Changes in Android 4.2.2:

• Play Store downloads now show time left to download.
• Long-pressing Wifi and Bluetooth now toggles them in the notification Quick Settings.
• More secure ADB thanks to the new whitelist.
• BT bug fixes
• Other small updates

So far i found only two new features that most useful for me, the Wifi and Bluetooth toggle via Quick Settings and ADB Whitelist.

Wifi and Bluetooth toggle via Quick Settings

This feature is very usefull for me since i use wifi frequently. I frequently need to disconnect Wifi connection with my pocket wifi to save data usage and sometimes i have to disable and enable the Wifi connection to make the connection works for some bad Wifi connections. For bluetooth i also frequently disable and enable it for transfering photo files with my Blackberry and MacBook. To disable or enable Wifi and bluetooth just long press on their icons until the status changes (on or off).

android quick settings

ADB Whitelist (Secure USB Debugging)

Android debugging, as provided by the Android Debug Bridge (ADB) gives us almost complete control over a device when enabled. This is very usefull for developing or testing an application , but can also be used for other purposes such as install and remove apps, copy files to and from the device and execute shell commands on the device. If you have a rooted device, you have complete control over system files. You can get some applications specific data such as stored password, disable or enable specific settings in an application, disable or crack device lock even log in into your Google account. So even though your device is locked, either using password or face unlock, someone can easily access your device by connecting the usb cable and crack or disable the lock.

In Android 4.2.2, a proper solution  was introduced with the so called ‘secure USB debugging’. With this feature, only hosts explicitly authorized by the user can now connect to the adbd daemon on the device and execute debugging commands. Therefore, if someone tries to connect a device to another one via USB in order to access ADB, they need to first unlock the target device and authorize access from the debug host by clicking ‘OK’ in the confirmation dialog. You can make your decision persistent by checking the ‘Always allow from this computer‘ and debugging will work just as before, as long as you are on the same machine.

android secure debugging (adb whitelist)

mac os x 10.7.5

After doing some searching on Google, i managed to find the solution. There was a discussion on Apple support site, the solution was to update Java/JDK to JDK7. So i downloaded JDK7 and installed it, it really fixed the problem. There is no freezing anymore and it gets faster then before.

One drawback is, Java plugin for Chrome will not work. It is because Chrome is 32 bit browser and it does not support Java 7. So if you are heavily using Chrome with java plugin, it is not recommended to update to Java 7. But if you are already using Java 7 but want to get back to Java 6 (pre-installed with Mac Os) you can follow this guide to restore Java 6.

For example, there is an EditText widget ‘nameEt’ inside an activity, to manually show and hide soft keyboard:

Show

InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);

imm.showSoftInput(nameEt, 0);

Hide

InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);

imm.hideSoftInputFromWindow(nameEt.getWindowToken(), 0);

Make sure to place those codes inside an activity.

Enjoy and Make your Favorite Beats

It’s iPod Nano which lets you to tap on your favorite song track and to start enjoying it . The sound of every song is not only very high not very low, there is a balance which seems perfect for your ears. You are free to browse the songs by genres and artists. The music controls are quick and you can move from one song to another in an instant manner. The best feature of this iPod Nano Music library is Genius which you can use when you want to stay in the mood. Sometimes, you are listening a song and get involve in it such a manner that don’t want to betray and in this situation, you can tap genius. It find other songs that have same rhythm and these can get together in the best manner.A genius playlist can be obtained now.

Big Entertainment on Small Screen

iPod Nano makes it feasible for the users to watch their favorite TV shows, videos, movies, etc on a 2.5 inch Multi-touch display. Movie streaming on this small screen would have the same fun which you get from the big screen. Just tap on movie and get an entry into this small cinema. Video controls such as rewind, pause, forward and play are quite fast. Just tap on any of them and do what you want to do.

It’s fun to Be Wire Less

As you know iPod Nano is designed with Bluetooth 4.0 technology and thus, you are in a position to turn on Bluetooth and paired this device with Bluetooth enabled earphones. Now there is no wire which will come into your way.

