com.pongasoft.kiwidoc.builder.JSONContentHandler.java Source code

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Here is the source code for com.pongasoft.kiwidoc.builder.JSONContentHandler.java

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/*
 * Copyright (c) 2012 Yan Pujante
 *
 * 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.pongasoft.kiwidoc.builder;

import com.pongasoft.kiwidoc.builder.serializer.Serializer;
import com.pongasoft.kiwidoc.builder.serializer.SerializerException;
import com.pongasoft.kiwidoc.model.Model;
import com.pongasoft.kiwidoc.model.resource.Resource;
import com.pongasoft.util.core.annotations.FieldInitializer;
import com.pongasoft.util.core.annotations.ObjectInitializer;
import com.pongasoft.util.io.IOUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.vfs.FileObject;
import org.apache.commons.vfs.FileSystemException;
import org.apache.commons.vfs.NameScope;

import java.io.IOException;
import java.util.Map;

/**
 * This is the generic implementation when there is a serialized version in a json file.
 * 
 * @author yan@pongasoft.com
 */
public class JSONContentHandler extends AbstractContentHandler {
    public static final Log log = LogFactory.getLog(JSONContentHandler.class);

    public static final String CONTENT_FILENAME = "__content.json";

    private Serializer _modelSerializer;

    /**
     * Constructor
     */
    @ObjectInitializer
    public JSONContentHandler() {
    }

    /**
     * Constructor
     */
    @SuppressWarnings("unchecked")
    public JSONContentHandler(ResourceLocator resourceLocator, Serializer modelSerializer) {
        super(resourceLocator);
        _modelSerializer = modelSerializer;
    }

    public Serializer getModelSerializer() {
        return _modelSerializer;
    }

    @FieldInitializer
    public void setModelSerializer(Serializer modelSerializer) {
        _modelSerializer = modelSerializer;
    }

    /**
     * Logic to determine whether a resource exists (depend on implementation).
     *
     * @param resourceFile the file for the content
     * @return <code>true</code> if the content for the given resource exists
     * @throws StoreException
     */
    @Override
    protected boolean doExists(FileObject resourceFile) throws StoreException {
        try {
            return getContentFile(resourceFile).exists();
        } catch (FileSystemException e) {
            throw new StoreException(e);
        }
    }

    /**
     * Loads the content of the given resource.
     *
     * @param resource the resource to load
     * @return the content as an object since it depends on which content is being read (ex: manifest,
     *         library, packages, class) (never <code>null</code>)
     * @throws NoSuchContentException if the content does not exist
     * @throws StoreException         if there is a problem reading the content.
     */
    public Model loadContent(Resource resource) throws NoSuchContentException, StoreException {
        if (resource == null)
            throw new NoSuchContentException(resource);

        @SuppressWarnings("unchecked")
        Model content = deserialize(resource, loadRawContent(resource));

        return content;
    }

    /**
     * Saves the model.
     *
     * @param model the mode to store
     * @return the resource
     * @throws StoreException if there is a problem
     */
    public Resource saveContent(Model model) throws StoreException {
        try {
            @SuppressWarnings("unchecked")
            Object content = _modelSerializer.serialize(model);
            saveContent(content, getContentFile(model.getResource()));
        } catch (IOException e) {
            throw new StoreException(e);
        } catch (SerializerException e) {
            throw new StoreException(e);
        }

        return model.getResource();
    }

    /**
     * Deserialize the raw content: this method simply switches on the file type and dispatches
     * accordingly
     */
    private Model deserialize(Resource resource, Map<String, Object> rawContent) throws StoreException {
        try {
            return (Model) _modelSerializer.deserialize(null, rawContent);
        } catch (SerializerException e) {
            throw new StoreException("for resource " + resource, e);
        }
    }

    /**
     * Loads the content of the given resource.
     *
     * @param resource the resource to load
     * @return the raw content in json format (never <code>null</code>)
     * @throws NoSuchContentException if the content does not exist
     * @throws StoreException         if there is a problem reading the content.
     */
    public Map<String, Object> loadRawContent(Resource resource) throws NoSuchContentException, StoreException {
        if (resource == null)
            throw new NoSuchContentException(resource);

        try {
            FileObject contentFile = getContentFile(resource);
            if (!contentFile.exists())
                throw new NoSuchContentException(resource);
            String content = IOUtils.readContentAsString(contentFile);

            if (log.isDebugEnabled())
                log.debug("Loaded " + resource + " : " + content.length());

            return JsonCodec.fromJsonStringToMap(content);
        } catch (IOException e) {
            throw new StoreException(e);
        }
    }

    private void saveContent(Object content, FileObject location) throws IOException {
        if (content != null && location != null) {
            IOUtils.saveContent(location, JsonCodec.toJsonString(content));
        }
    }

    private FileObject getContentFile(Resource resource) throws StoreException {
        @SuppressWarnings("unchecked")
        FileObject contentFile = getResourceFile(resource);
        try {
            return getContentFile(contentFile);
        } catch (FileSystemException e) {
            throw new StoreException(e);
        }
    }

    private FileObject getContentFile(FileObject contentFile) throws FileSystemException {
        return contentFile.resolveFile(CONTENT_FILENAME, NameScope.CHILD);
    }
}