hr.fer.spocc.util.BasePropertyConstants.java Source code

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Here is the source code for hr.fer.spocc.util.BasePropertyConstants.java

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/*
 * BasePropertyConstants.java
 *
 * Copyright (C) 2010 Leo Osvald <leo.osvald@gmail.com>
 *
 * This file is part of SPoCC.
 *
 * SPoCC is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * SPoCC is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with SPoCC. If not, see <http://www.gnu.org/licenses/>.
 */
package hr.fer.spocc.util;

import org.apache.commons.lang.StringUtils;
import org.sglj.util.StringBuilderUtils;

/**
 * Base class for holding property constants.
 * Property names should conform to the following rules:
 * <ul>
 * <li>must not be an empty or <code>null</code> string</li>
 * <li>must not contain whitespace characters</li>
 * <li>must not contain the equals sign ('=')</li>
 * <li>if consist of several parts, all parts must be separated by
 * {@link #SEPARATOR}</li>
 * </ul>
 * 
 * @author Leo Osvald
 * @version 1.0
 */
public abstract class BasePropertyConstants {

    protected static final String SEPARATOR = ".";

    /**
     * Return the property name based on the specified prefix.
     * For example, if the prefix is "some.example." or "some.example", 
     * "some.example" will be returned. 
     * 
     * @param prefix the prefix
     * @return property name
     */
    protected static String prefixToPropertyName(String prefix) {
        return StringUtils.substringBeforeLast(prefix, SEPARATOR);
    }

    /**
     * Returns the relative name of the property; for example, relative
     * name of the "some.example" is "example", but relative name
     * of the "test" is again "test".
     * 
     * @param propertyName apsolute or relative name
     * @return relative name
     */
    protected static String relativePropertyName(String propertyName) {
        if (!propertyName.contains(SEPARATOR))
            return propertyName;
        return StringUtils.substringAfterLast(propertyName, SEPARATOR);
    }

    protected static String buildPropertyPrefix(String... parts) {
        if (parts == null || parts.length == 0)
            throw new IllegalArgumentException("Prefix must consist of at least one part");
        if (parts.length == 1)
            return parts[0] + SEPARATOR;

        StringBuilder sb = new StringBuilder();
        for (String part : parts) {
            if (part.isEmpty())
                continue;
            sb.append(part);
            if (!StringBuilderUtils.endsWith(sb, SEPARATOR))
                sb.append(SEPARATOR);
        }
        if (!StringBuilderUtils.endsWith(sb, SEPARATOR))
            sb.append(SEPARATOR);

        return sb.toString();
    }

    protected static final class PropertyPrefixBuilder {

        private final StringBuilder sb = new StringBuilder();

        public PropertyPrefixBuilder() {
        }

        public PropertyPrefixBuilder(String name) {
            sb.append(name);
        }

        public PropertyPrefixBuilder append(String name) {
            sb.append(name);
            if (!StringBuilderUtils.endsWith(sb, SEPARATOR))
                sb.append(SEPARATOR);
            return this;
        }

        public String toPropertyPrefix() {
            return sb.toString();
        }
    }

}