listserializer.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: ListSerializer.java,v 1.4.2.2 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.List;
import java.util.AbstractList;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.Vector;
import java.util.Iterator;
import org.json.JSONObject;
import org.json.JSONArray;

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

    private static Class[] _serializableClasses = new Class[]
	{ List.class, ArrayList.class, LinkedList.class, Vector.class };

    private static Class[] _JSONClasses = new Class[]
	{ JSONObject.class };

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

    public boolean canSerialize(Class clazz, Class jsonClazz)
    {
	return (super.canSerialize(clazz, jsonClazz) ||
		((jsonClazz == null || jsonClazz == JSONObject.class) &&
		 List.class.isAssignableFrom(clazz)));
    }

    public ObjectMatch tryUnmarshall(SerializerState state,
				     Class clazz, Object o)
	throws UnmarshallException
    {
	JSONObject jso = (JSONObject)o;
	String java_class = jso.getString("javaClass");
	if(java_class == null)
	    throw new UnmarshallException("no type hint");
	if(!(java_class.equals("java.util.List") ||
	     java_class.equals("java.util.AbstractList") ||
	     java_class.equals("java.util.LinkedList") ||
	     java_class.equals("java.util.ArrayList") ||
	     java_class.equals("java.util.Vector")))
	    throw new UnmarshallException("not a List");
	JSONArray jsonlist = jso.getJSONArray("list");
	if(jsonlist == null)
	    throw new UnmarshallException("list missing");
	int i = 0;
	ObjectMatch m = new ObjectMatch(-1);
	try {
	    for(; i < jsonlist.length(); i++)
		m = ser.tryUnmarshall(state, null, jsonlist.get(i)).max(m);
	} catch (UnmarshallException e) {
	    throw new UnmarshallException
		("element " + i + " " + e.getMessage());
	}
	return m;
    }

    public Object unmarshall(SerializerState state, Class clazz, Object o)
	throws UnmarshallException
    {
	JSONObject jso = (JSONObject)o;
	String java_class = jso.getString("javaClass");
	if(java_class == null)
	    throw new UnmarshallException("no type hint");	
	AbstractList al = null;
	if(java_class.equals("java.util.List") ||
	   java_class.equals("java.util.AbstractList") ||
	   java_class.equals("java.util.ArrayList")) {
	    al = new ArrayList();
	} else if(java_class.equals("java.util.LinkedList")) {
	    al = new LinkedList();
	} else if(java_class.equals("java.util.Vector")) {
	    al = new Vector();
	} else {
	    throw new UnmarshallException("not a List");
	}
	JSONArray jsonlist = jso.getJSONArray("list");
	if(jsonlist == null)
	    throw new UnmarshallException("list missing");
	int i = 0;
	try {
	    for(; i < jsonlist.length(); i++)
		al.add(ser.unmarshall(state, null, jsonlist.get(i)));
	} catch (UnmarshallException e) {
	    throw new UnmarshallException
		("element " + i + " " + e.getMessage());
	}
	return al;
    }

    public Object marshall(SerializerState state, Object o)
	throws MarshallException
    {
	List list = (List)o;
	JSONObject obj = new JSONObject();
	JSONArray arr = new JSONArray();
        if (ser.getMarshallClassHints())
            obj.put("javaClass", o.getClass().getName());
	obj.put("list", arr);
	int index=0;
	try {
	    Iterator i = list.iterator();
	    while(i.hasNext()) {
		arr.put(ser.marshall(state, i.next()));
		index++;
	    }
	} catch (MarshallException e) {
	    throw new MarshallException
		("element " + index + " " + e.getMessage());
	}
	return obj;
    }

}