content: /*
   * Copyright 2002-2021 the original author or authors.
   *
   * Licensed 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 com.alibaba.nacos.common.packagescan.resource;
  
  import com.alibaba.nacos.common.packagescan.util.PathMatcher;
  import com.alibaba.nacos.common.packagescan.util.AbstractAssert;
  import com.alibaba.nacos.common.utils.StringUtils;
  
  import java.util.ArrayList;
  import java.util.Comparator;
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  /**
   * Copy from https://github.com/spring-projects/spring-framework.git, with less modifications
   * {@link PathMatcher} implementation for Ant-style path patterns.
   * Part of this mapping code has been kindly borrowed from <a href="https://ant.apache.org">Apache Ant</a>.
   * The mapping matches URLs using the following rules:<br>
   * <ul>
   * <li>{@code ?} matches one character</li>
   * <li>{@code *} matches zero or more characters</li>
   * <li>{@code **} matches zero or more <em>directories</em> in a path</li>
   * <li>{@code {spring:[a-z]+}} matches the regexp {@code [a-z]+} as a path variable named "spring"</li>
   * </ul>
   *
   * <h3>Examples</h3>
   * <ul>
   * <li>{@code com/t?st.jsp} &mdash; matches {@code com/test.jsp} but also
   * {@code com/tast.jsp} or {@code com/txst.jsp}</li>
   * <li>{@code com/*.jsp} &mdash; matches all {@code .jsp} files in the
   * {@code com} directory</li>
   * <li><code>com/&#42;&#42;/test.jsp</code> &mdash; matches all {@code test.jsp}
   * files underneath the {@code com} path</li>
   * <li><code>org/springframework/&#42;&#42;/*.jsp</code> &mdash; matches all
   * {@code .jsp} files underneath the {@code org/springframework} path</li>
   * <li><code>org/&#42;&#42;/servlet/bla.jsp</code> &mdash; matches
   * {@code org/springframework/servlet/bla.jsp} but also
   * {@code org/springframework/testing/servlet/bla.jsp} and {@code org/servlet/bla.jsp}</li>
   * <li>{@code com/{filename:\\w+}.jsp} will match {@code com/test.jsp} and assign the value {@code test}
   * to the {@code filename} variable</li>
   * </ul>
   *
   * <strong>Note:</strong> a pattern and a path must both be absolute or must
   * both be relative in order for the two to match. Therefore it is recommended
   * that users of this implementation to sanitize patterns in order to prefix
   * them with "/" as it makes sense in the context in which they're used.
   *
   * @author Alef Arendsen
   * @author Juergen Hoeller
   * @author Rob Harrop
   * @author Arjen Poutsma
   * @author Rossen Stoyanchev
   * @author Sam Brannen
   * @author Vladislav Kisel
   * @since 16.07.2003
   */
  public class AntPathMatcher implements PathMatcher {
  
      /**
       * Default path separator: "/".
       */
      public static final String DEFAULT_PATH_SEPARATOR = "/";
  
      private static final int CACHE_TURNOFF_THRESHOLD = 65536;
  
      private static final Pattern VARIABLE_PATTERN = Pattern.compile("\\{[^/]+?\\}");
  
      private static final char[] WILDCARD_CHARS = {'*', '?', '{'};
  
      private String pathSeparator;
  
      private PathSeparatorPatternCache pathSeparatorPatternCache;
  
      private boolean caseSensitive = true;
  
      private boolean trimTokens = false;
  
      private volatile Boolean cachePatterns;
  
      private final Map<String, String[]> tokenizedPatternCache = new ConcurrentHashMap<>(256);
  
      final Map<String, AntPathStringMatcher> stringMatcherCache = new ConcurrentHashMap<>(256);
  
      /**
       * Create a new instance with the {@link #DEFAULT_PATH_SEPARATOR}.
       */
      public AntPathMatcher() {
          this.pathSeparator = DEFAULT_PATH_SEPARATOR;
          this.pathSeparatorPatternCache = new PathSeparatorPatternCache(DEFAULT_PATH_SEPARATOR);
      }
  
      /**
       * A convenient, alternative constructor to use with a custom path separator.
       *
       * @param pathSeparator the path separator to use, must not be {@code null}.
       * @since 4.1
       */
      public AntPathMatcher(String pathSeparator) {
          AbstractAssert.notNull(pathSeparator, "'pathSeparator' is required");
          this.pathSeparator = pathSeparator;
          this.pathSeparatorPatternCache = new PathSeparatorPatternCache(pathSeparator);
      }
  
