/*
* Copyright 2002-2014 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
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.web.servlet.mvc.condition;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;
import javax.servlet.http.HttpServletRequest;
import org.springframework.util.AntPathMatcher;
import org.springframework.util.PathMatcher;
import org.springframework.util.StringUtils;
import org.springframework.web.util.UrlPathHelper;
/**
* A logical disjunction (' || ') request condition that matches a request
* against a set of URL path patterns.
*
* @author Rossen Stoyanchev
* @since 3.1
*/
public final class PatternsRequestCondition extends AbstractRequestCondition<PatternsRequestCondition> {
private final Set<String> patterns;
private final UrlPathHelper pathHelper;
private final PathMatcher pathMatcher;
private final boolean useSuffixPatternMatch;
private final boolean useTrailingSlashMatch;
private final List<String> fileExtensions = new ArrayList<String>();
/**
* Creates a new instance with the given URL patterns.
* Each pattern that is not empty and does not start with "/" is prepended with "/".
* @param patterns 0 or more URL patterns; if 0 the condition will match to every request.
*/
public PatternsRequestCondition(String... patterns) {
this(asList(patterns), null, null, true, true, null);
}
/**
* Additional constructor with flags for using suffix pattern (.*) and
* trailing slash matches.
* @param patterns the URL patterns to use; if 0, the condition will match to every request.
* @param urlPathHelper for determining the lookup path of a request
* @param pathMatcher for path matching with patterns
* @param useSuffixPatternMatch whether to enable matching by suffix (".*")
* @param useTrailingSlashMatch whether to match irrespective of a trailing slash
*/
public PatternsRequestCondition(String[] patterns, UrlPathHelper urlPathHelper, PathMatcher pathMatcher,
boolean useSuffixPatternMatch, boolean useTrailingSlashMatch) {
this(asList(patterns), urlPathHelper, pathMatcher, useSuffixPatternMatch, useTrailingSlashMatch, null);
}
/**
* Creates a new instance with the given URL patterns.
* Each pattern that is not empty and does not start with "/" is pre-pended with "/".
* @param patterns the URL patterns to use; if 0, the condition will match to every request.
* @param urlPathHelper a {@link UrlPathHelper} for determining the lookup path for a request
* @param pathMatcher a {@link PathMatcher} for pattern path matching
* @param useSuffixPatternMatch whether to enable matching by suffix (".*")
* @param useTrailingSlashMatch whether to match irrespective of a trailing slash
* @param fileExtensions a list of file extensions to consider for path matching
*/
public PatternsRequestCondition(String[] patterns, UrlPathHelper urlPathHelper,
PathMatcher pathMatcher, boolean useSuffixPatternMatch, boolean useTrailingSlashMatch,
List<String> fileExtensions) {
this(asList(patterns), urlPathHelper, pathMatcher, useSuffixPatternMatch, useTrailingSlashMatch, fileExtensions);
}
/**
* Private constructor accepting a collection of patterns.
*/
private PatternsRequestCondition(Collection<String> patterns, UrlPathHelper urlPathHelper,
PathMatcher pathMatcher, boolean useSuffixPatternMatch, boolean useTrailingSlashMatch,
List<String> fileExtensions) {
this.patterns = Collections.unmodifiableSet(prependLeadingSlash(patterns));
this.pathHelper = urlPathHelper != null ? urlPathHelper : new UrlPathHelper();
this.pathMatcher = pathMatcher != null ? pathMatcher : new AntPathMatcher();
this.useSuffixPatternMatch = useSuffixPatternMatch;
this.useTrailingSlashMatch = useTrailingSlashMatch;
if (fileExtensions != null) {
for (String fileExtension : fileExtensions) {
if (fileExtension.charAt(0) != '.') {
fileExtension = "." + fileExtension;
}
this.fileExtensions.add(fileExtension);
}
}
}
private static List<String> asList(String... patterns) {
return (patterns != null ? Arrays.asList(patterns) : Collections.<String>emptyList());
}
private static Set<String> prependLeadingSlash(Collection<String> patterns) {
if (patterns == null) {
return Collections.emptySet();
}
Set<String> result = new LinkedHashSet<String>(patterns.size());
for (String pattern : patterns) {
if (StringUtils.hasLength(pattern) && !pattern.startsWith("/")) {
pattern = "/" + pattern;
}
result.add(pattern);
}
return result;
}
public Set<String> getPatterns() {
return this.patterns;
}
@Override
protected Collection<String> getContent() {
return this.patterns;
}
@Override
protected String getToStringInfix() {
return " || ";
}
/**
* Returns a new instance with URL patterns from the current instance ("this") and
* the "other" instance as follows:
* <ul>
* <li>If there are patterns in both instances, combine the patterns in "this" with
* the patterns in "other" using {@link PathMatcher#combine(String, String)}.
* <li>If only one instance has patterns, use them.
