Spring AntPathMatcher
AntPathMatcher是用来对资源路径或者url的字符串做匹配使用的。采用的是Ant风格的格式
Ant风格的资源地址支持3中匹配
- ？：匹配文件名中的一个字符
- *：匹配文件中的任意字符
- ：匹配多层路径 如下示例： classpath:com/con?.xml:匹配com路径下的com/conf.xml、com/cont.xml等文件 classpath:com/*.xml:匹配com路径下的所有的xml文件 classpath:com//a.xml：匹配com路径下其他文件夹下的所有的a.xml文件
AntPathMatcher的主要属性如下：
//默认路径分隔符
public static final String DEFAULT_PATH_SEPARATOR = "/";
private static final int CACHE_TURNOFF_THRESHOLD = 65536;
//正则表达式
private static final Pattern VARIABLE_PATTERN = Pattern.compile("\\{[^/]+?}");
//通配符
private static final char[] WILDCARD_CHARS = { '*', '?', '{' };
private String pathSeparator;
private PathSeparatorPatternCache pathSeparatorPatternCache;
private boolean caseSensitive = true;
//默认不
private boolean trimTokens = false;
//用来定义是否缓存分词
@Nullable
private volatile Boolean cachePatterns;
//用来缓存规则的分词
private final Map tokenizedPatternCache = new ConcurrentHashMap<>(256);
final Map stringMatcherCache = new ConcurrentHashMap<>(256);
其中Spring中用到最多的方法就是match()方法啦，
//用来匹配路径字符串是否满足给定的规则
@Override
public boolean match(String pattern, String path) {
return doMatch(pattern, path, true, null);
}
protected boolean doMatch(String pattern, @Nullable String path, boolean fullMatch,
@Nullable Map uriTemplateVariables) {
//判断path是null 或者pattern和path的首字符是否同时为设置的分隔符，如果为null或者不一致则直接返回false
if (path == null || path.startsWith(this.pathSeparator) != pattern.startsWith(this.pathSeparator)) {
return false;
}
//对规则进行分词
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 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) {
// 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 pathIdxEnd) {
// String is exhausted
for (int i = pattIdxStart; i
对规则进行分词
//对规则进行分词
protected String[] tokenizePattern(String pattern) {
String[] tokenized = null;
Boolean cachePatterns = this.cachePatterns;
//当cachePatterns为null或者为true时，表示缓存分词，需要首先从map对象中获取
if (cachePatterns == null || cachePatterns.booleanValue()) {
//从缓存中获取分词
tokenized = this.tokenizedPatternCache.get(pattern);
}
//缓存中不存在该分词是
if (tokenized == null) {
tokenized = tokenizePath(pattern);
//当cachePatterns为null且tokenizedPatternCache对象中缓存的对象大于等于65536时,将缓存对象清空
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.
//缓存对象清空
deactivatePatternCache();
return tokenized;
}
//将分词放入缓存中
if (cachePatterns == null || cachePatterns.booleanValue()) {
this.tokenizedPatternCache.put(pattern, tokenized);
}
}
return tokenized;
}
//匹配字符串path是否以pattern开头
@Override
public boolean matchStart(String pattern, String path) {
return doMatch(pattern, path, false, null);
}
Original: https://www.cnblogs.com/haizhilangzi/p/12805150.html
Author: 海之浪子
Title: Spring AntPathMatcher
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