org.yasmin.core.config.parser.KeyValueToken.java Source code

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Here is the source code for org.yasmin.core.config.parser.KeyValueToken.java

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/*
 * Copyright (c) 2014 Frederico Campos & Massimiliano Ziccardi
 *
 * 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 org.yasmin.core.config.parser;

import org.apache.commons.lang3.StringUtils;

/**
 * This class represent a key/value pair. As per Yasmin documentatio, key value
 * pairs must start at the first column, without any leading space.
 * 
 * @author Massimiliano Ziccardi
 */
class KeyValueToken extends ConfigTokenBase {

    /**
     * Regex used to validate key name.
     */
    private final static String KEY_REGEX = "[a-zA-Z]{1}[a-zA-Z0-9_-]*";

    /**
     * The key name.
     */
    private String key;

    /**
     * The key value.
     */
    private String value;

    /**
     * Initializes the object with an empty line. Used only by the
     * {@link TokenFactory} object.
     */
    KeyValueToken() {
        super();
    }

    /**
     * Initializes the token with the given line.
     * 
     * @param line
     *            the line to be parsed
     */
    private KeyValueToken(String line) {
        super(line);
        init(line);
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.yasmin.core.config.parser.IYasminConfigToken#getType()
     */
    @Override
    public ConfigTokenType getType() {
        return ConfigTokenType.kvpair;
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * org.yasmin.core.config.parser.IYasminConfigToken#parse(java.lang.String)
     */
    @Override
    public IYasminConfigToken parse(String line) {
        if (!isValid(line)) {
            return null;
        }
        return new KeyValueToken(line);
    }

    /**
     * Checks if the given line is a valid keypair line.
     * 
     * @param line
     *            The line to be verified
     * @return <code>true</code> if the line is a valid keypair line.
     */
    private boolean isValid(String line) {
        if (!Character.isAlphabetic(line.charAt(0))) {
            return false;
        }

        // Line must not end with {
        if (StringUtils.strip(line).endsWith("{")) {
            return false;
        }

        int equalIndex = line.indexOf("=");
        // Starts with a character... it must have an equal sign...
        if (equalIndex == -1) {
            return false;
        }

        // Equal sign found... Let's validate the key...
        String keyName = line.substring(0, equalIndex);
        if (!keyName.matches(KEY_REGEX)) {
            return false;
        }

        return true;
    }

    /**
     * Extracts keyname and value from the line.
     * 
     * @param line
     *            the raw line
     */
    private void init(String line) {
        int equalIndex = line.indexOf("=");
        key = line.substring(0, equalIndex);
        value = line.substring(equalIndex + 1);
    }

    /**
     * @return the key name
     */
    public String getKey() {
        return key;
    }

    /**
     * @return the value
     */
    public String getValue() {
        return value;
    }
}