什么是Ant风格的匹配模式
这种风格的模式,其实我们使用的非常多的,Spring中设置扫描路径需要配置吧!这里的实现为AntPathMatcher,借用了Spring的,昨天我们在PathMatchingFilterChainResolver中的哦,匹配器。
PathMatcher implementation for Ant-style path patterns.
The mapping matches URLs using the following rules
? matches one character 一个字符
* matches zero or more characters 0个或多个字符
** matches zero or more 'directories' in a path 0个或多个子目录 这个需要懂吧
这个实现的实现挺好的,不过实现起来挺麻烦的,使用字符串“/”拆分,然后在将当前的字符串进行比较拆分为字符,在进行比较,不过这里有很多的情况,实现起来考虑的东西比较的多,特殊性所在。
URL路径 说明
/app/*.x 匹配(Matches)所有在app路径下的.x文件
/app/p?ttern 匹配(Matches) /app/pattern 和 /app/pXttern,但是不包括/app/pttern
/**/example 匹配(Matches) /app/example, /app/foo/example, 和 /example
/app/**/dir/file. 匹配(Matches) /app/dir/file.jsp, /app/foo/dir/file.html,/app/foo/bar/dir/file.pdf, 和 /app/dir/file.java
/**/*.jsp 匹配(Matches)任何的.jsp 文件
这段代码还是比较的复杂的,考虑的情况各种各样!
public class AntPathMatcher implements PatternMatcher {
//TODO - complete JavaDoc
/**
* Default path separator: "/"
*/
public static final String DEFAULT_PATH_SEPARATOR = "/";
private String pathSeparator = DEFAULT_PATH_SEPARATOR;
/**
* 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);
}
public boolean isPattern(String path) {
return (path.indexOf('*') != -1 || path.indexOf('?') != -1);
}
public boolean matches(String pattern, String source) {
return match(pattern, source);
}
public boolean match(String pattern, String path) {
return doMatch(pattern, path, true);
}
public boolean matchStart(String pattern, String path) {
return doMatch(pattern, path, false);
}
/**
* Actually match the given path
against the given pattern
.
*
* @param pattern the pattern to match against
* @param path the path String 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 true
if the supplied path
matched,
* false
if it didn't
*/
protected boolean doMatch(String pattern, String path, boolean fullMatch) {
if (path.startsWith(this.pathSeparator) != pattern.startsWith(this.pathSeparator)) {
return false;
}
String[] pattDirs = StringUtils.tokenizeToStringArray(pattern, this.pathSeparator);
String[] pathDirs = StringUtils.tokenizeToStringArray(path, this.pathSeparator);
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 patDir = pattDirs[pattIdxStart];
if ("**".equals(patDir)) {
break;
}
if (!matchStrings(patDir, pathDirs[pathIdxStart])) {
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) : !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 patDir = pattDirs[pattIdxEnd];
if (patDir.equals("**")) {
break;
}
if (!matchStrings(patDir, pathDirs[pathIdxEnd])) {
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 = (String) pattDirs[pattIdxStart + j + 1];
String subStr = (String) pathDirs[pathIdxStart + i + j];
if (!matchStrings(subPat, subStr)) {
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;
}
/**
* Tests whether or not a string matches against a pattern.
* The pattern may contain two special characters:
* '*' means zero or more characters
* '?' means one and only one character
*
* @param pattern pattern to match against.
* Must not be null
.
* @param str string which must be matched against the pattern.
* Must not be null
.
* @return true
if the string matches against the
* pattern, or false
otherwise.
*/
private boolean matchStrings(String pattern, String str) {
char[] patArr = pattern.toCharArray();
char[] strArr = str.toCharArray();
int patIdxStart = 0;
int patIdxEnd = patArr.length - 1;
int strIdxStart = 0;
int strIdxEnd = strArr.length - 1;
char ch;
boolean containsStar = false;
for (char aPatArr : patArr) {
if (aPatArr == '*') {
containsStar = true;
break;
}
}
if (!containsStar) {
// No '*'s, so we make a shortcut
if (patIdxEnd != strIdxEnd) {
return false; // Pattern and string do not have the same size
}
for (int i = 0; i <= patIdxEnd; i++) {
ch = patArr[i];
if (ch != '?') {
if (ch != strArr[i]) {
return false;// Character mismatch
}
}
}
return true; // String matches against pattern
}
if (patIdxEnd == 0) {
return true; // Pattern contains only '*', which matches anything
}
// Process characters before first star 先找到不是*的位置开始,进行原始的比较
while ((ch = patArr[patIdxStart]) != '*' && strIdxStart <= strIdxEnd) {
if (ch != '?') {
if (ch != strArr[strIdxStart]) {
return false;// Character mismatch
}
}
patIdxStart++;
strIdxStart++;
}
if (strIdxStart > strIdxEnd) {
// All characters in the string are used. Check if only '*'s are
// left in the pattern. If so, we succeeded. Otherwise failure.
for (int i = patIdxStart; i <= patIdxEnd; i++) {
if (patArr[i] != '*') {
return false;
}
}
return true;
}
// Process characters after last star
while ((ch = patArr[patIdxEnd]) != '*' && strIdxStart <= strIdxEnd) {
if (ch != '?') {
if (ch != strArr[strIdxEnd]) {
return false;// Character mismatch
}
}
patIdxEnd--;
strIdxEnd--;
}
if (strIdxStart > strIdxEnd) {
// All characters in the string are used. Check if only '*'s are
// left in the pattern. If so, we succeeded. Otherwise failure.
for (int i = patIdxStart; i <= patIdxEnd; i++) {
if (patArr[i] != '*') {
return false;
}
}
return true;
}
// process pattern between stars. padIdxStart and patIdxEnd point
// always to a '*'.
while (patIdxStart != patIdxEnd && strIdxStart <= strIdxEnd) {
int patIdxTmp = -1;
for (int i = patIdxStart + 1; i <= patIdxEnd; i++) {
if (patArr[i] == '*') {
patIdxTmp = i;
break;
}
}
if (patIdxTmp == patIdxStart + 1) {
// Two stars next to each other, skip the first one.
patIdxStart++;
continue;
}
// Find the pattern between padIdxStart & padIdxTmp in str between
// strIdxStart & strIdxEnd
int patLength = (patIdxTmp - patIdxStart - 1);
int strLength = (strIdxEnd - strIdxStart + 1);
int foundIdx = -1;
strLoop:
for (int i = 0; i <= strLength - patLength; i++) {
for (int j = 0; j < patLength; j++) {
ch = patArr[patIdxStart + j + 1];
if (ch != '?') {
if (ch != strArr[strIdxStart + i + j]) {
continue strLoop;
}
}
}
foundIdx = strIdxStart + i;
break;
}
if (foundIdx == -1) {
return false;
}
patIdxStart = patIdxTmp;
strIdxStart = foundIdx + patLength;
}
// All characters in the string are used. Check if only '*'s are left
// in the pattern. If so, we succeeded. Otherwise failure.
for (int i = patIdxStart; i <= patIdxEnd; i++) {
if (patArr[i] != '*') {
return false;
}
}
return true;
}
}