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XWork is an command-pattern framework that is used to power WebWork as well as other applications. XWork provides an Inversion of Control container, a powerful expression language, data type conversion, validation, and pluggable configuration.

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/*
 * $Id: ActionConfigMatcher.java 1630 2007-10-05 15:10:08Z mrdon $
 *
 * Copyright 2003,2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.opensymphony.xwork2.config.impl;

import com.opensymphony.xwork2.util.PatternMatcher;
import com.opensymphony.xwork2.util.logging.Logger;
import com.opensymphony.xwork2.util.logging.LoggerFactory;

import java.io.Serializable;
import java.util.*;

/**
 * 
 Matches patterns against pre-compiled wildcard expressions pulled from
 * target objects. It uses the wildcard matcher from the Apache Cocoon
 * project. Patterns will be matched in the order they were added. The first 
 * match wins, so more specific patterns should be defined before less specific 
 * patterns.
 * 
 * @since 2.1
 */
public abstract class AbstractMatcher implements Serializable {
    /**
     * 
 The logging instance 

     */
    private static final Logger log = LoggerFactory.getLogger(AbstractMatcher.class);

    /**
     * 
 Handles all wildcard pattern matching. 

     */
    PatternMatcher wildcard;

    /**
     * 
 The compiled patterns and their associated target objects 

     */
    List> compiledPatterns = new ArrayList>();;
    
    public AbstractMatcher(PatternMatcher helper) {
        this.wildcard = (PatternMatcher) helper;
    }

    /**
     * 

     * Finds and precompiles the wildcard patterns. Patterns will be evaluated
     * in the order they were added. Only patterns that actually contain a
     * wildcard will be compiled.
     * 

     * 
     * 

     * Patterns can optionally be matched "loosely". When the end of the pattern
     * matches \*[^*]\*$ (wildcard, no wildcard, wildcard), if the pattern
     * fails, it is also matched as if the last two characters didn't exist. The
     * goal is to support the legacy "*!*" syntax, where the "!*" is optional.
     * 

     * 
     * @param name The pattern
     * @param target The object to associate with the pattern
     * @param looseMatch
     *            To loosely match wildcards or not
     */
    public void addPattern(String name, E target, boolean looseMatch) {

        Object pattern;

        if (!wildcard.isLiteral(name)) {
            if (looseMatch && (name.length() > 0) && (name.charAt(0) == '/')) {
                name = name.substring(1);
            }

            if (log.isDebugEnabled()) {
                log.debug("Compiling pattern '" + name + "'");
            }

            pattern = wildcard.compilePattern(name);
            compiledPatterns.add(new Mapping(name, pattern, target));

            if (looseMatch) {
                int lastStar = name.lastIndexOf('*');
                if (lastStar > 1 && lastStar == name.length() - 1) {
                    if (name.charAt(lastStar - 1) != '*') {
                        pattern = wildcard.compilePattern(name.substring(0, lastStar - 1));
                        compiledPatterns.add(new Mapping(name, pattern, target));
                    }
                }
            }
        }
    }
    
    public void freeze() {
        compiledPatterns = Collections.unmodifiableList(new ArrayList>());
    }

    /**
     * 
 Matches the path against the compiled wildcard patterns. 

     *
     * @param potentialMatch The portion of the request URI for selecting a config.
     * @return The action config if matched, else null
     */
    public E match(String potentialMatch) {
        E config = null;

        if (compiledPatterns.size() > 0) {
            if (log.isDebugEnabled()) {
                log.debug("Attempting to match '" + potentialMatch
                    + "' to a wildcard pattern, "+ compiledPatterns.size()
                    + " available");
            }

            Map vars = new LinkedHashMap();
            for (Mapping m : compiledPatterns) {
                if (wildcard.match(vars, potentialMatch, m.getPattern())) {
                    if (log.isDebugEnabled()) {
                        log.debug("Value matches pattern '"
                            + m.getOriginalPattern() + "'");
                    }

                    config =
                        convert(potentialMatch, m.getTarget(), vars);
                    break;
                }
            }
        }

        return config;
    }

    /**
     * 
 Clones the target object and its children, replacing various
     * properties with the values of the wildcard-matched strings. 

     *
     * @param path The requested path
     * @param orig The original object
     * @param vars A Map of wildcard-matched strings
     * @return A cloned object with appropriate properties replaced with
     *         wildcard-matched values
     */
    protected abstract E convert(String path, E orig, Map vars);

    /**
     * 
 Replaces parameter values
     * 

     *
     * @param orig  The original parameters with placehold values
     * @param vars  A Map of wildcard-matched strings
     */
    protected Map replaceParameters(Map orig, Map vars) {
        Map map = new LinkedHashMap();
        for (String key : orig.keySet()) {
            map.put(key, convertParam(orig.get(key), vars));
        }
        return map;
    }

    /**
     * 
 Inserts into a value wildcard-matched strings where specified
     * with the {x} syntax.  If a wildcard-matched value isn't found, the
     * replacement token is turned into an empty string. 
     * 

     *
     * @param val  The value to convert
     * @param vars A Map of wildcard-matched strings
     * @return The new value
     */
    protected String convertParam(String val, Map vars) {
        if (val == null) {
            return null;
        } 
        
        int len = val.length();
        StringBuilder ret = new StringBuilder();
        char c;
        String varVal;
        for (int x=0; x Stores a compiled wildcard pattern and the object it came
     * from. 

     */
    private static class Mapping implements Serializable {
        /**
         * 
 The original pattern. 

         */
        private String original;

        
        /**
         * 
 The compiled pattern. 

         */
        private Object pattern;

        /**
         * 
 The original object. 

         */
        private E config;

        /**
         * 
 Contructs a read-only Mapping instance. 

         *
         * @param original The original pattern
         * @param pattern The compiled pattern
         * @param config  The original object
         */
        public Mapping(String original, Object pattern, E config) {
            this.original = original;
            this.pattern = pattern;
            this.config = config;
        }

        /**
         * 
 Gets the compiled wildcard pattern. 

         *
         * @return The compiled pattern
         */
        public Object getPattern() {
            return this.pattern;
        }

        /**
         * 
 Gets the object that contains the pattern. 

         *
         * @return The associated object
         */
        public E getTarget() {
            return this.config;
        }
        
        /**
         * 
 Gets the original wildcard pattern. 

         *
         * @return The original pattern
         */
        public String getOriginalPattern() {
            return this.original;
        }
    }
}
    

    

    

            

    

            



    
    






    
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