You can obtain an instance of ResourceBundle by calling its static getBundle method.
public static ResourceBundle getBundle(java.lang.String baseName)
public static ResourceBundle getBundle(java.lang.String baseName, Locale locale)
For example:
ResourceBundle rb = ResourceBundle.getBundle("MyResources", Locale.US);
This will load the ResourceBundle object with the values in the corresponding properties file.
If a suitable properties file is not found, the ResourceBundle object will use the default properties file, which will be the one whose name equals the base name and has the properties extension. In this case, the default file would be MyResources.properties.
If this file is not found, a java.util.MissingResourceException will be thrown.
To read a value, you use the ResourceBundle class's getString method, passing the key.
public java.lang.String getString(java.lang.String key)
If the entry with the specified key is not found, a java.util.MissingResourceException will be thrown.