org.eclipse.thym.core.internal.util.BundleHttpCacheStorage.java Source code

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Here is the source code for org.eclipse.thym.core.internal.util.BundleHttpCacheStorage.java

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/*******************************************************************************
 * Copyright (c) 2013, 2014 Red Hat, Inc. 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 *    Contributors:
 *        Red Hat Inc. - initial API and implementation and/or initial documentation
 *******************************************************************************/
package org.eclipse.thym.core.internal.util;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

import org.apache.commons.io.FileUtils;
import org.apache.http.client.cache.HttpCacheEntry;
import org.apache.http.client.cache.HttpCacheStorage;
import org.apache.http.client.cache.HttpCacheUpdateCallback;
import org.apache.http.client.cache.HttpCacheUpdateException;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.thym.core.HybridCore;
import org.osgi.framework.Bundle;

/**
 * A cache storage whose back-end is on OSGi bundles data file area.
 * 
 * @author Gorkem Ercan
 *
 */
public class BundleHttpCacheStorage implements HttpCacheStorage {
    public static final String SUBDIR_HTTP_CACHE = "httpCache";
    private File cacheDir;

    public BundleHttpCacheStorage(Bundle bundle) {
        File f = bundle.getDataFile(SUBDIR_HTTP_CACHE);
        if (!f.exists()) {
            f.mkdir();
        }
        cacheDir = f;
    }

    @Override
    public void putEntry(String key, HttpCacheEntry entry) throws IOException {
        ByteArrayOutputStream byteArrayOS = null;
        ObjectOutputStream objectOut = null;

        try {
            File f = getCacheFile(key);
            byteArrayOS = new ByteArrayOutputStream();
            objectOut = new ObjectOutputStream(byteArrayOS);
            objectOut.writeObject(entry);
            objectOut.flush();
            FileUtils.writeByteArrayToFile(f, byteArrayOS.toByteArray());
        } finally {
            if (objectOut != null)
                objectOut.close();
            if (byteArrayOS != null)
                byteArrayOS.close();
        }
    }

    private File getCacheFile(String key) {
        String fileName = Integer.toHexString(key.hashCode());
        File f = new File(cacheDir, fileName);
        return f;
    }

    @Override
    public HttpCacheEntry getEntry(String key) throws IOException {
        File f = getCacheFile(key);
        if (f.exists()) {
            ByteArrayInputStream bais = null;
            ObjectInputStream ois = null;
            HttpCacheEntry entry = null;

            try {
                byte[] bytes = FileUtils.readFileToByteArray(f);
                bais = new ByteArrayInputStream(bytes);
                ois = new ObjectInputStream(bais);
                entry = (HttpCacheEntry) ois.readObject();
            } catch (ClassNotFoundException e) {
                HybridCore.log(IStatus.ERROR, "Missing bundle", e);
            } finally {
                if (ois != null)
                    ois.close();
                if (bais != null)
                    bais.close();
            }
            return entry;
        }
        return null;
    }

    @Override
    public void removeEntry(String key) throws IOException {
        File f = getCacheFile(key);
        FileUtils.deleteQuietly(f);
    }

    @Override
    public void updateEntry(String key, HttpCacheUpdateCallback callback)
            throws IOException, HttpCacheUpdateException {
        HttpCacheEntry existing = getEntry(key);
        HttpCacheEntry updated = callback.update(existing);
        if (updated == null) {
            removeEntry(key);
        } else {
            putEntry(key, updated);
        }
    }
}