utils.HelperMethods.java Source code

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Here is the source code for utils.HelperMethods.java

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/*
 * AnyPlace: A free and open Indoor Navigation Service with superb accuracy!
 *
 * Anyplace is a first-of-a-kind indoor information service offering GPS-less
 * localization, navigation and search inside buildings using ordinary smartphones.
 *
 * Author(s): Lambros Petrou
 *
 * Supervisor: Demetrios Zeinalipour-Yazti
 *
 * URL: https://anyplace.cs.ucy.ac.cy
 * Contact: anyplace@cs.ucy.ac.cy
 *
 * Copyright (c) 2016, Data Management Systems Lab (DMSL), University of Cyprus.
 * All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the Software?), to deal in the
 * Software without restriction, including without limitation the rights to use, copy,
 * modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so, subject to the
 * following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED AS IS?, WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 */

package utils;

import com.fasterxml.jackson.databind.node.ObjectNode;
import org.apache.commons.codec.binary.Base64;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.file.Files;
import java.util.HashMap;

public class HelperMethods {

    /**
     * Must process username and password and validate user credentials
     * @param username user's username
     * @param password user's password
     * @return True if valid credentials, false otherwise
     */
    public static boolean checkUserCredentials(String username, String password) {
        return username != null && password != null && username.length() > 0 && password.length() > 0;
    }

    /**
     * Checks for empty or null par and if any of this holds true then an error message is appended inside the ObjectNode.
     * @param par_name The parameter name for the passed in par
     * @param par The actual parameter to check for emptiness or null
     * @param result The ObjectNode into which we will insert an error message if par is empty or null
     * @return True if par is not empty or null, false otherwise
     */
    public static boolean checkEmptyParameter(String par_name, String par, ObjectNode result) {
        if (par == null || par.equals("")) {
            result.put("status", "error");
            result.put("message", "Missing or Invalid parameter [" + par_name + "]");
            return false;
        }
        return true;
    }

    /**
     * Checks for empty or null par and if any of this holds true then an error message is appended inside the ObjectNode.
     * @param par_name The parameter name for the passed in par
     * @param par The actual parameter to check for emptiness or null
     * @param result The ObjectNode into which we will insert an error message if par is empty or null
     * @param fields The HashMap into which we will insert the par passed in with field_name as the key
     * @param field_name The key for the inserted pair inside the HashMap fields
     * @return True if par is not empty or null, false otherwise
     */
    public static boolean checkEmptyParameter(String par_name, String par, ObjectNode result,
            HashMap<String, String> fields, String field_name) {
        if (par == null || par.equals("")) {
            result.put("status", "error");
            result.put("message", "Missing or Invalid parameter [" + par_name + "]");
            return false;
        }
        fields.put(field_name, par);
        return true;
    }

    /**
     * Returns a byte representation for the base 64 string passed in
     * @param base64_in
     * @return byte[] for the base64 string input
     */
    public static byte[] decodeBase64(String base64_in) {
        return Base64.decodeBase64(base64_in.getBytes());
    }

    /**
     * Returns a string representation for the decoded base 64 string passed in
     * @param base64_in
     * @return Decoded String for the base64 string input
     */
    public static String base64ToString(String base64_in) {
        return new String(decodeBase64(base64_in));
    }

    /**
     * Stores the passed in radio map file inside the server's system for later retrieval if needed and offline processing on the server
     * @param file
     * @return
     */
    public static boolean storeRadioMapToServer(File file) {
        String radio_dir = "radio_maps_raw/";
        File dir = new File(radio_dir);
        dir.mkdirs();

        if (!dir.isDirectory() || !dir.canWrite() || !dir.canExecute()) {
            return false;
        }

        String name = "radiomap_" + LPUtils.generateRandomToken() + System.currentTimeMillis();
        File dest_f = new File(radio_dir + name);
        FileOutputStream fout;

        try {
            fout = new FileOutputStream(dest_f);
            Files.copy(file.toPath(), fout);
            fout.close();
        } catch (IOException e) {
            e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
            return false;
        }

        return true;
    }

    /**
     * Deletes the file passed in. If is a directory then it deletes the contents
     * recursively and then the directory itself
     *
     * @param f The file or the directory to delete
     * @throws IOException When an error occurs while deleting a file
     */
    public static void recDeleteDirFile(File f) throws IOException {
        if (f.isFile()) {
            Files.delete(f.toPath());
        } else if (f.isDirectory()) {
            for (File file : f.listFiles()) {
                if (file.isDirectory()) {
                    recDeleteDirFile(file);
                }
                Files.delete(file.toPath());
            }
            Files.delete(f.toPath());
        }
    }

}