Feel Colors of Life

Last but not the least, Apple has designed iPod Nano with 7 different shades. I picked purple one while other choices are yellow, red, white, blue, green and black. When you look at this colorful iPod Nano you can’t stop yourself from praising it. Pick a color of your choice and buy it now for $149

package net.londatiga.android.util;

import java.security.MessageDigest;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class Util {
	private static char[] hexDigits = "0123456789abcdef".toCharArray();

	public static String md5(InputStream is) throws IOException {
		String md5 = "";

		try {
		    byte[] bytes = new byte[4096];
		    int read = 0;
		    MessageDigest digest = MessageDigest.getInstance("MD5");

		    while ((read = is.read(bytes)) != -1) {
		        digest.update(bytes, 0, read);
		    }

		    byte[] messageDigest = digest.digest();

		    StringBuilder sb = new StringBuilder(32);

		    for (byte b : messageDigest) {
		        sb.append(hexDigits[(b >> 4) & 0x0f]);
		        sb.append(hexDigits[b & 0x0f]);
		    }

		    md5 = sb.toString();
		} catch (Exception e) {
			e.printStackTrace();
		}

	    return md5;
	}
}

To get md5 checksum from a file and compare it with original md5:

try {
      String md5Origin	= "";//original file's md5 checksum
	  String filePath   = ""; //fill with the real file path name

	  FileInputStream fis   = new FileInputStream(filePath);
	  String md5Checksum	= Util.md5(fis);

	  if (md5Checksum.equals(md5Origin)) {
		  //file is valid
	  }
} catch (Exception e) {
}

GCM architecture consists of three main components, Android application on mobile device, 3rd-party application server and GCM servers. To send message to Android applications on android devices, 3rd-party application server must send the message to GCM servers and let the GCM servers process and send the message to mobile devices. To learn more on how to setup the project and client application, please refer to GCM documentation that well documented and easy to undersand. GCM accepts two data format, JSON and plain text, but it is recommended to use JSON type for flexibility and easy of use.

To send a message, the application server must issue a POST request to the following url:

https://android.googleapis.com/gcm/send

The request is made up of two parts:

HTTP header, that must contain the following headers:

• Authorization:key=your_api_key
• Content-Type:application/json for JSON data type

HTTP body, which is for JSON data type must contain a string representing  a JSON object with the following fields:

• registration_ids, is a string array of registration IDs. Registration IDs  are sent from android applications on mobile devices and saved in application server database.
• data, is the payload data in array of key-value pair.
• collapse_key (optional), is an arbitrary string that is used to collapse a group of like messages when the device is offline, so that only the last message gets sent to the client.
• time_to_live (optional), time in seconds where the message should be kept on GCM storage if the device is offline
• delay_while_iddle (optional), a flag to indicate the message should not be sent immediately if the device is idle (true or false)

Example request:

Content-Type:application/json
Authorization:key=AIzaSyB-1uEai2WiUapxCs2Q0GZYzPu7Udno5aA

{
  "registration_ids" : ["APA91bHun4MxP5egoKMwt2KZFBaFUH-1RYqx..."],
  "data" : {
    "score" : "1-0", "scorer" : "Ronaldo", "time: "44"
  },
}

To send the above message using PHP, define your api key (line 6), the string array of registration IDs (line 9), the payload data in array of key-value pair (line 12), the HTTP headers which contains api key  (line 18) and the HTTP body content in JSON format, use json_encode function to transform the array into JSON object (line 29). The HTTP request type is POST and we use CURL to send the message to GCM server.

Every request will return a response, which might be success (the message is processed successfully) or rejected by GCM server. More detail on how to process the response can be read on this documention.

PHP code

<?php
//request url
$url    = 'https://android.googleapis.com/gcm/send';

//your api key
$apiKey = 'AIzaSyB-1uEai2WiUapxCs2Q0GZYzPu7Udno5aA';

//registration ids
$registrationIDs = array('APA91bHun4MxP5egoKMwt2KZFBaFUH-1RYqx...');

//payload data
$data   = array('score' => '1-0', 'scorer' => 'Ronaldo', 'time' => '44');

$fields = array('registration_ids' => $registrationIDs,
                'data' => $data);

//http header
$headers = array('Authorization: key=' . $apiKey,
                 'Content-Type: application/json');

//curl connection
$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true );
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($fields));

$result = curl_exec($ch);

curl_close($ch);

echo $result;
?>

But if you have a rooted Jelly Bean, you will be happy because with a few extra command line on Android shell terminal, you can use this feature. Under android shell command line, you can create new user, view list of available users and delete users.

