DeviceNetwork.java

/*
*   Copyright 2015 Constant Innovations Inc
*
*    Licensed under the Apache License, Version 2.0 (the "License");
*    you may not use this file except in compliance with the License.
*    You may obtain a copy of the License at
*
*    http://www.apache.org/licenses/LICENSE-2.0
*
*    Unless required by applicable law or agreed to in writing, software
*    distributed under the License is distributed on an "AS IS" BASIS,
*    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*    See the License for the specific language governing permissions and
*    limitations under the License.
*/
package com.constantinnovationsinc.livemultimedia.utilities;
import android.util.Log;

import java.net.InetAddress;
import java.io.*;
import java.net.*;
import java.util.*;

public class DeviceNetwork {
    private static final String TAG = DeviceNetwork.class.getCanonicalName();
    /**
     * Convert byte array to hex string
     * @param bytes the byte to convert
     * @return HexString
     */
    public static String bytesToHex(byte[] bytes) {
        StringBuilder sbuf = new StringBuilder();
        for(int idx: bytes) {
            int intVal = bytes[idx] & 0xff;
            if (intVal < 0x10) sbuf.append("0");
            sbuf.append(Integer.toHexString(intVal).toUpperCase());
        }
        return sbuf.toString();
    }

    /**
     * Get utf8 byte array.
     * @param str to convert
     * @return  array of NULL if error was found
     */
    public static byte[] getUTF8Bytes(String str) {
        try { return str.getBytes("UTF-8"); } catch (Exception ex) { return null; }
    }

    /**
     * Load UTF8withBOM or any ansi text file.
     * @param filename as string
     * @return String
     * @throws java.io.IOException
     */
    public static String loadFileAsString(String filename) throws java.io.IOException {
        final int BUFLEN=1024;
        BufferedInputStream is = new BufferedInputStream(new FileInputStream(filename), BUFLEN);
        try {
            ByteArrayOutputStream baos = new ByteArrayOutputStream(BUFLEN);
            byte[] bytes = new byte[BUFLEN];
            boolean isUTF8=false;
            int read,count=0;
            while((read=is.read(bytes)) != -1) {
                if (count==0 && bytes[0]==(byte)0xEF && bytes[1]==(byte)0xBB && bytes[2]==(byte)0xBF ) {
                    isUTF8=true;
                    baos.write(bytes, 3, read-3); // drop UTF8 bom marker
                } else {
                    baos.write(bytes, 0, read);
                }
                count+=read;
            }
            return isUTF8 ? new String(baos.toByteArray(), "UTF-8") : new String(baos.toByteArray());
        } finally {
            try {
             is.close();
             } catch(Exception ex){
                Log.e(TAG, ex.getMessage());
             }
        }
    }

    /**
     * Returns MAC address of the given interface name.
     * @param interfaceName eth0, wlan0 or NULL=use first interface
     * @return  mac address or empty string
     */
    public static String getMACAddress(String interfaceName) {
        try {
            List<NetworkInterface> interfaces = Collections.list(NetworkInterface.getNetworkInterfaces());
            for (NetworkInterface intf : interfaces) {
                if (interfaceName != null) {
                    if (!intf.getName().equalsIgnoreCase(interfaceName)) continue;
                }
                byte[] mac = intf.getHardwareAddress();
                if (mac == null) return "";
                StringBuilder buf = new StringBuilder();
                for (int idx : mac) {
                    buf.append(String.format("%02X:", mac[idx]));
                }
                if (buf.length() > 0) buf.deleteCharAt(buf.length() - 1);
                return buf.toString();
            }
        } catch (SocketException ex) {
            Log.e(TAG, ex.getMessage());
        }
        return "";
    }


    public static String getLocalIpAddress() {
        try {
            for (Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements();) {
                NetworkInterface intf = en.nextElement();
                for (Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses(); enumIpAddr.hasMoreElements();) {
                    InetAddress inetAddress = enumIpAddr.nextElement();
                    if (!inetAddress.isLoopbackAddress()) {
                        return inetAddress.getHostAddress().toString();
                    }
                }
            }
        } catch (SocketException ex) {
            Log.e(TAG, ex.toString());
        }
        return null;
    }

}