      /**
       * Set the path separator to use for pattern parsing.
       * Default is "/", as in Ant.
       */
      public void setPathSeparator(String pathSeparator) {
          this.pathSeparator = (pathSeparator != null ? pathSeparator : DEFAULT_PATH_SEPARATOR);
          this.pathSeparatorPatternCache = new PathSeparatorPatternCache(this.pathSeparator);
      }
  
      /**
       * Specify whether to perform pattern matching in a case-sensitive fashion.
       * Default is {@code true}. Switch this to {@code false} for case-insensitive matching.
       *
       * @since 4.2
       */
      public void setCaseSensitive(boolean caseSensitive) {
          this.caseSensitive = caseSensitive;
      }
  
      /**
       * Specify whether to trim tokenized paths and patterns.
       * Default is {@code false}.
       */
      public void setTrimTokens(boolean trimTokens) {
          this.trimTokens = trimTokens;
      }
  
      /**
       * Specify whether to cache parsed pattern metadata for patterns passed
       * into this matcher's {@link #match} method. A value of {@code true}
       * activates an unlimited pattern cache; a value of {@code false} turns
       * the pattern cache off completely.
       * Default is for the cache to be on, but with the variant to automatically
       * turn it off when encountering too many patterns to cache at runtime
       * (the threshold is 65536), assuming that arbitrary permutations of patterns
       * are coming in, with little chance for encountering a recurring pattern.
       *
       * @see #getStringMatcher(String)
       * @since 4.0.1
       */
      public void setCachePatterns(boolean cachePatterns) {
          this.cachePatterns = cachePatterns;
      }
  
      private void deactivatePatternCache() {
          this.cachePatterns = false;
          this.tokenizedPatternCache.clear();
          this.stringMatcherCache.clear();
      }
  
      @Override
      public boolean isPattern(String path) {
          if (path == null) {
              return false;
          }
          boolean uriVar = false;
          for (int i = 0; i < path.length(); i++) {
              char c = path.charAt(i);
              if (c == '*' || c == '?') {
                  return true;
              }
              if (c == '{') {
                  uriVar = true;
                  continue;
              }
              if (c == '}' && uriVar) {
                  return true;
              }
          }
          return false;
      }
  
      @Override
      public boolean match(String pattern, String path) {
          return doMatch(pattern, path, true, null);
      }
  
      @Override
      public boolean matchStart(String pattern, String path) {
          return doMatch(pattern, path, false, null);
      }
  
      /**
       * Actually match the given {@code path} against the given {@code pattern}.
       *
       * @param pattern   the pattern to match against
       * @param path      the path to test
       * @param fullMatch whether a full pattern match is required (else a pattern match
       *                  as far as the given base path goes is sufficient)
       * @return {@code true} if the supplied {@code path} matched, {@code false} if it didn't
       */
      protected boolean doMatch(String pattern, String path, boolean fullMatch,
                                Map<String, String> uriTemplateVariables) {
  
          if (path == null || path.startsWith(this.pathSeparator) != pattern.startsWith(this.pathSeparator)) {
              return false;
          }
  
          String[] pattDirs = tokenizePattern(pattern);
          if (fullMatch && this.caseSensitive && !isPotentialMatch(path, pattDirs)) {
              return false;
          }
  
          String[] pathDirs = tokenizePath(path);
          int pattIdxStart = 0;
          int pattIdxEnd = pattDirs.length - 1;
          int pathIdxStart = 0;
          int pathIdxEnd = pathDirs.length - 1;
  
          // Match all elements up to the first **
          while (pattIdxStart <= pattIdxEnd && pathIdxStart <= pathIdxEnd) {
              String pattDir = pattDirs[pattIdxStart];
              if ("**".equals(pattDir)) {
                  break;
              }
              if (!matchStrings(pattDir, pathDirs[pathIdxStart], uriTemplateVariables)) {
                  return false;
              }
              pattIdxStart++;
              pathIdxStart++;
          }
  
          if (pathIdxStart > pathIdxEnd) {
              // Path is exhausted, only match if rest of pattern is * or **'s
              if (pattIdxStart > pattIdxEnd) {
                  return (pattern.endsWith(this.pathSeparator) == path.endsWith(this.pathSeparator));
              }
              if (!fullMatch) {
                  return true;
              }
              if (pattIdxStart == pattIdxEnd && pattDirs[pattIdxStart].equals("*") && path.endsWith(this.pathSeparator)) {
                  return true;
              }
              for (int i = pattIdxStart; i <= pattIdxEnd; i++) {
                  if (!pattDirs[i].equals("**")) {
                      return false;
                  }
              }
              return true;
          } else if (pattIdxStart > pattIdxEnd) {
              // String not exhausted, but pattern is. Failure.
              return false;
          } else if (!fullMatch && "**".equals(pattDirs[pattIdxStart])) {
              // Path start definitely matches due to "**" part in pattern.
              return true;
          }
  
