PropertyResolver.java

/**
 * Copyright (c) Codice Foundation
 * <p>
 * This is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser
 * General Public License as published by the Free Software Foundation, either version 3 of the
 * License, or any later version.
 * <p>
 * This program 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
 * Lesser General Public License for more details. A copy of the GNU Lesser General Public License
 * is distributed along with this program and can be found at
 * <http://www.gnu.org/licenses/lgpl.html>.
 */
package org.codice.ddf.configuration;

import java.util.List;
import java.util.ListIterator;

import org.apache.commons.lang.text.StrSubstitutor;

/**
 * Class holds a string potentially containing variables of the format ${system.prop} and handles
 * resolving those variables by trying to replace them with system properties
 */
public class PropertyResolver {

    private String propertyString;

    public PropertyResolver(String propStr) {
        propertyString = propStr;
    }

    /**
     * Returns the raw string passed in the ctor with any variables it might contain
     *
     * @return
     */
    public String getRawString() {
        return propertyString;
    }

    /**
     * Returns a string with variables replaced by system property values if they exist
     *
     * @return
     */
    public String getResolvedString() {
        return resolveProperties(propertyString);
    }

    /**
     * Returns a string with variables replaced by system property values if they exist
     *
     * @return
     */
    public static String resolveProperties(String str) {
        return StrSubstitutor.replaceSystemProperties(str);
    }

    /**
     * Returns a List with variables replaced by system property values if they exist
     *
     * @return
     */
    public static List<String> resolveProperties(List<String> list) {
        for (final ListIterator<String> i = list.listIterator(); i.hasNext();) {
            final String item = StrSubstitutor.replaceSystemProperties(i.next());
            i.set(item);
        }
        return list;
    }

    /**
     * Returns the resolved string
     *
     * @return
     */
    public String toString() {
        return getResolvedString();
    }
}