com.google.wave.api.impl.OperationSerializer.java Source code

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Here is the source code for com.google.wave.api.impl.OperationSerializer.java

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/* Copyright (c) 2009 Google Inc.
 *
 * 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.google.wave.api.impl;

import com.metaparadigm.jsonrpc.AbstractSerializer;
import com.metaparadigm.jsonrpc.MarshallException;
import com.metaparadigm.jsonrpc.ObjectMatch;
import com.metaparadigm.jsonrpc.SerializerState;
import com.metaparadigm.jsonrpc.UnmarshallException;

import org.json.JSONException;
import org.json.JSONObject;

/**
 * {@link Operation} serializer/deserializer.
 * 
 * @author scovitz@google.com (Seth Covitz)
 */
@SuppressWarnings("unchecked")
public class OperationSerializer extends AbstractSerializer {

    private static final String FIELD_JAVA_CLASS = "javaClass";
    private static final String FIELD_PROPERTY = "property";
    private static final String FIELD_INDEX = "index";
    private static final String FIELD_TYPE = "type";
    private static final String FIELD_BLIP_ID = "blipId";
    private static final String FIELD_WAVELET_ID = "waveletId";
    private static final String FIELD_WAVE_ID = "waveId";
    private static final Class[] SERIALIZABLE_CLASSES = new Class[] { OperationImpl.class };
    private static final Class[] JSON_CLASSES = new Class[] { JSONObject.class };

    @Override
    public Class[] getJSONClasses() {
        return JSON_CLASSES;
    }

    @Override
    public Class[] getSerializableClasses() {
        return SERIALIZABLE_CLASSES;
    }

    @Override
    public Object marshall(SerializerState state, Object o) throws MarshallException {
        if (!(o instanceof Operation)) {
            throw new MarshallException("Object is not of type Operation.");
        }

        JSONObject json = new JSONObject();
        Operation operation = (Operation) o;
        try {
            json.put(FIELD_JAVA_CLASS, OperationImpl.class.getName());
            json.put(FIELD_WAVE_ID, ser.marshall(state, operation.getWaveId()));
            json.put(FIELD_WAVELET_ID, ser.marshall(state, operation.getWaveletId()));
            json.put(FIELD_BLIP_ID, ser.marshall(state, operation.getBlipId()));
            json.put(FIELD_TYPE, operation.getType().toString());
            json.put(FIELD_INDEX, operation.getIndex());
            json.put(FIELD_PROPERTY, ser.marshall(state, operation.getProperty()));
        } catch (JSONException jsonx) {
            throw new MarshallException("Cannot marshall Operation.");
        }

        return json;
    }

    @SuppressWarnings("unused")
    @Override
    public ObjectMatch tryUnmarshall(SerializerState state, Class clazz, Object json) throws UnmarshallException {
        throw new UnsupportedOperationException();
    }

    @Override
    public Object unmarshall(SerializerState state, Class clazz, Object json) throws UnmarshallException {
        if (!Operation.class.isAssignableFrom(clazz)) {
            throw new UnmarshallException(clazz.getName() + " is not assignable from OperationType");
        }

        JSONObject jsonObject = (JSONObject) json;
        Operation operation = null;
        try {
            String waveId = (String) ser.unmarshall(state, String.class, jsonObject.get(FIELD_WAVE_ID));
            String waveletId = (String) ser.unmarshall(state, String.class, jsonObject.get(FIELD_WAVELET_ID));
            String blipId = (String) ser.unmarshall(state, String.class, jsonObject.get(FIELD_BLIP_ID));
            OperationType type = OperationType.valueOf(jsonObject.getString(FIELD_TYPE));
            int index = jsonObject.isNull(FIELD_INDEX) ? -1 : jsonObject.getInt(FIELD_INDEX);
            Object property = jsonObject.isNull(FIELD_PROPERTY) ? null : jsonObject.get(FIELD_PROPERTY);
            operation = new OperationImpl(type, waveId, waveletId, blipId, index, property);
        } catch (JSONException jsonx) {
            throw new UnmarshallException(clazz.getName() + " could not be constructed.");
        }

        return operation;
    }
}