uripattern.java

来自「resetful样式的ws样例,一种面向资源的webservices服务」· Java 代码 · 共 226 行

/*
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
 * 
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License. You can obtain
 * a copy of the License at https://jersey.dev.java.net/CDDL+GPL.html
 * or jersey/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 * 
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 * Header, with the fields enclosed by brackets [] replaced by your own
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 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package com.sun.jersey.api.uri;

import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;


/**
 * A URI pattern for matching a URI against a regular expression
 * and returning capturing group values for any capturing groups present in
 * the expression.
 *
 * @author [e-mail]
 */
public class UriPattern {
    /**
     * The empty URI pattern that matches the null or empty URI path
     */
    public static final UriPattern EMPTY = new UriPattern();
    
    /**
     * The regular expression for matching URIs 
     * and obtaining capturing group values.
     */
    private final String regex;
    
    /**
     * The compiled regular expression of {@link #regex}
     */
    private final Pattern regexPattern;
    
    /**
     *  Construct an empty pattern.
     */
    private UriPattern() {
        this(null);
    }

    /**
     * Construct a new URI pattern.
     * 
     * @param regex the regular expression. If the expression is null or an
     *        empty string then the pattern will only match a null or empty
     *        URI path.
     * 
     * @throws {@link java.util.regex.PatternSyntaxException} if the specific
     *         regular expression could not be generated
     */
    public UriPattern(String regex) {
        if (regex == null || regex.length() == 0) {
            this.regex = "";
            this.regexPattern = null;
        } else {
            this.regex = regex;
            this.regexPattern = Pattern.compile(regex);
        }
    }

    /**
     * Get the regular expression.
     * 
     * @return the regular expression.
     */
    public final String getRegex() {
        return regex;
    }
    
    /**
     * Match a URI against the pattern.
     * <p>
     * If the URI matches against the pattern then the capturing group values
     * (if any) will be added to a list passed in as parameter.
     * 
     * @param uri the uri to match against the template.
     * @param groupValues the list to add the values of a pattern's 
     *        capturing groups if matching is successful. The values are added
     *        in the same order as the pattern's capturing groups. The list
     *        is cleared before values are added.
     * @return true if the URI matches the pattern, otherwise false.
     * @throws {@link IllegalArgumentException} if the uri or 
     *         capturingGroupValues is null.
     */
    public final boolean match(CharSequence uri, List<String> groupValues) {
        if (groupValues == null) 
            throw new IllegalArgumentException();

        // Check for match against the empty pattern
        if (uri == null || uri.length() == 0)
            return (regexPattern == null) ? true : false;
        else if (regexPattern == null)
            return false;
                
        // Match the URI to the URI template regular expression
        Matcher m = regexPattern.matcher(uri);
        if (!m.matches())
            return false;

        groupValues.clear();                
        for (int i = 1; i <= m.groupCount(); i++) {
            groupValues.add(m.group(i));
        }
        
        // TODO check for consistency of different capturing groups
        // that must have the same value
        
        return true;
    }
    
    /**
     * Match a URI against the pattern.
     * <p>
     * If the URI matches against the pattern then the capturing group values
     * (if any) will be added to a map passed in as parameter.
     * 
     * @param uri the uri to match against the template.
     * @param groupNames the list names associated with a pattern's 
     *        capturing groups. The names MUST be in the same order as the 
     *        pattern's capturing groups and the size MUST be equal to or
     *        less than the number of capturing groups.
     * @param groupValues the map to add the values of a pattern's 
     *        capturing groups if matching is successful. A values is put
     *        into the map using the group name associated with the 
     *        capturing group. The map is cleared before values are added.
     * @return true if the URI matches the pattern, otherwise false.
     * @throws {@link IllegalArgumentException} if the uri or 
     *         capturingGroupValues is null.
     */
    public final boolean match(CharSequence uri, 
            List<String> groupNames, Map<String, String> groupValues) {
        if (groupValues == null) 
            throw new IllegalArgumentException();

        // Check for match against the empty pattern
        if (uri == null || uri.length() == 0)
            return (regexPattern == null) ? true : false;
        else if (regexPattern == null)
            return false;
        
        // Match the URI to the URI template regular expression
        Matcher m = regexPattern.matcher(uri);
        if (!m.matches())
            return false;
        
        // Assign the matched group values to group names
        groupValues.clear();
        int i = 1;
        for (String name : groupNames) {
            String previousValue = groupValues.get(name);
            String currentValue = m.group(i++);
            
            // Group names can have the same name occuring more than once, 
            // check that groups values are same.
            if (previousValue != null && !previousValue.equals(currentValue))
                return false;
            
            groupValues.put(name, currentValue);
        }
        
        return true;
    }
    
    @Override
    public final int hashCode() {
        return regex.hashCode();
    }

    @Override
    public final boolean equals(Object obj) {
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        final UriPattern that = (UriPattern) obj;
        if (this.regex != that.regex && 
                (this.regex == null || !this.regex.equals(that.regex))) {
            return false;
        }
        return true;
    }
    
    @Override
    public final String toString() {
        return regex;
    }
}