* <li>If neither instance has patterns, use an empty String (i.e. "").
* </ul>
*/
@Override
public PatternsRequestCondition combine(PatternsRequestCondition other) {
Set<String> result = new LinkedHashSet<String>();
if (!this.patterns.isEmpty() && !other.patterns.isEmpty()) {
for (String pattern1 : this.patterns) {
for (String pattern2 : other.patterns) {
result.add(this.pathMatcher.combine(pattern1, pattern2));
}
}
}
else if (!this.patterns.isEmpty()) {
result.addAll(this.patterns);
}
else if (!other.patterns.isEmpty()) {
result.addAll(other.patterns);
}
else {
result.add("");
}
return new PatternsRequestCondition(result, this.pathHelper, this.pathMatcher, this.useSuffixPatternMatch,
this.useTrailingSlashMatch, this.fileExtensions);
}
/**
* Checks if any of the patterns match the given request and returns an instance
* that is guaranteed to contain matching patterns, sorted via
* {@link PathMatcher#getPatternComparator(String)}.
* <p>A matching pattern is obtained by making checks in the following order:
* <ul>
* <li>Direct match
* <li>Pattern match with ".*" appended if the pattern doesn't already contain a "."
* <li>Pattern match
* <li>Pattern match with "/" appended if the pattern doesn't already end in "/"
* </ul>
* @param request the current request
* @return the same instance if the condition contains no patterns;
* or a new condition with sorted matching patterns;
* or {@code null} if no patterns match.
*/
@Override
public PatternsRequestCondition getMatchingCondition(HttpServletRequest request) {
if (this.patterns.isEmpty()) {
return this;
}
String lookupPath = this.pathHelper.getLookupPathForRequest(request);
List<String> matches = getMatchingPatterns(lookupPath);
return matches.isEmpty() ? null :
new PatternsRequestCondition(matches, this.pathHelper, this.pathMatcher, this.useSuffixPatternMatch,
this.useTrailingSlashMatch, this.fileExtensions);
}
/**
* Find the patterns matching the given lookup path. Invoking this method should
* yield results equivalent to those of calling
* {@link #getMatchingCondition(javax.servlet.http.HttpServletRequest)}.
* This method is provided as an alternative to be used if no request is available
* (e.g. introspection, tooling, etc).
*
* @param lookupPath the lookup path to match to existing patterns
* @return a collection of matching patterns sorted with the closest match at the top
*/
public List<String> getMatchingPatterns(String lookupPath) {
List<String> matches = new ArrayList<String>();
for (String pattern : this.patterns) {
String match = getMatchingPattern(pattern, lookupPath);
if (match != null) {
matches.add(match);
}
}
Collections.sort(matches, this.pathMatcher.getPatternComparator(lookupPath));
return matches;
}
private String getMatchingPattern(String pattern, String lookupPath) {
if (pattern.equals(lookupPath)) {
return pattern;
}
if (this.useSuffixPatternMatch) {
if (!this.fileExtensions.isEmpty() && lookupPath.indexOf('.') != -1) {
for (String extension : this.fileExtensions) {
if (this.pathMatcher.match(pattern + extension, lookupPath)) {
return pattern + extension;
}
}
}
else {
boolean hasSuffix = pattern.indexOf('.') != -1;
if (!hasSuffix && this.pathMatcher.match(pattern + ".*", lookupPath)) {
return pattern + ".*";
}
}
}
if (this.pathMatcher.match(pattern, lookupPath)) {
return pattern;
}
if (this.useTrailingSlashMatch) {
if (!pattern.endsWith("/") && this.pathMatcher.match(pattern + "/", lookupPath)) {
return pattern +"/";
}
}
return null;
}
/**
* Compare the two conditions based on the URL patterns they contain.
* Patterns are compared one at a time, from top to bottom via
* {@link PathMatcher#getPatternComparator(String)}. If all compared
* patterns match equally, but one instance has more patterns, it is
* considered a closer match.
* <p>It is assumed that both instances have been obtained via
* {@link #getMatchingCondition(HttpServletRequest)} to ensure they
* contain only patterns that match the request and are sorted with
* the best matches on top.
*/
@Override
public int compareTo(PatternsRequestCondition other, HttpServletRequest request) {
String lookupPath = this.pathHelper.getLookupPathForRequest(request);
Comparator<String> patternComparator = this.pathMatcher.getPatternComparator(lookupPath);
Iterator<String> iterator = this.patterns.iterator();
Iterator<String> iteratorOther = other.patterns.iterator();
while (iterator.hasNext() && iteratorOther.hasNext()) {
int result = patternComparator.compare(iterator.next(), iteratorOther.next());
if (result != 0) {
return result;
}
}
if (iterator.hasNext()) {
return -1;
}
else if (iteratorOther.hasNext()) {
return 1;
}
else {
return 0;
}
}
}