Changes between Version 1 and Version 2 of ExampleUsingThirdPartyTypes

Timestamp:

10/09/06 13:57:49 (18 years ago)

Author:

lauer

Comment:

--

ExampleUsingThirdPartyTypes

@@ -1 @@
-See [http://delight.opendfki.de/wiki/ExampleUsingOwnConceteTypes#UsingowntypesinCollectionsandMaps How to use own typed in Collections an Maps].
+== Using Third Party Types in your API ==
+
+Eventually, you want to use third party types in your remote calls. Unfortunately the nice annotation features we saw in [wiki:ExampleUsingOwnConceteTypes] and [wiki:ExampleUsingOwnInterfaceTypes] are not applicable here because you are neither allowed to modify the classes nor makes it sense to add an additional dependency to that type.[[BR]]
+The Delight XML-RPC framework offers a solution to this problem by offering conversion mappings to be declared with the API (of course you can add as many mapping you want):
+
+{{{
+@ConverterMappings( 
+      @Mapping(type=URL.class,converter=URLConverter.class) 
+)
+public interface Api
+{
+    URL getHomepageLocation();
+    void addSite( URL url );
+}
+}}}
+
+We have to define a standalone converter to transfer instances of type URL to a XML-RPC representation and vice versa. 
+Therefor, the converter has to implemente the interface ''ParameterConverter'' to define three methods:
+
+ - getXmlRpcRepresentationType(): states what XML-RPC type will be useed as transport representation
+
+ - createFrom(): takes a XML-RPC representation and creates a corresponding instance of type ''URL''.
+
+ - toXmlRpc(): takes an instance of type ''URL'' and converts it into it's XML-RPC representation.
+
+See the complete class here:
+{{{
+public class URLConverter implements ParameterConverter<URL, String>
+{
+    /** Converter uses XML-RPC type {@value XmlRpc.Type.STRING} as XML-RPC representation.*/
+    public Type getXmlRpcRepresentationType()
+    {
+        return( XmlRpc.Type.STRING );
+    }
+    
+    public URL createFrom( String xmlRepresentation )
+        throws TypeConversionException
+    {
+        URL url = null;
+        try
+        {
+            url = new URL( xmlRepresentation );
+        }
+        catch( MalformedURLException e )
+        {
+            throw( new TypeConversionException( e ) );
+        }
+        return( url );
+    }
+
+    public String toXmlRpc( URL param )
+        throws TypeConversionException
+    {
+        return( param.toExternalForm() );
+    }
+}
+}}}
+
+Now, without having to modify it, the type ''URL'' can be used in XML-RPC calls.
+{{{
+Api remote_api = XmlRpc.createClient( Api.class, "handlerId", host, port );
+
+URL homepageUrl = remote_api.getHomepageLocation();
+InputStream is = homepageUrl.openStream();
+...
+
+remote_api.addSite( new URL( "http://middle.of.nowhere" ) );
+
+...
+}}}
+
+See also: [http://delight.opendfki.de/wiki/ExampleUsingOwnConceteTypes#UsingowntypesinCollectionsandMaps How to use own types contained in Collections an Maps].
+