          // up to last '**'
          while (pattIdxStart <= pattIdxEnd && pathIdxStart <= pathIdxEnd) {
              String pattDir = pattDirs[pattIdxEnd];
              if (pattDir.equals("**")) {
                  break;
              }
              if (!matchStrings(pattDir, pathDirs[pathIdxEnd], uriTemplateVariables)) {
                  return false;
              }
              pattIdxEnd--;
              pathIdxEnd--;
          }
          if (pathIdxStart > pathIdxEnd) {
              // String is exhausted
              for (int i = pattIdxStart; i <= pattIdxEnd; i++) {
                  if (!pattDirs[i].equals("**")) {
                      return false;
                  }
              }
              return true;
          }
  
          while (pattIdxStart != pattIdxEnd && pathIdxStart <= pathIdxEnd) {
              int patIdxTmp = -1;
              for (int i = pattIdxStart + 1; i <= pattIdxEnd; i++) {
                  if (pattDirs[i].equals("**")) {
                      patIdxTmp = i;
                      break;
                  }
              }
              if (patIdxTmp == pattIdxStart + 1) {
                  // '**/**' situation, so skip one
                  pattIdxStart++;
                  continue;
              }
              // Find the pattern between padIdxStart & padIdxTmp in str between
              // strIdxStart & strIdxEnd
              int patLength = (patIdxTmp - pattIdxStart - 1);
              int strLength = (pathIdxEnd - pathIdxStart + 1);
              int foundIdx = -1;
  
              strLoop:
              for (int i = 0; i <= strLength - patLength; i++) {
                  for (int j = 0; j < patLength; j++) {
                      String subPat = pattDirs[pattIdxStart + j + 1];
                      String subStr = pathDirs[pathIdxStart + i + j];
                      if (!matchStrings(subPat, subStr, uriTemplateVariables)) {
                          continue strLoop;
                      }
                  }
                  foundIdx = pathIdxStart + i;
                  break;
              }
  
              if (foundIdx == -1) {
                  return false;
              }
  
              pattIdxStart = patIdxTmp;
              pathIdxStart = foundIdx + patLength;
          }
  
          for (int i = pattIdxStart; i <= pattIdxEnd; i++) {
              if (!pattDirs[i].equals("**")) {
                  return false;
              }
          }
  
          return true;
      }
  
      private boolean isPotentialMatch(String path, String[] pattDirs) {
          if (!this.trimTokens) {
              int pos = 0;
              for (String pattDir : pattDirs) {
                  int skipped = skipSeparator(path, pos, this.pathSeparator);
                  pos += skipped;
                  skipped = skipSegment(path, pos, pattDir);
                  if (skipped < pattDir.length()) {
                      return (skipped > 0 || (pattDir.length() > 0 && isWildcardChar(pattDir.charAt(0))));
                  }
                  pos += skipped;
              }
          }
          return true;
      }
  
      private int skipSegment(String path, int pos, String prefix) {
          int skipped = 0;
          for (int i = 0; i < prefix.length(); i++) {
              char c = prefix.charAt(i);
              if (isWildcardChar(c)) {
                  return skipped;
              }
              int currPos = pos + skipped;
              if (currPos >= path.length()) {
                  return 0;
              }
              if (c == path.charAt(currPos)) {
                  skipped++;
              }
          }
          return skipped;
      }
  
      private int skipSeparator(String path, int pos, String separator) {
          int skipped = 0;
          while (path.startsWith(separator, pos + skipped)) {
              skipped += separator.length();
          }
          return skipped;
      }
  
      private boolean isWildcardChar(char c) {
          for (char candidate : WILDCARD_CHARS) {
              if (c == candidate) {
                  return true;
              }
          }
          return false;
      }
  
