4. Creating a Resources Implementation

You can implement the [http://jakarta.apache.org/commons/resources/apidocs/org/apache/commons/resources/Resources.html Resources] and [http://jakarta.apache.org/commons/resources/apidocs/org/apache/commons/resources/ResourcesFactory.html ResourcesFactory] interfaces directly, however, by far the easiest way is to use one of the base implementations provided.

The two base Resources classes are:

• [http://jakarta.apache.org/commons/resources/apidocs/org/apache/commons/resources/ResourcesBase.html ResourcesBase] - implements Resources

  • void:init() - (optional) for initialization processing.
  • Iterator:getKeys() - (required) return the set of keys in this Resources
  • Object:getObject(key, Locale, TimeZone) - (required) retrieve the content for a key/Locale/Timezone

• [http://jakarta.apache.org/commons/resources/apidocs/org/apache/commons/resources/CollectionResourcesBase.html CollectionResourcesBase] - extends ResourcesBase and provides a mechanism for caching a set of *Map*s containing key/value pairs for a Locale.

  • void:init() - (optional) for initialization processing.
  • Map:getLocaleMap(baseUrl, Locale) (required) returns a Map of key/value pairs for a Locale.
    

4.1 ResourcesBase

    public class MyResources extends ResourcesBase {

        private String config;

        public MyResources(String name, config) {
            super(name);
            this.config = config;
        }

        public void init() {
            // do initialization here, if required
        }

        public Iterator getKeys() {
            // must implement this method
        }

        public Object getObject(String key, Locale locale, TimeZone timeZone) {
            // must implement this method
        }

    }

4.2 CollectionsResourcesBase

    public class MyResources extends CollectionsResourcesBase {

        public MyResources(String name, config) {
            super(name, config);
        }

        public void init() {
            // do initialization here, if required
        }

        public Object getLocaleMap(String baseUrl, Locale locale) {
            // must implement this method
        }
    }

4.2 ResourcesFactory

To create a factory for your Resources implementation, extends the [http://jakarta.apache.org/commons/resources/apidocs/org/apache/commons/resources/ResourcesFactoryBase.html ResourcesFactoryBase] ...

    public class MyResourcesFactory extends ResourcesFactoryBase {

        public MyResources() {
            super();
        }

        protected Resources createResources(String name, String config) {
            Resources resources = new MyResources(name);
            Resources res = new PropertyResources(name, config);
            resources.setReturnNull(isReturnNull());
            resources.init();
            return resources;
        }
    }

N.B for implementations to be used in a Web Application there is a [http://jakarta.apache.org/commons/resources/apidocs/org/apache/commons/resources/WebappResourcesFactoryBase.html WebappResourcesFactoryBase] factory which includes a ServletContext property with appropriate read/write methods.