Java tutorial
/* * WiFi Analyzer * Copyright (C) 2016 VREM Software Development <VREMSoftwareDevelopment@gmail.com> * * This program 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 program 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 program. If not, see <http://www.gnu.org/licenses/> */ package com.aqnote.app.wifianalyzer.wifi.model; import android.support.annotation.NonNull; import org.apache.commons.lang3.ArrayUtils; import org.apache.commons.lang3.StringUtils; import java.math.BigInteger; import java.net.InetAddress; public final class WiFiUtils { private static final double DISTANCE_MHZ_M = 27.55; private static final int MIN_RSSI = -100; private static final int MAX_RSSI = -55; private static final String QUOTE = "\""; public static double calculateDistance(int frequency, int level) { return Math.pow(10.0, (DISTANCE_MHZ_M - (20 * Math.log10(frequency)) + Math.abs(level)) / 20.0); } public static int calculateSignalLevel(int rssi, int numLevels) { if (rssi <= MIN_RSSI) { return 0; } if (rssi >= MAX_RSSI) { return numLevels - 1; } return (rssi - MIN_RSSI) * (numLevels - 1) / (MAX_RSSI - MIN_RSSI); } public static String convertSSID(@NonNull String SSID) { return StringUtils.removeEnd(StringUtils.removeStart(SSID, QUOTE), QUOTE); } public static String convertIpAddress(int ipAddress) { try { byte[] bytes = BigInteger.valueOf(ipAddress).toByteArray(); ArrayUtils.reverse(bytes); return InetAddress.getByAddress(bytes).getHostAddress(); } catch (Exception e) { return StringUtils.EMPTY; } } }