      /**
       * Tokenize the given path pattern into parts, based on this matcher's settings.
       * Performs caching based on {@link #setCachePatterns}, delegating to
       * {@link #tokenizePath(String)} for the actual tokenization algorithm.
       *
       * @param pattern the pattern to tokenize
       * @return the tokenized pattern parts
       */
      protected String[] tokenizePattern(String pattern) {
          String[] tokenized = null;
          Boolean cachePatterns = this.cachePatterns;
          if (cachePatterns == null || cachePatterns.booleanValue()) {
              tokenized = this.tokenizedPatternCache.get(pattern);
          }
          if (tokenized == null) {
              tokenized = tokenizePath(pattern);
              if (cachePatterns == null && this.tokenizedPatternCache.size() >= CACHE_TURNOFF_THRESHOLD) {
                  // Try to adapt to the runtime situation that we're encountering:
                  // There are obviously too many different patterns coming in here...
                  // So let's turn off the cache since the patterns are unlikely to be reoccurring.
                  deactivatePatternCache();
                  return tokenized;
              }
              if (cachePatterns == null || cachePatterns.booleanValue()) {
                  this.tokenizedPatternCache.put(pattern, tokenized);
              }
          }
          return tokenized;
      }
  
      /**
       * Tokenize the given path into parts, based on this matcher's settings.
       *
       * @param path the path to tokenize
       * @return the tokenized path parts
       */
      protected String[] tokenizePath(String path) {
          return StringUtils.tokenizeToStringArray(path, this.pathSeparator, this.trimTokens, true);
      }
  
      /**
       * Test whether or not a string matches against a pattern.
       *
       * @param pattern the pattern to match against (never {@code null})
       * @param str     the String which must be matched against the pattern (never {@code null})
       * @return {@code true} if the string matches against the pattern, or {@code false} otherwise
       */
      private boolean matchStrings(String pattern, String str,
                                   Map<String, String> uriTemplateVariables) {
  
          return getStringMatcher(pattern).matchStrings(str, uriTemplateVariables);
      }
  
      /**
       * Build or retrieve an {@link AntPathStringMatcher} for the given pattern.
       * The default implementation checks this AntPathMatcher's internal cache
       * (see {@link #setCachePatterns}), creating a new AntPathStringMatcher instance
       * if no cached copy is found.
       * When encountering too many patterns to cache at runtime (the threshold is 65536),
       * it turns the default cache off, assuming that arbitrary permutations of patterns
       * are coming in, with little chance for encountering a recurring pattern.
       * This method may be overridden to implement a custom cache strategy.
       *
       * @param pattern the pattern to match against (never {@code null})
       * @return a corresponding AntPathStringMatcher (never {@code null})
       * @see #setCachePatterns
       */
      protected AntPathStringMatcher getStringMatcher(String pattern) {
          AntPathStringMatcher matcher = null;
          Boolean cachePatterns = this.cachePatterns;
          if (cachePatterns == null || cachePatterns.booleanValue()) {
              matcher = this.stringMatcherCache.get(pattern);
          }
          if (matcher == null) {
              matcher = new AntPathStringMatcher(pattern, this.caseSensitive);
              if (cachePatterns == null && this.stringMatcherCache.size() >= CACHE_TURNOFF_THRESHOLD) {
                  // Try to adapt to the runtime situation that we're encountering:
                  // There are obviously too many different patterns coming in here...
                  // So let's turn off the cache since the patterns are unlikely to be reoccurring.
                  deactivatePatternCache();
                  return matcher;
              }
              if (cachePatterns == null || cachePatterns.booleanValue()) {
                  this.stringMatcherCache.put(pattern, matcher);
              }
          }
          return matcher;
      }
  
      /**
       * Given a pattern and a full path, determine the pattern-mapped part. For example: <ul>
       * <li>'{@code /docs/cvs/commit.html}' and '{@code /docs/cvs/commit.html} &rarr; ''</li>
       * <li>'{@code /docs/*}' and '{@code /docs/cvs/commit} &rarr; '{@code cvs/commit}'</li>
       * <li>'{@code /docs/cvs/*.html}' and '{@code /docs/cvs/commit.html} &rarr; '{@code commit.html}'</li>
       * <li>'{@code /docs/**}' and '{@code /docs/cvs/commit} &rarr; '{@code cvs/commit}'</li>
       * <li>'{@code /docs/**\/*.html}' and '{@code /docs/cvs/commit.html} &rarr; '{@code cvs/commit.html}'</li>
       * <li>'{@code /*.html}' and '{@code /docs/cvs/commit.html} &rarr; '{@code docs/cvs/commit.html}'</li>
       * <li>'{@code *.html}' and '{@code /docs/cvs/commit.html} &rarr; '{@code /docs/cvs/commit.html}'</li>
       * <li>'{@code *}' and '{@code /docs/cvs/commit.html} &rarr; '{@code /docs/cvs/commit.html}'</li> </ul>
       * Assumes that {@link #match} returns {@code true} for '{@code pattern}' and '{@code path}', but
       * does <strong>not</strong> enforce this.
       */
      @Override
      public String extractPathWithinPattern(String pattern, String path) {
          String[] patternParts = StringUtils.tokenizeToStringArray(pattern, this.pathSeparator, this.trimTokens, true);
          String[] pathParts = StringUtils.tokenizeToStringArray(path, this.pathSeparator, this.trimTokens, true);
          StringBuilder builder = new StringBuilder();
          boolean pathStarted = false;
  