How to use:

• Using adb command, go into android shell terminal using adb shell command
  > adb shell
• Enter root mode by typing su:
  shell@android: /$su
• To create a new user, use commnand: pm create-user <username>
  shell@android: /#pm create-user Guest
• To switch user, press and hold Power Off button
• To view list of available users, use command: pm list-users
  shell@android: /#pm list-users
• To delete a user, use command: pm remove user  <user id>
  shell@android: /#pm remove-user 1
• User id can be found when you view list of users. The number on the left of user name is the user id. For example, UserInfo{1:Guest:0}, user id of user Guest is 1.

Every user has different configuration for each application and also has different Gmail account. It means you can create additional user for use by others (eg.  friend or family) with separated Gmail account. This allow you to limit the access to Play Store if you have Gmail account linked to Credit Card so other user can not buy applications without your permission. The additional users (non primary) also have limited access to Settings menu. They can only access Wifi, Bluetooth, Sound, Display, Security and About menu.

A. Preparation

Samsung USB Driver

If you are under Windows, you have to install Samsung USB Driver first for Windows to recognize your phone properly when connected with usb cable. There are three possible ways to install Samsung USB driver:

1. Samsung USB Driver
2. Samsung Kies
3. Galaxy Nexus Driver

You can choose to use one of the above ways to get Samsung USB driver installed.  You can check the installed driver by opening Windows Device Manager. If the driver has been installed and works properly the window should display something like this (Windows 7):

For Mac OS user, the phone should work by default, no need to install USB driver.

Fastboot

To unlock the phone, you need fastboot executable file. If you have already installed Android SDK, this file can be found under android-sdk-<platform>/platform-tools/ (ex: android-sdk-windows/platform-tools/fastboot.exe), otherwise you can download this tool: GalNexJBRoot.zip. Extract the zip file, you’ll get GalNexJBRoot directory which contains fastboot executable file (for Windows, Mac and Linux), recovery image and SuperSu.

B. Unlock Bootloader

In order to install root or any other ROMs, your phone bootloader must be in unlocked mode. If have already unlocked the bootloader, you can skip this step and go to step C.

• Power off the phone
• Connect the phone with computer using usb cable
• Using command prompt (For Windows users: Start->Run->cmd), go into GalNexJBRoot directory
• Type the following command:
  fastboot oem unlock
  
• ChooseYes on Unlock bootloader confirmation screen by pressing volume up button and execute it by pressing power off button.
  
• The bootloader status LOCKED STATE now becomes UNLOCKED
• Restart the phone

C. Install ClockWorkMod (CWM) Recovery and SuperSU

• Connect the phone with computer using usb cable
• Copy CWM-SuperSU-v0.94.zip file from GalNexJBRoot directory into sdcard
• Power off the phone
• Using command prompt under GalNexJBRoot directory, execute the following command to install recovery:
  fastboot flash recovery recovery-clockwork-touch-6.0.1.0-maguro.img
• Press volume down button to select Recovery mode



• Under recovery menu choose install zip from sdcard
• Then choose zip from sdcard
• Then choose CWM-SuperSU-v0.94.zip
• Then choose Yes – Install CWM-SuperSU-v0.94.zip
• Wait untill installation complete than choose Go Back menu
• Reboot the phone
• Now your phone become rooted and SuperSu app installed.

How to update:

• Download the Android Jelly Bean update zip file.
  For i9020t/i9023: http://www.mediafire.com/?65j61btjxgvio40
  For i9020a: http://www.mediafire.com/?7e1i4kdc7krgi1s
• Rename the file to update.zip (optional)
• Download SuperUser zip file
• Copy the update.zip file and jb_root.zip file into sdcard
• Reboot into bootloader end select Recovery
• On CWM recovery menu, choose install zip from sdcard then choose zip from sdcard
• Choose update.zip file and Yes – Install update.zip on confirmation
• Wait until the installation process finish
• Back to recovery menu then install the jb_root.zip (from install zip from sdcard menu)
• Wait until finish then reboot the phone
• After reboot system will update the phone
• Wait until finish, then you will be on Android 4.1.1 with root access and super user installed.

android jelly bean nexus s

Reference: XDA Dev

1. Go to Settings -> Apps
2. Choose All tab then choose Google Services Framework



3. Click Clear data button then Force stop button



4. Go back to Settings -> About -> System updates
5. You should the Android 4.1.1 OTA update notification.

Note:

It may take more than once attempts to make OTA update appears, so you can repeat the step 1-4 untul the OTA update appears. This trick also can be applied on Galaxy Nexus to get Android Jelly Bean OTA update.

Have a nice  try..;)