com.bazaarvoice.jolt.common.pathelement.StarSinglePathElement.java Source code

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Here is the source code for com.bazaarvoice.jolt.common.pathelement.StarSinglePathElement.java

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/*
 * Copyright 2013 Bazaarvoice, Inc.
 *
 * 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.bazaarvoice.jolt.common.pathelement;

import com.bazaarvoice.jolt.common.WalkedPath;
import org.apache.commons.lang.StringUtils;

import java.util.ArrayList;
import java.util.List;

/**
 * PathElement for the a single "*" wildcard.   In this case we can avoid doing any
 *  regex work by doing String begins and ends with comparisons.
 */
public class StarSinglePathElement extends BasePathElement implements StarPathElement {

    private final String prefix, suffix;

    public StarSinglePathElement(String key) {
        super(key);

        if (StringUtils.countMatches(key, "*") != 1) {
            throw new IllegalArgumentException("StarSinglePathElement should only have one '*' in its key.");
        } else if ("*".equals(key)) {
            throw new IllegalArgumentException("StarSinglePathElement should have a key that is just '*'.");
        }

        if (key.startsWith("*")) {
            prefix = "";
            suffix = key.substring(1);
        } else if (key.endsWith("*")) {
            prefix = key.substring(0, key.length() - 1);
            suffix = "";
        } else {
            String[] split = key.split("\\*");
            prefix = split[0];
            suffix = split[1];
        }
    }

    /**
     * @param literal test to see if the provided string will match this Element's regex
     * @return true if the provided literal will match this Element's regex
     */
    @Override
    public boolean stringMatch(String literal) {
        return literal.startsWith(prefix) && literal.endsWith(suffix) // the ends match
                && literal.length() > prefix.length() + suffix.length(); // and the * captures something
    }

    @Override
    public LiteralPathElement match(String dataKey, WalkedPath walkedPath) {

        if (stringMatch(dataKey)) {
            List<String> subKeys = new ArrayList<String>(1);

            String starPart = dataKey.substring(prefix.length(), dataKey.length() - suffix.length());
            subKeys.add(starPart);

            return new LiteralPathElement(dataKey, subKeys);
        }

        return null;
    }

    @Override
    public String getCanonicalForm() {
        return getRawKey();
    }
}