          for (int segment = 0; segment < patternParts.length; segment++) {
              String patternPart = patternParts[segment];
              if (patternPart.indexOf('*') > -1 || patternPart.indexOf('?') > -1) {
                  for (; segment < pathParts.length; segment++) {
                      if (pathStarted || (segment == 0 && !pattern.startsWith(this.pathSeparator))) {
                          builder.append(this.pathSeparator);
                      }
                      builder.append(pathParts[segment]);
                      pathStarted = true;
                  }
              }
          }
  
          return builder.toString();
      }
  
      @Override
      public Map<String, String> extractUriTemplateVariables(String pattern, String path) {
          Map<String, String> variables = new LinkedHashMap<>();
          boolean result = doMatch(pattern, path, true, variables);
          if (!result) {
              throw new IllegalStateException("Pattern \"" + pattern + "\" is not a match for \"" + path + "\"");
          }
          return variables;
      }
  
      /**
       * Combine two patterns into a new pattern.
       * This implementation simply concatenates the two patterns, unless
       * the first pattern contains a file extension match (e.g., {@code *.html}).
       * In that case, the second pattern will be merged into the first. Otherwise,
       * an {@code IllegalArgumentException} will be thrown.
       * <h3>Examples</h3>
       * <table border="1">
       * <tr><th>Pattern 1</th><th>Pattern 2</th><th>Result</th></tr>
       * <tr><td>{@code null}</td><td>{@code null}</td><td>&nbsp;</td></tr>
       * <tr><td>/hotels</td><td>{@code null}</td><td>/hotels</td></tr>
       * <tr><td>{@code null}</td><td>/hotels</td><td>/hotels</td></tr>
       * <tr><td>/hotels</td><td>/bookings</td><td>/hotels/bookings</td></tr>
       * <tr><td>/hotels</td><td>bookings</td><td>/hotels/bookings</td></tr>
       * <tr><td>/hotels/*</td><td>/bookings</td><td>/hotels/bookings</td></tr>
       * <tr><td>/hotels/&#42;&#42;</td><td>/bookings</td><td>/hotels/&#42;&#42;/bookings</td></tr>
       * <tr><td>/hotels</td><td>{hotel}</td><td>/hotels/{hotel}</td></tr>
       * <tr><td>/hotels/*</td><td>{hotel}</td><td>/hotels/{hotel}</td></tr>
       * <tr><td>/hotels/&#42;&#42;</td><td>{hotel}</td><td>/hotels/&#42;&#42;/{hotel}</td></tr>
       * <tr><td>/*.html</td><td>/hotels.html</td><td>/hotels.html</td></tr>
       * <tr><td>/*.html</td><td>/hotels</td><td>/hotels.html</td></tr>
       * <tr><td>/*.html</td><td>/*.txt</td><td>{@code IllegalArgumentException}</td></tr>
       * </table>
       *
       * @param pattern1 the first pattern
       * @param pattern2 the second pattern
       * @return the combination of the two patterns
       * @throws IllegalArgumentException if the two patterns cannot be combined
       */
      @Override
      public String combine(String pattern1, String pattern2) {
          if (!StringUtils.hasText(pattern1) && !StringUtils.hasText(pattern2)) {
              return "";
          }
          if (!StringUtils.hasText(pattern1)) {
              return pattern2;
          }
          if (!StringUtils.hasText(pattern2)) {
              return pattern1;
          }
  
          boolean pattern1ContainsUriVar = (pattern1.indexOf('{') != -1);
          if (!pattern1.equals(pattern2) && !pattern1ContainsUriVar && match(pattern1, pattern2)) {
              // /* + /hotel -> /hotel ; "/*.*" + "/*.html" -> /*.html
              // However /user + /user -> /usr/user ; /{foo} + /bar -> /{foo}/bar
              return pattern2;
          }
  
