AntPathMatcher.java

package vnet.sms.common.shell.springshell.internal.ant;

import java.util.LinkedHashMap;
import java.util.Map;

import vnet.sms.common.shell.springshell.internal.util.Assert;
import vnet.sms.common.shell.springshell.internal.util.StringUtils;

/**
 * PathMatcher implementation for Ant-style path patterns. Examples are provided
 * below.
 * 
 * @author Alef Arendsen
 * @author Juergen Hoeller
 * @author Rob Harrop
 * @since 16.07.2003
 */
public class AntPathMatcher implements PathMatcher {

	/** 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(final String pathSeparator) {
		this.pathSeparator = (pathSeparator != null ? pathSeparator
		        : DEFAULT_PATH_SEPARATOR);
	}

	@Override
	public boolean isPattern(final String path) {
		return ((path.indexOf('*') != -1) || (path.indexOf('?') != -1));
	}

	@Override
	public boolean match(final String pattern, final String path) {
		return doMatch(pattern, path, true, null);
	}

	@Override
	public boolean matchStart(final String pattern, final String path) {
		return doMatch(pattern, path, false, null);
	}

	/**
	 * Actually match the given <code>path</code> against the given
	 * <code>pattern</code>.
	 * 
	 * @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 <code>true</code> if the supplied <code>path</code> matched,
	 *         <code>false</code> if it didn't
	 */
	protected boolean doMatch(final String pattern, final String path,
	        final boolean fullMatch,
	        final Map<String, String> uriTemplateVariables) {
		if (path.startsWith(this.pathSeparator) != pattern
		        .startsWith(this.pathSeparator)) {
			return false;
		}

		final String[] pattDirs = StringUtils.tokenizeToStringArray(pattern,
		        this.pathSeparator);
		final 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)) {
			final String patDir = pattDirs[pattIdxStart];
			if ("**".equals(patDir)) {
				break;
			}
			if (!matchStrings(patDir, pathDirs[pathIdxStart],
			        uriTemplateVariables)) {
				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)) {
			final String patDir = pattDirs[pattIdxEnd];
			if (patDir.equals("**")) {
				break;
			}
			if (!matchStrings(patDir, pathDirs[pathIdxEnd],
			        uriTemplateVariables)) {
				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
			final int patLength = (patIdxTmp - pattIdxStart - 1);
			final int strLength = (pathIdxEnd - pathIdxStart + 1);
			int foundIdx = -1;

			strLoop: for (int i = 0; i <= strLength - patLength; i++) {
				for (int j = 0; j < patLength; j++) {
					final String subPat = pattDirs[pattIdxStart + j + 1];
					final String subStr = pathDirs[pathIdxStart + i + j];
					if (!matchStrings(subPat, subStr, uriTemplateVariables)) {
						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:<br>
	 * '*' means zero or more characters<br>
	 * '?' means one and only one character
	 * 
	 * @param pattern
	 *            pattern to match against. Must not be <code>null</code>.
	 * @param str
	 *            string which must be matched against the pattern. Must not be
	 *            <code>null</code>.
	 * @return <code>true</code> if the string matches against the pattern, or
	 *         <code>false</code> otherwise.
	 */
	private boolean matchStrings(final String pattern, final String str,
	        final Map<String, String> uriTemplateVariables) {
		final AntPatchStringMatcher matcher = new AntPatchStringMatcher(
		        pattern, str, uriTemplateVariables);
		return matcher.matchStrings();
	}

	/**
	 * Given a pattern and a full path, determine the pattern-mapped part.
	 * <p>
	 * For example:
	 * <ul>
	 * <li>'<code>/docs/cvs/commit.html</code>' and '
	 * <code>/docs/cvs/commit.html</code> -> ''</li>
	 * <li>'<code>/docs/*</code>' and '<code>/docs/cvs/commit</code> -> '
	 * <code>cvs/commit</code>'</li>
	 * <li>'<code>/docs/cvs/*.html</code>' and '
	 * <code>/docs/cvs/commit.html</code> -> '<code>commit.html</code>'</li>
	 * <li>'<code>/docs/**</code>' and '<code>/docs/cvs/commit</code> -> '
	 * <code>cvs/commit</code>'</li>
	 * <li>'<code>/docs/**\/*.html</code>' and '
	 * <code>/docs/cvs/commit.html</code> -> '<code>cvs/commit.html</code>'</li>
	 * <li>'<code>/*.html</code>' and '<code>/docs/cvs/commit.html</code> -> '
	 * <code>docs/cvs/commit.html</code>'</li>
	 * <li>'<code>*.html</code>' and '<code>/docs/cvs/commit.html</code> -> '
	 * <code>/docs/cvs/commit.html</code>'</li>
	 * <li>'<code>*</code>' and '<code>/docs/cvs/commit.html</code> -> '
	 * <code>/docs/cvs/commit.html</code>'</li>
	 * </ul>
	 * <p>
	 * Assumes that {@link #match} returns <code>true</code> for '
	 * <code>pattern</code>' and '<code>path</code>', but does
	 * <strong>not</strong> enforce this.
	 */
	@Override
	public String extractPathWithinPattern(final String pattern,
	        final String path) {
		final String[] patternParts = StringUtils.tokenizeToStringArray(
		        pattern, this.pathSeparator);
		final String[] pathParts = StringUtils.tokenizeToStringArray(path,
		        this.pathSeparator);

		final StringBuilder builder = new StringBuilder();

		// Add any path parts that have a wildcarded pattern part.
		int puts = 0;
		for (int i = 0; i < patternParts.length; i++) {
			final String patternPart = patternParts[i];
			if (((patternPart.indexOf('*') > -1) || (patternPart.indexOf('?') > -1))
			        && (pathParts.length >= i + 1)) {
				if ((puts > 0)
				        || ((i == 0) && !pattern.startsWith(this.pathSeparator))) {
					builder.append(this.pathSeparator);
				}
				builder.append(pathParts[i]);
				puts++;
			}
		}

		// Append any trailing path parts.
		for (int i = patternParts.length; i < pathParts.length; i++) {
			if ((puts > 0) || (i > 0)) {
				builder.append(this.pathSeparator);
			}
			builder.append(pathParts[i]);
		}

		return builder.toString();
	}

	@Override
	public Map<String, String> extractUriTemplateVariables(
	        final String pattern, final String path) {
		final Map<String, String> variables = new LinkedHashMap<String, String>();
		final boolean result = doMatch(pattern, path, true, variables);
		Assert.state(result, "Pattern \"" + pattern
		        + "\" is not a match for \"" + path + "\"");
		return variables;
	}
}