FileUtilities.java

package com.instructure.canvasapi.utilities;

import android.content.Context;
import android.webkit.MimeTypeMap;

import java.io.*;

/**
 * Created by Josh Ruesch
 *
 * Copyright (c) 2014 Instructure. All rights reserved.
 */

public class FileUtilities {

    public final static String FILE_SUFFIX = ".serializable";
    public final static String FILE_DIRECTORY = "cache";

    /**
     * Converts a serializable object to the specified file.
     * @param context
     * @param cacheFileName
     * @param serializable
     * @return
     */
    public static boolean SerializableToFile(Context context, String cacheFileName, Serializable serializable) {

        if (context == null || cacheFileName == null || serializable == null) {
            return false;
        }
        try {
            cacheFileName += FILE_SUFFIX;

            File f = new File(context.getFilesDir(), FILE_DIRECTORY);
            File file = new File(f, cacheFileName);

            file.getParentFile().mkdirs();
            file.createNewFile();


            //Write to file.
            OutputStream outputStream = new FileOutputStream(file);
            OutputStream buffer = new BufferedOutputStream(outputStream);
            ObjectOutput output = new ObjectOutputStream(buffer);

            output.writeObject(serializable);

            output.flush();
            output.close();
            return true;
        } catch (Exception E) {
            return false;
        }
    }

    /**
     * Delets the cache file with the given name
     * @param context
     * @param cacheFileName
     * @return
     */
    public static boolean DeleteFile(Context context, String cacheFileName){
        if(context == null || cacheFileName == null){
            return false;
        }

        try {
            cacheFileName += FILE_SUFFIX;

            //use buffering
            File f = new File(context.getFilesDir(), FILE_DIRECTORY);
            f.mkdirs();
            File file = new File(f, cacheFileName);

            try {
              return file.delete();
            } finally {
            }
        } catch (Exception E) {
            return false;
        }
    }

    /**
     * Converts a specified file to a serializable object.
     * @param context
     * @param cacheFileName
     * @return
     */
    public static Serializable FileToSerializable(Context context, String cacheFileName) {

        try {
            cacheFileName += FILE_SUFFIX;

            //use buffering
            File f = new File(context.getFilesDir(), FILE_DIRECTORY);
            f.mkdirs();
            File file = new File(f, cacheFileName);

            InputStream fileInputStream = new FileInputStream(file);
            InputStream buffer = new BufferedInputStream(fileInputStream);
            ObjectInput input = new ObjectInputStream(buffer);
            try {
                //deserialize
                return (Serializable)input.readObject();
            } finally {
                input.close();
            }
        } catch (Exception E) {
            return null;
        }
    }


    /**
     * deleteAllFilesInDirectory will RECURSIVELY delete all files/folders in a directory
     * @param startFile
     * @return
     */
    public static boolean deleteAllFilesInDirectory(File startFile)
    {
        try
        {
            //If it's a directory.
            if(startFile.isDirectory())
            {
                //Delete all files inside of it.
                String[] files = startFile.list();
                for(String fileName: files){
                    File file = new File(startFile, fileName);
                    //If it's a directory. recursive.
                    if(file.isDirectory()){
                        deleteAllFilesInDirectory(file);
                    }
                    //It's a file. Delete it.
                    else{
                        file.delete();
                    }
                }
                //Now delete the parent folder.
                startFile.delete();
            }
            //If it's not a directory, delete the file.
            else{
                startFile.delete();
            }
            return true;
        }
        catch(Exception E)
        {
            return false;
        }
    }


    /**
     * getFileExtensionFromMimetype returns what's after the /.
     * For example : image/png returns png.
     *
     * @param mimetype
     * @return
     */
    public static String getFileExtensionFromMimetype(String mimetype) {
        if (mimetype == null) {
            return "";
        } else {
            String[] split = mimetype.split("/");
            return split[split.length - 1];
        }
    }

    public static String getMimeType(String url)
    {
        String type = null;
        String extension = MimeTypeMap.getFileExtensionFromUrl(url);
        if (extension != null) {
            MimeTypeMap mime = MimeTypeMap.getSingleton();
            type = mime.getMimeTypeFromExtension(extension);
        }
        return type;
    }

    public static String kalturaCodeFromMimeType(String mimetype){
        if (mimetype == null) {
            return "0";
        } else {
            String[] split = mimetype.split("/");
            if(split[0].equals("video")){
                return "1";
            } else if(split[0].equals("audio")){
                return "5";
            } else {
                return "0";
            }
        }
    }

    public static String mediaTypeFromKalturaCode(long kalturaCode){
        if (kalturaCode == 1) {
            return "video";
        } else if(kalturaCode == 5){
            return "audio";
        } else {
            return "";
        }
    }
}