How to add a file.properties to classpath in NetBeans?

I'm not able to add a custom file.properties to my classpath in NetBeans. This is my root directory: http://ift.tt/1F6KKnR

I created a resources directory where puts all my properties file,

/src/java <-- root classpath folder /src/resources <-- properties file (like dao.properties)

If I put the dao.properties in the root classpath, i'm able to load it: /src/java/dao.properties

If I put the dao.properties in any other subpkg, it will not be found (classpath error)

• /src/java/dao/dao.properties


• /src/java/main/dao.properties


• /src/java/utils/dao.properties

and so on...

The loading of properties is made by using the class provided by Bauke Scholtz:

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package dao;

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

/**
 * This class immediately loads the DAO properties file 'dao.properties'
 * once in memory and provides a constructor which takes the specific key
 * which is to be used as property key prefix of the DAO properties file. 
 * There is a property getter which only returns the property prefixed 
 * with 'specificKey.' and provides the option to indicate whether the 
 * property is mandatory or not.
 *
 * @author BalusC
 * @link http://ift.tt/NWaSLe
 */
public class DAOProperties {

    // Constants ------------------------------------------------------
    private static final String PROPERTIES_FILE = "dao.properties";
    private static final Properties PROPERTIES = new Properties();

    static {
        ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
        InputStream propertiesFile = classLoader.getResourceAsStream(PROPERTIES_FILE);

        if (propertiesFile == null) {
            throw new DAOConfigurationException(
                "Properties file '" + PROPERTIES_FILE + "' is missing in classpath.");
        }

        try {
            PROPERTIES.load(propertiesFile);
        } catch (IOException e) {
            throw new DAOConfigurationException(
                "Cannot load properties file '" + PROPERTIES_FILE + "'.", e);
        }
    }

    // Vars -----------------------------------------------------------
    private String specificKey;

    // Constructors ---------------------------------------------------
    /**
     * Construct a DAOProperties instance for the given specific key which 
     * is to be used as property key prefix of the DAO properties file.
     *
     * @param specificKey The specific key which is to be used as property 
     * key prefix.
     * @throws DAOConfigurationException During class initialization if the
     * DAO properties file is missing in the classpath or cannot be loaded.
     */
    public DAOProperties(String specificKey) throws DAOConfigurationException {
        this.specificKey = specificKey;
    }

    // Actions --------------------------------------------------------
    /**
     * Returns the DAOProperties instance specific property value associated
     * with the given key with the option to indicate whether the property is
     * mandatory or not.
     *
     * @param key The key to be associated with a DAOProperties instance
     * specific value.
     * @param mandatory Sets whether the returned property value should not be
     * null nor empty.
     * @return The DAOProperties instance specific property value associated
     * with the given key.
     * @throws DAOConfigurationException If the returned property value is null
     * or empty while it is mandatory.
     */
    public String getProperty(String key, boolean mandatory) 
            throws DAOConfigurationException {
        String fullKey = specificKey + "." + key;
        String property = PROPERTIES.getProperty(fullKey);

        if (property == null || property.trim().length() == 0) {
            if (mandatory) {
                throw new DAOConfigurationException(
                    "Required property '" + fullKey + "'" + 
                    " is missing in properties file '" + 
                    PROPERTIES_FILE + "'.");
            } else {
                // Make empty value null. Empty Strings are evil.
                property = null;
            }
        }

        return property;
    }
}

Thanks in advance for the support, is the whole day i'm fighting with google and netbeans to find the answer.