org.magdaaproject.utils.serval.RhizomeUtils.java Source code

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Here is the source code for org.magdaaproject.utils.serval.RhizomeUtils.java

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/*
 * Copyright (C) 2012, 2013 The MaGDAA Project
 *
 * This file is part of the MaGDAA Library Software
 *
 * MaGDAA Library Software is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This source code is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this source code; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package org.magdaaproject.utils.serval;

import java.io.File;
import java.io.IOException;
import java.util.Set;

import org.json.JSONException;
import org.json.JSONObject;
import org.magdaaproject.utils.FileUtils;

import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;

/**
 * a utility class which exposes utility methods for interacting with the Rhizome 
 * component of the Serval Mesh software
 */
public class RhizomeUtils {

    /*
     * private class level constants
     */
    private static final boolean sVerboseLog = true;
    private static final String sLogTag = "RhizomeUtils";

    /**
     * share a file using the Rhizome component of the Serval Mesh software
     * 
     * @param context a context used to gain access to system resources
     * @param path the path to the file to share
     * @return true if the request to share the file is successfully sent
     * 
     * @throws IOException if the file to share cannot be found
     */
    public static boolean shareFile(Context context, String path) throws IOException {

        // check on the parameters
        if (context == null) {
            throw new IllegalArgumentException("the context parameter is required");
        }

        if (FileUtils.isFileReadable(path) == false) {
            throw new IOException("unable to access the specified file '" + path + "'");
        }

        // build the intent
        Intent mIntent = new Intent("org.servalproject.rhizome.ADD_FILE");

        mIntent.putExtra("path", path);

        File mManifestFile = getManifestPath(path);

        if (mManifestFile.exists()) {
            // pass in the previous manifest, so rhizome can update it
            mIntent.putExtra("previous_manifest", mManifestFile.getAbsolutePath());
        }

        // ask rhizome to save the new manifest here
        mIntent.putExtra("save_manifest", mManifestFile.getAbsolutePath());

        // ensure a lack of permission doesn't crash the app
        try {
            ComponentName mServiceName = context.getApplicationContext().startService(mIntent);

            if (mServiceName == null) {
                Log.e(sLogTag, "unable to start the required service");
                return false;
            }
        } catch (SecurityException e) {
            Log.e(sLogTag, "security exception thrown when trying to add file to rhizome", e);
            return false;
        }

        // output verbose debug log info
        if (sVerboseLog) {
            Log.v(sLogTag, "file shared using Rhizome, manifest path '" + mManifestFile.getAbsolutePath() + "'");
        }

        return true;
    }

    /**
     * return a file handle for a manifest file derived from the shared file name
     * 
     * @param path the path to the shared file
     * @return a file handle to the manifest file
     */
    public static File getManifestPath(String path) {
        File mManifestPath = new File(path);
        File mManifestFile = new File(mManifestPath.getParent(), ".manifest-" + mManifestPath.getName());
        return mManifestFile;
    }

    /**
     * check to see if a file has a corresponding manifest file stored with it
     * 
     * @param path to the shared file
     * @return true if the manifest exists and can be read otherwise return false;
     */
    public static boolean hasManifest(String path) {

        File mFile = getManifestPath(path);

        try {
            return FileUtils.isFileReadable(mFile.getCanonicalPath());
        } catch (IOException e) {
            return false;
        }
    }

    /**
     * convert a Rhizome bundle into a JSON representation
     * 
     * @param bundle the bundle to convert
     * @return the bundle contents as JSON
     */
    public static String bundleToJson(Bundle bundle) {

        JSONObject mObject = new JSONObject();

        Set<String> mBundleKeys = bundle.keySet();

        for (String mKey : mBundleKeys) {
            try {
                mObject.put(mKey, bundle.get(mKey).toString());
            } catch (JSONException e) {
                Log.e(sLogTag, "unable to add Rhizome bundle element to JSON object", e);
            }
        }

        return mObject.toString();
    }
}