referenceserializer.java

json-rpc是和DWR类似的ajax-rpc实现。我比较细化

/*
 * JSON-RPC-Java - a JSON-RPC to Java Bridge with dynamic invocation
 *
 * $Id: ReferenceSerializer.java,v 1.6.2.2 2006/03/06 12:39:21 mclark Exp $
 *
 * Copyright Metaparadigm Pte. Ltd. 2004.
 * Michael Clark <[e-mail]>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package com.metaparadigm.jsonrpc;

import java.util.logging.Logger;
import org.json.JSONObject;

public class ReferenceSerializer extends AbstractSerializer
{
    private final static long serialVersionUID = 1;

    private final static Logger log =
	Logger.getLogger(ReferenceSerializer.class.getName());

    private JSONRPCBridge bridge;

    private static Class[] _serializableClasses = new Class[] { };
    private static Class[] _JSONClasses = new Class[] { };

    public Class[] getSerializableClasses() { return _serializableClasses; }
    public Class[] getJSONClasses() { return _JSONClasses; }

    public ReferenceSerializer(JSONRPCBridge bridge)
    {
	this.bridge = bridge;
    }

    public boolean canSerialize(Class clazz, Class jsonClazz)
    {
	return (!clazz.isArray() &&
		!clazz.isPrimitive() &&
		!clazz.isInterface() &&
		(bridge.isReference(clazz) ||
		 bridge.isCallableReference(clazz)) &&
		(jsonClazz == null || jsonClazz == JSONObject.class));
    }

    public ObjectMatch tryUnmarshall(SerializerState state,
				     Class clazz, Object o)
	throws UnmarshallException
    {
	return ObjectMatch.OKAY;
    }

    public Object unmarshall(SerializerState state, Class clazz, Object o)
	throws UnmarshallException
    {
	JSONObject jso = (JSONObject)o;
	Object ref = null;
	String json_type = jso.getString("JSONRPCType");
	int object_id = jso.getInt("objectID");
	if(json_type != null && json_type.equals("Reference")) {
	    synchronized (bridge.referenceMap) {
		ref = bridge.referenceMap.get(new Integer(object_id));
	    }
	}
	return ref;
    }

    public Object marshall(SerializerState state, Object o)
	throws MarshallException
    {
	Class clazz = o.getClass();
	Integer identity = new Integer(System.identityHashCode(o));
	if(bridge.isReference(clazz)) {
	    if(ser.isDebug())
		log.fine("marshalling reference to object " +
			 identity + " of class " + clazz.getName());
	    synchronized (bridge.referenceMap) {
		bridge.referenceMap.put(identity, o);
	    }
	    JSONObject jso = new JSONObject();
	    jso.put("JSONRPCType", "Reference");
	    jso.put("javaClass", clazz.getName());
	    jso.put("objectID", identity);
	    return jso;
	} else if (bridge.isCallableReference(clazz)) {
	    if(ser.isDebug())
		log.fine("marshalling callable reference to object " +
			 identity + " of class " + clazz.getName());
	    bridge.registerObject(identity, o);
	    JSONObject jso = new JSONObject();
	    jso.put("JSONRPCType", "CallableReference");
	    jso.put("javaClass", clazz.getName());
	    jso.put("objectID", identity);
	    return jso;
	}
	return null;
    }

}