Using own concete types

[|Special case: Using own types in Collections and Maps.] Java's type erasure in action!

Server side

public interface Api
{
    Param returnParam();
    
    void passAsParameter( Param p );
}

public class Impl implements Api
{
    public Param returnParam() { return new ParamImpl( ... ); }
    
    void passAsParameter( Param p ) {}
}

To use type Param, we have to make it XML-RPC compliant. We use java annotations and user-defined conversion operations to do this.

• the @XmlRpc annotation declares that type Param uses XML-RPC type ARRAY as transport representation

• The interface {{{Convertable}} declares what specific java type is used for transfer via XML-RPC

• toXmlRpc converts an instance of type Param into its XML-RPC representation

• the constructor creates an instance of type Param back from it's XML-RPC representation

@XmlRpc( type=Type.ARRAY )      
public class Param 
               implements Convertable<Collection<String>>
{
    public Param( Collection<String> xmlRpcRepresentation ) { ... }

    public Collection<String> toXmlRpc() { return ... }
}

Now our type ist XML-RPC compliant! We can register the implementation as usual...

WebServer xmlRpcServer = new WebServer( port );
xmlRpcServer.addHandler( "handlerId", XmlRpcHandlerFactory.createHandlerFor( new Impl() );
xmlRpcServer.start();

Client Side

Our client can be used without any extra statements:

Api remote_api = XmlRpc.createClient( Api.class, "handlerId", host, port );

Param p = remote_api.returnParam();

Param asParam = ...;
remote_api.passAsParameter( asParam );

...

Using own types in Collections and Maps