
     * Breaks a path up into a Vector of path elements, tokenizing on
     *
     * @param path Path to tokenize. Must not be <code>null</code>.
     * @param separator the separator against which to tokenize.
     *
     * @return a Vector of path elements from the tokenized path
     * @since Ant 1.6
     */
    public static Vector<String> tokenizePath(String path, String separator) {
        Vector<String> ret = new Vector<>();
        if (FileUtils.isAbsolutePath(path)) {
            String[] s = FILE_UTILS.dissect(path);
            ret.add(s[0]);
            path = s[1];
        }
        StringTokenizer st = new StringTokenizer(path, separator);
        while (st.hasMoreTokens()) {
            ret.addElement(st.nextToken());
        }
        return ret;
    }

    
Same as tokenizePath but hopefully faster. /**
     * Same as {@link #tokenizePath tokenizePath} but hopefully faster.
     */
    /* package */
    static String[] tokenizePathAsArray(String path) {
        String root = null;
        if (FileUtils.isAbsolutePath(path)) {
            String[] s = FILE_UTILS.dissect(path);
            root = s[0];
            path = s[1];
        }
        char sep = File.separatorChar;
        int start = 0;
        int len = path.length();
        int count = 0;
        for (int pos = 0; pos < len; pos++) {
            if (path.charAt(pos) == sep) {
                if (pos != start) {
                    count++;
                }
                start = pos + 1;
            }
        }
        if (len != start) {
            count++;
        }
        String[] l = new String[count + ((root == null) ? 0 : 1)];

        if (root != null) {
            l[0] = root;
            count = 1;
        } else {
            count = 0;
        }
        start = 0;
        for (int pos = 0; pos < len; pos++) {
            if (path.charAt(pos) == sep) {
                if (pos != start) {
                    String tok = path.substring(start, pos);
                    l[count++] = tok;
                }
                start = pos + 1;
            }
        }
        if (len != start) {
            String tok = path.substring(start);
            l[count/*++*/] = tok;
        }
        return l;
    }

    
Returns dependency information on these two files. If src has been
modified later than target, it returns true. If target doesn't exist,
it likewise returns true. Otherwise, target is newer than src and
is not out of date, thus the method returns false. It also returns
false if the src file doesn't even exist, since how could the
target then be out of date.
Params:
src – the original file
target – the file being compared against
granularity – the amount in seconds of slack we will give in
       determining out of dateness
Returns:
whether the target is out of date/**
     * Returns dependency information on these two files. If src has been
     * modified later than target, it returns true. If target doesn't exist,
     * it likewise returns true. Otherwise, target is newer than src and
     * is not out of date, thus the method returns false. It also returns
     * false if the src file doesn't even exist, since how could the
     * target then be out of date.
     *
     * @param src the original file
     * @param target the file being compared against
     * @param granularity the amount in seconds of slack we will give in
     *        determining out of dateness
     * @return whether the target is out of date
     */
    public static boolean isOutOfDate(File src, File target, int granularity) {
        return src.exists() && (!target.exists()
                || (src.lastModified() - granularity) > target.lastModified());
    }

    
Returns dependency information on these two resources. If src has been
modified later than target, it returns true. If target doesn't exist,
it likewise returns true. Otherwise, target is newer than src and
is not out of date, thus the method returns false. It also returns
false if the src file doesn't even exist, since how could the
target then be out of date.
Params:
src – the original resource
target – the resource being compared against
granularity – the int amount in seconds of slack we will give in
       determining out of dateness
Returns:
whether the target is out of date/**
     * Returns dependency information on these two resources. If src has been
     * modified later than target, it returns true. If target doesn't exist,
     * it likewise returns true. Otherwise, target is newer than src and
     * is not out of date, thus the method returns false. It also returns
     * false if the src file doesn't even exist, since how could the
     * target then be out of date.
     *
     * @param src the original resource
     * @param target the resource being compared against
     * @param granularity the int amount in seconds of slack we will give in
     *        determining out of dateness
     * @return whether the target is out of date
     */
    public static boolean isOutOfDate(Resource src, Resource target,
                                      int granularity) {
        return isOutOfDate(src, target, (long) granularity);
    }

    
Returns dependency information on these two resources. If src has been
modified later than target, it returns true. If target doesn't exist,
it likewise returns true. Otherwise, target is newer than src and
is not out of date, thus the method returns false. It also returns
false if the src file doesn't even exist, since how could the
target then be out of date.
Params:
src – the original resource
target – the resource being compared against
granularity – the long amount in seconds of slack we will give in
       determining out of dateness
Returns:
whether the target is out of date/**
     * Returns dependency information on these two resources. If src has been
     * modified later than target, it returns true. If target doesn't exist,
     * it likewise returns true. Otherwise, target is newer than src and
     * is not out of date, thus the method returns false. It also returns
     * false if the src file doesn't even exist, since how could the
     * target then be out of date.
     *
     * @param src the original resource
     * @param target the resource being compared against
     * @param granularity the long amount in seconds of slack we will give in
     *        determining out of dateness
     * @return whether the target is out of date
     */
    public static boolean isOutOfDate(Resource src, Resource target, long granularity) {
        long sourceLastModified = src.getLastModified();
        long targetLastModified = target.getLastModified();
        return src.isExists()
                && (sourceLastModified == Resource.UNKNOWN_DATETIME
                        || targetLastModified == Resource.UNKNOWN_DATETIME
                                || (sourceLastModified - granularity) > targetLastModified);
    }

    
"Flattens" a string by removing all whitespace (space, tab, linefeed,
carriage return, and formfeed). This uses StringTokenizer and the
default set of tokens as documented in the single argument constructor.
Params:
input – a String to remove all whitespace.
Returns:
a String that has had all whitespace removed./**
     * "Flattens" a string by removing all whitespace (space, tab, linefeed,
     * carriage return, and formfeed). This uses StringTokenizer and the
     * default set of tokens as documented in the single argument constructor.
     *
     * @param input a String to remove all whitespace.
     * @return a String that has had all whitespace removed.
     */
    public static String removeWhitespace(String input) {
        StringBuilder result = new StringBuilder();
        if (input != null) {
            StringTokenizer st = new StringTokenizer(input);
            while (st.hasMoreTokens()) {
                result.append(st.nextToken());
            }
        }
        return result.toString();
    }

    
Tests if a string contains stars or question marks
Params:
input – a String which one wants to test for containing wildcard
Returns:
true if the string contains at least a star or a question mark/**
     * Tests if a string contains stars or question marks
     * @param input a String which one wants to test for containing wildcard
     * @return true if the string contains at least a star or a question mark
     */
    public static boolean hasWildcards(String input) {
        return input.contains("*") || input.contains("?");
    }

    
removes from a pattern all tokens to the right containing wildcards
Params:
input – the input string
Returns:
the leftmost part of the pattern without wildcards/**
     * removes from a pattern all tokens to the right containing wildcards
     * @param input the input string
     * @return the leftmost part of the pattern without wildcards
     */
    public static String rtrimWildcardTokens(String input) {
        return new TokenizedPattern(input).rtrimWildcardTokens().toString();
    }
}