          // /hotels/* + /booking -> /hotels/booking
          // /hotels/* + booking -> /hotels/booking
          if (pattern1.endsWith(this.pathSeparatorPatternCache.getEndsOnWildCard())) {
              return concat(pattern1.substring(0, pattern1.length() - 2), pattern2);
          }
  
          // /hotels/** + /booking -> /hotels/**/booking
          // /hotels/** + booking -> /hotels/**/booking
          if (pattern1.endsWith(this.pathSeparatorPatternCache.getEndsOnDoubleWildCard())) {
              return concat(pattern1, pattern2);
          }
  
          int starDotPos1 = pattern1.indexOf("*.");
          if (pattern1ContainsUriVar || starDotPos1 == -1 || this.pathSeparator.equals(".")) {
              // simply concatenate the two patterns
              return concat(pattern1, pattern2);
          }
  
          String ext1 = pattern1.substring(starDotPos1 + 1);
          int dotPos2 = pattern2.indexOf('.');
          String file2 = (dotPos2 == -1 ? pattern2 : pattern2.substring(0, dotPos2));
          String ext2 = (dotPos2 == -1 ? "" : pattern2.substring(dotPos2));
          boolean ext1All = (ext1.equals(".*") || ext1.isEmpty());
          boolean ext2All = (ext2.equals(".*") || ext2.isEmpty());
          if (!ext1All && !ext2All) {
              throw new IllegalArgumentException("Cannot combine patterns: " + pattern1 + " vs " + pattern2);
          }
          String ext = (ext1All ? ext2 : ext1);
          return file2 + ext;
      }
  
      private String concat(String path1, String path2) {
          boolean path1EndsWithSeparator = path1.endsWith(this.pathSeparator);
          boolean path2StartsWithSeparator = path2.startsWith(this.pathSeparator);
  
          if (path1EndsWithSeparator && path2StartsWithSeparator) {
              return path1 + path2.substring(1);
          } else if (path1EndsWithSeparator || path2StartsWithSeparator) {
              return path1 + path2;
          } else {
              return path1 + this.pathSeparator + path2;
          }
      }
  
      /**
       * Given a full path, returns a {@link Comparator} suitable for sorting patterns in order of
       * explicitness.
       * This {@code Comparator} will {@linkplain List#sort(Comparator) sort}
       * a list so that more specific patterns (without URI templates or wild cards) come before
       * generic patterns. So given a list with the following patterns, the returned comparator
       * will sort this list so that the order will be as indicated.
       * <ol>
       * <li>{@code /hotels/new}</li>
       * <li>{@code /hotels/{hotel}}</li>
       * <li>{@code /hotels/*}</li>
       * </ol>
       * The full path given as parameter is used to test for exact matches. So when the given path
       * is {@code /hotels/2}, the pattern {@code /hotels/2} will be sorted before {@code /hotels/1}.
       *
       * @param path the full path to use for comparison
       * @return a comparator capable of sorting patterns in order of explicitness
       */
      @Override
      public Comparator<String> getPatternComparator(String path) {
          return new AntPatternComparator(path);
      }
  
      /**
       * Tests whether or not a string matches against a pattern via a {@link Pattern}.
       * The pattern may contain special characters: '*' means zero or more characters; '?' means one and
       * only one character; '{' and '}' indicate a URI template pattern. For example <tt>/users/{user}</tt>.
       */
      protected static class AntPathStringMatcher {
  
          private static final Pattern GLOB_PATTERN = Pattern.compile("\\?|\\*|\\{((?:\\{[^/]+?\\}|[^/{}]|\\\\[{}])+?)\\}");
  
          private static final String DEFAULT_VARIABLE_PATTERN = "((?s).*)";
  
          private final String rawPattern;
  
          private final boolean caseSensitive;
  
          private final boolean exactMatch;
  
          private final Pattern pattern;
  
          private final List<String> variableNames = new ArrayList<>();
  
          public AntPathStringMatcher(String pattern) {
              this(pattern, true);
          }
  
