org.pepstock.jem.util.VariableSubstituter.java Source code

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Here is the source code for org.pepstock.jem.util.VariableSubstituter.java

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/**
JEM, the BEE - Job Entry Manager, the Batch Execution Environment
Copyright (C) 2012-2015   Andrea "Stock" Stocchero
This program 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
any later version.
    
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 General Public License for more details.
    
You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
package org.pepstock.jem.util;

import java.util.Properties;
import java.util.Set;

import org.apache.commons.lang3.StringUtils;

/**
 * is a substituter of variables in UNIX format ${var}
 * 
 * @author Andrea "Stock" Stocchero
 * @version 1.3   
 *
 */
public class VariableSubstituter {

    /**
     * To avoid any instatiation
     */
    private VariableSubstituter() {

    }

    /**
     * Substitutes in text all possible variables which are keys of properties
     * 
     * @param text text string to update
     * @param variables list of variables
     * @return text modified and feeded by values of variables
     */
    public static String substitute(String text, Properties variables) {
        // checks if the string to change is null
        // or there are any properties
        if (text == null || variables.isEmpty()) {
            return text;
        }
        // sets return value to initial text
        String returnValue = text;
        // gets variables
        Set<Object> vars = variables.keySet();
        for (Object variable : vars) {
            String key = variable.toString();
            String value = variables.getProperty(key);
            // unix pattern 
            String pattern = "${" + key + "}";
            // to avoid never end loop, checks if value of variable is equal
            // to name of variable
            if (!key.equalsIgnoreCase(pattern)) {
                // replaces variable
                returnValue = StringUtils.replace(returnValue, pattern, value);
            }
        }
        return returnValue;
    }
}