Arquivo .properties usando variavel

application.name = Killer App
application.version = 1.6.2

application.title = ${application.name} ${application.version}

planos.nome.plano=
planos.nome.acao=
planos.nome.responsavel=
planos.nome.lider=
planos.data.ultimo.acompanhamento=
planos.msg.acompanhamento.atrasado=\
Bom dia, \n\n\
O Plano de Ação "${nome.plano}" precisa ter seu andamento informado, mediante acompanhamento inserido via Sistema Planos, na medida/atividade descrita a seguir:\n\n\
"${nome.acao}"\n\
   -Nome do responsávl: ${nome.responsavel}\n\
   -Nome do líder do plano: ${nome.lider} \n\
   -Data do último acompanhamento:  ${data.ultimo.acompanhamento} \n\n\
Para inserir um acompanhamento em uma Medida/Atividade de um Plano de Ação acesse o Sistema Planos, selecione o menu "Planos de Ação" e em seguida o sub-menu "Acompanhamento".\n\n\n\
Atenciosamente,\n\n\
  Coordenadoria de Tecnologia da Informação - COTEC

package br.gov.ce.seplag.cronmail.utils;

import java.io.IOException;
import java.io.InputStream;
import java.util.Hashtable;
import java.util.Properties;
import java.io.Serializable;

public class PropertiesHelper implements Serializable {
    private static final long serialVersionUID = 1533667673359633782L;

    /**
     * Store for each propertie file, a instance of java.util.Properties.
     */
    private Hashtable<String, Properties> propertyFiles = null;
    /**
     * Singleton Instance.
     */
    private static PropertiesHelper instance = null;

    /**
     * Private Constructor, for implementing a singleton pattern.
     */
    private PropertiesHelper() {
    }

    /**
     * Return the instance for the Resource Bundle.
     * @return The singleton instance.
     */
    public static synchronized PropertiesHelper getInstance() {

        if (instance == null) {
            instance = new PropertiesHelper();
        }
        return instance;
    }

    /**
     * Loads the properties file.
     * @param fileName - File name of the property file.
     */
    private void loadPropertiesFile(final String fileName) {

        Properties prop;

        // tests if the properties is null.
        if (propertyFiles == null) {
            propertyFiles = new Hashtable<String, Properties>();
        }

        try {
            // Gets the classloader for the container
            ClassLoader classLoader = Thread.currentThread().getContextClassLoader();

            if (classLoader == null) {
                classLoader = getClass().getClassLoader();
            }
            InputStream input = classLoader.getResourceAsStream(fileName);
            if (input != null) {
                prop = new Properties();

                try {
                    prop.load(input);
                    propertyFiles.put(fileName, prop);

                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * Returns the property name the propery name.
     * @param rscBdlFileName - The property file name.
     * @param propName - The property name.
     * @return - The property value.
     */
    public String getProperty(final String rscBdlFileName, final String propName) {

        Properties prop = null;
        String propValue = null;

        // Verify if the propety file was loaded
        if (propertyFiles == null || propertyFiles.get(rscBdlFileName) == null) {
            loadPropertiesFile(rscBdlFileName);
        }

        if (propertyFiles != null && propertyFiles.get(rscBdlFileName) != null) {
            prop = propertyFiles.get(rscBdlFileName);
            propValue = prop.getProperty(propName);

            if (propValue == null) {
                return "";
            }
        }

        return propValue;
    }
    
    public void setProperty (final String rscBdlFileName, final String propName, final String propValue) {
        Properties prop = null;
        
        // Verify if the propety file was loaded
        if (propertyFiles == null || propertyFiles.get(rscBdlFileName) == null) {
            loadPropertiesFile(rscBdlFileName);
        }
        

        if (propertyFiles != null && propertyFiles.get(rscBdlFileName) != null) {
            prop = propertyFiles.get(rscBdlFileName);
            prop.setProperty(propName, propValue);
        }
    }
}

String configPropertiesFile = "messages.properties";
                PropertiesHelper configProperties = PropertiesHelper.getInstance();

                configProperties.setProperty(configPropertiesFile, "planos.nome.plano", nomePlano.toUpperCase());
                configProperties.setProperty(configPropertiesFile, "planos.nome.acao", nomeAcao.toUpperCase());
                configProperties.setProperty(configPropertiesFile, "planos.nome.responsavel", responsavel.toUpperCase());
                configProperties.setProperty(configPropertiesFile, "planos.nome.lider", nomeLider);
                configProperties.setProperty(configPropertiesFile, "planos.data.ultimo.acompanhamento", dataAuxStr);

                String msgAcompanhamentoAtrasado = configProperties.getProperty(configPropertiesFile, "planos.msg.acompanhamento.atrasado");

Object[] arguments = {
     new Integer(7),
     new Date(System.currentTimeMillis()),
     "a disturbance in the Force"
 };

 String result = MessageFormat.format(
     "At {1,time} on {1,date}, there was {2} on planet {0,number,integer}.",
     arguments);

private void loadPropertiesFile(final String fileName) {

        PropertiesConfiguration prop;

        // tests if the properties is null.
        if (propertyFiles == null) {
            propertyFiles = new Hashtable<String, PropertiesConfiguration>();
        }


        // Gets the classloader for the container
        ClassLoader classLoader = Thread.currentThread().getContextClassLoader();

        if (classLoader == null) {
            classLoader = getClass().getClassLoader();
        }
        InputStream input = classLoader.getResourceAsStream(fileName);
        if (input != null) {
            prop = new PropertiesConfiguration();
            
            try {
                prop.load(input);
            } catch (ConfigurationException ex) {
                Logger.getLogger(PropertiesHelper.class.getName()).log(Level.SEVERE, null, ex);
            }
            
            propertyFiles.put(fileName, prop);
        }
    }