          public AntPathStringMatcher(String pattern, boolean caseSensitive) {
              this.rawPattern = pattern;
              this.caseSensitive = caseSensitive;
              StringBuilder patternBuilder = new StringBuilder();
              Matcher matcher = GLOB_PATTERN.matcher(pattern);
              int end = 0;
              while (matcher.find()) {
                  patternBuilder.append(quote(pattern, end, matcher.start()));
                  String match = matcher.group();
                  if ("?".equals(match)) {
                      patternBuilder.append('.');
                  } else if ("*".equals(match)) {
                      patternBuilder.append(".*");
                  } else if (match.startsWith("{") && match.endsWith("}")) {
                      int colonIdx = match.indexOf(':');
                      if (colonIdx == -1) {
                          patternBuilder.append(DEFAULT_VARIABLE_PATTERN);
                          this.variableNames.add(matcher.group(1));
                      } else {
                          String variablePattern = match.substring(colonIdx + 1, match.length() - 1);
                          patternBuilder.append('(');
                          patternBuilder.append(variablePattern);
                          patternBuilder.append(')');
                          String variableName = match.substring(1, colonIdx);
                          this.variableNames.add(variableName);
                      }
                  }
                  end = matcher.end();
              }
              // No glob pattern was found, this is an exact String match
              if (end == 0) {
                  this.exactMatch = true;
                  this.pattern = null;
              } else {
                  this.exactMatch = false;
                  patternBuilder.append(quote(pattern, end, pattern.length()));
                  this.pattern = (this.caseSensitive ? Pattern.compile(patternBuilder.toString()) :
                          Pattern.compile(patternBuilder.toString(), Pattern.CASE_INSENSITIVE));
              }
          }
  
          private String quote(String s, int start, int end) {
              if (start == end) {
                  return "";
              }
              return Pattern.quote(s.substring(start, end));
          }
  
          /**
           * Main entry point.
           *
           * @return {@code true} if the string matches against the pattern, or {@code false} otherwise.
           */
          public boolean matchStrings(String str, Map<String, String> uriTemplateVariables) {
              if (this.exactMatch) {
                  return this.caseSensitive ? this.rawPattern.equals(str) : this.rawPattern.equalsIgnoreCase(str);
              } else if (this.pattern != null) {
                  Matcher matcher = this.pattern.matcher(str);
                  if (matcher.matches()) {
                      if (uriTemplateVariables != null) {
                          if (this.variableNames.size() != matcher.groupCount()) {
                              throw new IllegalArgumentException("The number of capturing groups in the pattern segment "
                                      + this.pattern + " does not match the number of URI template variables it defines, "
                                      + "which can occur if capturing groups are used in a URI template regex. "
                                      + "Use non-capturing groups instead.");
                          }
                          for (int i = 1; i <= matcher.groupCount(); i++) {
                              String name = this.variableNames.get(i - 1);
                              if (name.startsWith("*")) {
                                  throw new IllegalArgumentException("Capturing patterns (" + name + ") are not "
                                          + "supported by the AntPathMatcher. Use the PathPatternParser instead.");
                              }
                              String value = matcher.group(i);
                              uriTemplateVariables.put(name, value);
                          }
                      }
                      return true;
                  }
              }
              return false;
          }
  
      }
  
      /**
       * The default {@link Comparator} implementation returned by
       * {@link #getPatternComparator(String)}.
       * In order, the most "generic" pattern is determined by the following:
       * <ul>
       * <li>if it's null or a capture all pattern (i.e. it is equal to "/**")</li>
       * <li>if the other pattern is an actual match</li>
       * <li>if it's a catch-all pattern (i.e. it ends with "**"</li>
       * <li>if it's got more "*" than the other pattern</li>
       * <li>if it's got more "{foo}" than the other pattern</li>
       * <li>if it's shorter than the other pattern</li>
       * </ul>
       */
      protected static class AntPatternComparator implements Comparator<String> {
  
          private final String path;
  
          public AntPatternComparator(String path) {
              this.path = path;
          }
  
          /**
           * Compare two patterns to determine which should match first, i.e. which
           * is the most specific regarding the current path.
           *
           * @return a negative integer, zero, or a positive integer as pattern1 is
           * more specific, equally specific, or less specific than pattern2.
           */
          @Override
          public int compare(String pattern1, String pattern2) {
              PatternInfo info1 = new PatternInfo(pattern1);
              PatternInfo info2 = new PatternInfo(pattern2);
  
              if (info1.isLeastSpecific() && info2.isLeastSpecific()) {
                  return 0;
              } else if (info1.isLeastSpecific()) {
                  return 1;
              } else if (info2.isLeastSpecific()) {
                  return -1;
              }
  
