CustomSerializer
Redstone XML-RPC has the ability to add custom serializer classes to convert our model objects to XML-RPC structs.
Here are the steps to adding a new custom serializer. We used to convert objects into HashMaps then allow Redstone to serialize the maps, but this required a two stage conversion which is costly.
- implement XmlRpcCustomSerializer
- getSupportedClass should return the class you can serialize.
- the serialize method should make use of other serializers by calling XmlRpcSerializer.serialize
-
implement XmlRpcCustomSerializer
-
return the class you support from getSupportedClass
-
implement serialize method to append XML-RPC formatted text to the StringBuffer
-
add an entry to
SerializerRegistry.java -
DONE
#!java
/**
* ManagedServerGroupSerializer is a custom serializer for the XMLRPC library.
* It converts an ServerGroup to an XMLRPC <struct>.
* @version $Rev$
* @xmlrpc.doc
* #struct("Server Group")
* #prop("int", "id")
* #prop("string", "name")
* #prop("string", "description")
* #prop("int", "org_id")
* #prop("int", "system_count")
* #struct_end()
*
*/
Every serializer needs to document what it will output in terms of XML-RPC data structures. Look around at other serializers to see the different documentation types. This javadoc is very important as this is how we auto-generate the API docs.
#!java
public class ManagedServerGroupSerializer implements XmlRpcCustomSerializer {
public static final String MAX_MEMBERS = "max_system_count";
public static final String CURRENT_MEMBERS = "system_count";
/** {@inheritDoc} */
public Class getSupportedClass() {
return ManagedServerGroup.class;
}
The getSupportedClass should return the top most class that this serializer can serialize. For instance,
to serialize a List, LinkedList, etc. you'd return Collection.class.
#!java
/**
* Converts a ServerGroup to a XMLRPC <struct> containing the top-
* level fields of the ServerGroup. It serializes the Org as just an ID
* instead of traversing the entire object graph.
* @param value ServerGroup object.
* @param output Buffer to serialize the object to.
* @param builtInSerializer basic XMLRPC serializer
* @throws XmlRpcException thrown if a problem occurs with serializing
* the value.
* @throws IOException thrown if a problem occurs with serializing
* the value.
*/
public void serialize(Object value, Writer output, XmlRpcSerializer builtInSerializer)
throws XmlRpcException, IOException {
ServerGroup sg = (ServerGroup) value;
SerializerHelper serializer = new SerializerHelper(builtInSerializer);
serializer.add("id", sg.getId());
serializer.add("name", sg.getName());
serializer.add("description", sg.getDescription());
serializer.add(CURRENT_MEMBERS, sg.getCurrentMembers());
serializer.add("org_id", sg.getOrg().getId());
serializer.writeTo(output);
}
XmlRpcSerializer.serialize is used to serialize common java.lang objects. The main thing to consider is how far down the object graph to go.
