Java tutorial
/* * Copyright 2002-2019 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 org.springframework.util; import java.util.Comparator; import java.util.LinkedHashMap; import java.util.LinkedList; import java.util.List; import java.util.Map; import java.util.concurrent.ConcurrentHashMap; import java.util.regex.Matcher; import java.util.regex.Pattern; import org.springframework.lang.Nullable; /** * {@link PathMatcher} implementation for Ant-style path patterns. * * <p>Part of this mapping code has been kindly borrowed from <a href="https://ant.apache.org">Apache Ant</a>. * * <p>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} — matches {@code com/test.jsp} but also * {@code com/tast.jsp} or {@code com/txst.jsp}</li> * <li>{@code com/*.jsp} — matches all {@code .jsp} files in the * {@code com} directory</li> * <li><code>com/**/test.jsp</code> — matches all {@code test.jsp} * files underneath the {@code com} path</li> * <li><code>org/springframework/**/*.jsp</code> — matches all * {@code .jsp} files underneath the {@code org/springframework} path</li> * <li><code>org/**/servlet/bla.jsp</code> — 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> * * <p><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 * @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; @Nullable 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) { Assert.notNull(pathSeparator, "'pathSeparator' is required"); this.pathSeparator = pathSeparator; this.pathSeparatorPatternCache = new PathSeparatorPatternCache(pathSeparator); } /** * Set the path separator to use for pattern parsing. * <p>Default is "/", as in Ant. */ public void setPathSeparator(@Nullable 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. * <p>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. * <p>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. * <p>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. * @since 4.0.1 * @see #getStringMatcher(String) */ public void setCachePatterns(boolean cachePatterns) { this.cachePatterns = cachePatterns; } private void deactivatePatternCache() { this.cachePatterns = false; this.tokenizedPatternCache.clear(); this.stringMatcherCache.clear(); } @Override public boolean isPattern(@Nullable 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, @Nullable String path, boolean fullMatch, @Nullable 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. * <p>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, @Nullable Map<String, String> uriTemplateVariables) { return getStringMatcher(pattern).matchStrings(str, uriTemplateVariables); } /** * Build or retrieve an {@link AntPathStringMatcher} for the given pattern. * <p>The default implementation checks this AntPathMatcher's internal cache * (see {@link #setCachePatterns}), creating a new AntPathStringMatcher instance * if no cached copy is found. * <p>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. * <p>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. <p>For example: <ul> * <li>'{@code /docs/cvs/commit.html}' and '{@code /docs/cvs/commit.html} -> ''</li> * <li>'{@code /docs/*}' and '{@code /docs/cvs/commit} -> '{@code cvs/commit}'</li> * <li>'{@code /docs/cvs/*.html}' and '{@code /docs/cvs/commit.html} -> '{@code commit.html}'</li> * <li>'{@code /docs/**}' and '{@code /docs/cvs/commit} -> '{@code cvs/commit}'</li> * <li>'{@code /docs/**\/*.html}' and '{@code /docs/cvs/commit.html} -> '{@code cvs/commit.html}'</li> * <li>'{@code /*.html}' and '{@code /docs/cvs/commit.html} -> '{@code docs/cvs/commit.html}'</li> * <li>'{@code *.html}' and '{@code /docs/cvs/commit.html} -> '{@code /docs/cvs/commit.html}'</li> * <li>'{@code *}' and '{@code /docs/cvs/commit.html} -> '{@code /docs/cvs/commit.html}'</li> </ul> * <p>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. * <p>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> </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/**</td><td>/bookings</td><td>/hotels/**/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/**</td><td>{hotel}</td><td>/hotels/**/{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. * <p>This{@code Comparator} will {@linkplain java.util.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: * <ol> * <li>{@code /hotels/new}</li> * <li>{@code /hotels/{hotel}}</li> <li>{@code /hotels/*}</li> * </ol> * the returned comparator will sort this list so that the order will be as indicated. * <p>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}. * <p>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 = "(.*)"; private final Pattern pattern; private final List<String> variableNames = new LinkedList<>(); public AntPathStringMatcher(String pattern) { this(pattern, true); } public AntPathStringMatcher(String pattern, boolean 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(); } patternBuilder.append(quote(pattern, end, pattern.length())); this.pattern = (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, @Nullable Map<String, String> uriTemplateVariables) { Matcher matcher = this.pattern.matcher(str); if (matcher.matches()) { if (uriTemplateVariables != null) { // SPR-8455 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); String value = matcher.group(i); uriTemplateVariables.put(name, value); } } return true; } else { return false; } } } /** * The default {@link Comparator} implementation returned by * {@link #getPatternComparator(String)}. * <p>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 { @Nullable private final String pattern; private int uriVars; private int singleWildcards; private int doubleWildcards; private boolean catchAllPattern; private boolean prefixPattern; @Nullable private Integer length; public PatternInfo(@Nullable 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; } } }