              boolean pattern1EqualsPath = pattern1.equals(this.path);
              boolean pattern2EqualsPath = pattern2.equals(this.path);
              if (pattern1EqualsPath && pattern2EqualsPath) {
                  return 0;
              } else if (pattern1EqualsPath) {
                  return -1;
              } else if (pattern2EqualsPath) {
                  return 1;
              }
  
              if (info1.isPrefixPattern() && info2.isPrefixPattern()) {
                  return info2.getLength() - info1.getLength();
              } else if (info1.isPrefixPattern() && info2.getDoubleWildcards() == 0) {
                  return 1;
              } else if (info2.isPrefixPattern() && info1.getDoubleWildcards() == 0) {
                  return -1;
              }
  
              if (info1.getTotalCount() != info2.getTotalCount()) {
                  return info1.getTotalCount() - info2.getTotalCount();
              }
  
              if (info1.getLength() != info2.getLength()) {
                  return info2.getLength() - info1.getLength();
              }
  
              if (info1.getSingleWildcards() < info2.getSingleWildcards()) {
                  return -1;
              } else if (info2.getSingleWildcards() < info1.getSingleWildcards()) {
                  return 1;
              }
  
              if (info1.getUriVars() < info2.getUriVars()) {
                  return -1;
              } else if (info2.getUriVars() < info1.getUriVars()) {
                  return 1;
              }
  
              return 0;
          }
  
          /**
           * Value class that holds information about the pattern, e.g. number of
           * occurrences of "*", "**", and "{" pattern elements.
           */
          private static class PatternInfo {
  
              private final String pattern;
  
              private int uriVars;
  
              private int singleWildcards;
  
              private int doubleWildcards;
  
              private boolean catchAllPattern;
  
              private boolean prefixPattern;
  
              private Integer length;
  
              public PatternInfo(String pattern) {
                  this.pattern = pattern;
                  if (this.pattern != null) {
                      initCounters();
                      this.catchAllPattern = this.pattern.equals("/**");
                      this.prefixPattern = !this.catchAllPattern && this.pattern.endsWith("/**");
                  }
                  if (this.uriVars == 0) {
                      this.length = (this.pattern != null ? this.pattern.length() : 0);
                  }
              }
  
              protected void initCounters() {
                  int pos = 0;
                  if (this.pattern != null) {
                      while (pos < this.pattern.length()) {
                          if (this.pattern.charAt(pos) == '{') {
                              this.uriVars++;
                              pos++;
                          } else if (this.pattern.charAt(pos) == '*') {
                              if (pos + 1 < this.pattern.length() && this.pattern.charAt(pos + 1) == '*') {
                                  this.doubleWildcards++;
                                  pos += 2;
                              } else if (pos > 0 && !this.pattern.substring(pos - 1).equals(".*")) {
                                  this.singleWildcards++;
                                  pos++;
                              } else {
                                  pos++;
                              }
                          } else {
                              pos++;
                          }
                      }
                  }
              }
  
              public int getUriVars() {
                  return this.uriVars;
              }
  
              public int getSingleWildcards() {
                  return this.singleWildcards;
              }
  
              public int getDoubleWildcards() {
                  return this.doubleWildcards;
              }
  
              public boolean isLeastSpecific() {
                  return (this.pattern == null || this.catchAllPattern);
              }
  
              public boolean isPrefixPattern() {
                  return this.prefixPattern;
              }
  
              public int getTotalCount() {
                  return this.uriVars + this.singleWildcards + (2 * this.doubleWildcards);
              }
  
              /**
               * Returns the length of the given pattern, where template variables are considered to be 1 long.
               */
              public int getLength() {
                  if (this.length == null) {
                      this.length = (this.pattern != null
                              ? VARIABLE_PATTERN.matcher(this.pattern).replaceAll("#").length() : 0);
                  }
                  return this.length;
              }
          }
      }
  
      /**
       * A simple cache for patterns that depend on the configured path separator.
       */
      private static class PathSeparatorPatternCache {
  
          private final String endsOnWildCard;
  
          private final String endsOnDoubleWildCard;
  
          public PathSeparatorPatternCache(String pathSeparator) {
              this.endsOnWildCard = pathSeparator + "*";
              this.endsOnDoubleWildCard = pathSeparator + "**";
          }
  
          public String getEndsOnWildCard() {
              return this.endsOnWildCard;
          }
  
          public String getEndsOnDoubleWildCard() {
              return this.endsOnDoubleWildCard;
          }
      }
  
  }
  