Shiro -Ant 风格的匹配URL的实现源码,以及Ant风格

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; } }

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