com.syrup.storage.InMemoryStorage.java Source code

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Here is the source code for com.syrup.storage.InMemoryStorage.java

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/*
 * Copyright 2002-2006 the original author or authors.
 *
 * 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.syrup.storage;

import java.io.File;
import java.io.FileOutputStream;
import java.util.List;

import org.apache.http.protocol.HTTP;
import org.apache.log4j.Logger;
import org.w3c.dom.Document;

import com.syrup.OrderedMap;
import com.syrup.model.LibraryItem;
import com.syrup.model.PersistableItem;
import com.syrup.model.Project;
import com.syrup.storage.xml.XmlFactory;
import com.syrup.ui.StartUpServlet;

/**
 * In memory implementation to the storage of projects.
 * 
 * @author chad.lafontaine
 */
public class InMemoryStorage implements IStorage {

    private OrderedMap<Project> syrupProjectStore = new OrderedMap<Project>();
    private OrderedMap<LibraryItem> libraryItems = new OrderedMap<LibraryItem>();
    private static Logger logger = Logger.getLogger(InMemoryStorage.class);

    private static InMemoryStorage store = new InMemoryStorage();

    /**
     * 
     * @return
     */
    static InMemoryStorage getInstance() {
        return store;
    }

    /**
     * HACK: this class is supposed to be a singleton but making this public for
     * XML parsing (Digester)
     * 
     * Error is:
     * 
     * Class org.apache.commons.digester.ObjectCreateRule can not access a
     * member of class com.syrup.storage.InMemoryStorage with modifiers
     * "private"
     * 
     * Possible Fix: write/implement objectcreatefactory classes.
     * 
     * Example:
     * 
     * <pre>
     * http://jsp.codefetch.com/example/fr/storefront-source/com/oreilly/struts/storefront/service/memory/StorefrontMemoryDatabase.java?qy=parse+xml
     * </pre>
     */
    public InMemoryStorage() {

    }

    public void deleteEverything() {

        this.syrupProjectStore = new OrderedMap<Project>();
        this.writeMemoryToFile();
    }

    public Project getProjectById(Long id) {
        return syrupProjectStore.get(id);
    }

    public Project saveOrUpdateProject(Project project) {
        PersistableItem item = syrupProjectStore.save(project);
        this.writeMemoryToFile();
        return (Project) item;
    }

    public void deleteProject(Project project) {
        if (project != null) {
            syrupProjectStore.remove(project.getId());
            this.writeMemoryToFile();
        }
    }

    public List<Project> getProjects() {
        return this.syrupProjectStore.getOrderedList();
    }

    /**
     * Every time something gets saved, we write to memory.
     */
    private synchronized void writeMemoryToFile() {
        File f = new File(StartUpServlet.APP_DEFINITIONS);
        try {
            FileOutputStream fop = new FileOutputStream(f);
            XmlFactory g = new XmlFactory();
            Document result = g.getAsDocument(store);
            String fileOutput = XmlFactory.documentToString(result);
            byte[] fileOutputAsBytes = fileOutput.getBytes(HTTP.UTF_8);
            fop.write(fileOutputAsBytes);
            fop.flush();
            fop.close();
        } catch (Exception e) {
            logger.debug("Unable to write file", e);
        }
    }

    @Override
    public LibraryItem getLibraryItemById(Long id) {
        return this.libraryItems.get(id);
    }

    @Override
    public List<LibraryItem> getLibraryItems() {
        return this.libraryItems.getOrderedList();
    }

    @Override
    public LibraryItem saveOrUpdateLibraryItem(LibraryItem libraryItem) {
        PersistableItem item = this.libraryItems.save(libraryItem);
        // No need to write this to file. Memory only. 
        //this.writeMemoryToFile();
        return (LibraryItem) item;
    }

    @Override
    public LibraryItem getLibraryItemByName(String name) {
        LibraryItem libraryItem = null;
        for (LibraryItem item : this.libraryItems.getOrderedList()) {
            if (item.getName().equalsIgnoreCase(name)) {
                libraryItem = item;
                break;
            }
        }

        return libraryItem;
    }

}