ant path匹配

spring和ant path实现相关的主要类有两个
org.springframework.util.PathMatcher
org.springframework.util.AntPathMatcher.AntPatternComparator.AntPatternComparator

可以看下springmvc的通过url查找action的方法

Object org.springframework.web.servlet.handler.AbstractUrlHandlerMapping.getHandlerInternal(HttpServletRequest request) throws Exception

，这个方法的前面两行代码：
String lookupPath = this.urlPathHelper.getLookupPathForRequest(request);
Object handler = lookupHandler(lookupPath, request);

再看lookupHandler
Object org.springframework.web.servlet.handler.AbstractUrlHandlerMapping.lookupHandler(String urlPath, HttpServletRequest request) throws Exception



// 这里是绝对匹配，如我们的RequestMapping("/getView")，那么请求/test/getView，这种资源是可以绝对匹配上的，那么直接get就可以了。

Object handler = this.handlerMap.get(urlPath);
if (handler != null) {
// Bean name or resolved handler?
if (handler instanceof String) {
String handlerName = (String) handler;
handler = getApplicationContext().getBean(handlerName);
}
validateHandler(handler, request);
return buildPathExposingHandler(handler, urlPath, urlPath, null);
}

// 这里就是通过ant的方式，查找符合ant的匹配资源列表
List<String> matchingPatterns = new ArrayList<String>();
for (String registeredPattern : this.handlerMap.keySet()) {
if (getPathMatcher().match(registeredPattern, urlPath)) {
matchingPatterns.add(registeredPattern);
}
}

//当列表不为空，表示查找到符合的列表，然后按照ant规则，排序，越精确的越靠前
String bestPatternMatch = null;
Comparator<String> patternComparator = getPathMatcher().getPatternComparator(urlPath);
if (!matchingPatterns.isEmpty()) {
Collections.sort(matchingPatterns, patternComparator);
if (logger.isDebugEnabled()) {
logger.debug("Matching patterns for request [" + urlPath + "] are " + matchingPatterns);
}
bestPatternMatch = matchingPatterns.get(0);
}
if (bestPatternMatch != null) {
handler = this.handlerMap.get(bestPatternMatch);
// Bean name or resolved handler?
if (handler instanceof String) {
String handlerName = (String) handler;
handler = getApplicationContext().getBean(handlerName);
}
validateHandler(handler, request);
String pathWithinMapping = getPathMatcher().extractPathWithinPattern(bestPatternMatch, urlPath);

// There might be multiple 'best patterns', let's make sure we have the correct URI template variables
// for all of them
Map<String, String> uriTemplateVariables = new LinkedHashMap<String, String>();
for (String matchingPattern : matchingPatterns) {
if (patternComparator.compare(bestPatternMatch, matchingPattern) == 0) {
uriTemplateVariables
.putAll(getPathMatcher().extractUriTemplateVariables(matchingPattern, urlPath));
}
}
if (logger.isDebugEnabled()) {
logger.debug("URI Template variables for request [" + urlPath + "] are " + uriTemplateVariables);
}
return buildPathExposingHandler(handler, bestPatternMatch, pathWithinMapping, uriTemplateVariables);
}
// No handler found...
return null;
}