com.qualogy.qafe.bind.core.pattern.WildCardPattern.java Source code

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Here is the source code for com.qualogy.qafe.bind.core.pattern.WildCardPattern.java

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/**
 * Copyright 2008-2015 Qualogy Solutions B.V.
 *
 * 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.qualogy.qafe.bind.core.pattern;

import java.io.Serializable;
import java.util.regex.Pattern;

import org.apache.commons.lang.StringUtils;

/**
 * a pattern is a string to which a field, like an id can be applied to.
 * a pattern can be wildcarded. 
 * patterns:
 *    - *
 *  - *a
 *  - a*
 *  - aa
 *  not supported:
 *  - a*a
 *
 */

public class WildCardPattern implements Comparable<WildCardPattern>, Serializable {

    private static final long serialVersionUID = -7093827130572562410L;

    protected String pattern;

    /**
     * fields for optimalization reasons
     */
    private String regex;
    private String strippedPattern;

    public final static char WILDCARD = '*';

    public WildCardPattern() {
        super();
    }

    public WildCardPattern(String pattern) {
        super();
        this.pattern = pattern;
    }

    public boolean isWildCarded() {
        return isWildCardedAtTheBegin() || isWildCardedAtTheEnd();
    }

    public String toString() {
        return pattern;
    }

    public String stripWildCards() {
        if (strippedPattern == null)
            strippedPattern = StringUtils.strip(pattern, "" + WILDCARD);
        return strippedPattern;
    }

    private boolean isWildCardedAtPosition(int position) {
        return pattern.charAt(position) == WILDCARD;
    }

    public boolean isWildCardedAtTheBegin() {
        return isWildCardedAtPosition(0);
    }

    public boolean isWildCardedAtTheEnd() {
        return isWildCardedAtPosition(pattern.length() - 1);
    }

    public boolean matches(String toMatch) {
        return Pattern.matches(toRegex(), toMatch);
    }

    private String toRegex() {
        if (regex == null)
            regex = createRegex(pattern);
        return regex;
    }

    private String createRegex(String wildcard) {
        StringBuffer s = new StringBuffer(wildcard.length());

        s.append('^');
        for (int i = 0, is = wildcard.length(); i < is; i++) {
            char c = wildcard.charAt(i);
            switch (c) {
            case '*':
                s.append(".*");
                break;
            case '?':
                s.append(".");
                break;
            // escape special regexp-characters
            case '(':
            case ')':
            case '[':
            case ']':
            case '$':
            case '^':
            case '.':
            case '{':
            case '}':
            case '|':
            case '\\':
                s.append("\\");
                s.append(c);
                break;
            default:
                s.append(c);
                break;
            }
        }
        s.append('$');
        return (s.toString());
    }

    public int compareTo(WildCardPattern other) {
        int outcome = 0;

        if (this.stripWildCards().length() == 0)
            outcome = 1;
        else if (((WildCardPattern) other).stripWildCards().length() == 0)
            outcome = -1;
        else if (this.isWildCarded() && !((WildCardPattern) other).isWildCarded())
            outcome = 1;
        else if (!this.isWildCarded() && ((WildCardPattern) other).isWildCarded())
            outcome = -1;
        else if (this.isWildCarded() && ((WildCardPattern) other).isWildCarded()) {
            if (this.stripWildCards().length() > ((WildCardPattern) other).stripWildCards().length())
                outcome = -1;
            else
                outcome = 1;
        }
        return outcome;
    }
}