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android get available memory stats

Posted on by Posted in Android

Here is a basic device utility class that list out all device storage info.

  • Available internal memory size.
  • Total internal memory size.
  • Available external memory size.
  • Total external memory size.

Remember to use this utility we need application READ_EXTERNAL_STORAGE .
In code i did not imported required packages as it depends upon your application project packages.

public class DeviceInfoUtil {
 
	Context mContext;
 
 public DeviceInfoUtil(Context mContext) {
	this.mContext = mContext;
 }
 
public long getTotalInternalMemorySize() {
    File path = Environment.getDataDirectory();
    StatFs stat = new StatFs(path.getPath());
    long blockSize = stat.getBlockSize();
    long totalBlocks = stat.getBlockCount();
    return totalBlocks * blockSize;
}
 
public long getAvailableInternalMemorySize() {
    File path = Environment.getDataDirectory();
    StatFs stat = new StatFs(path.getPath());
    long blockSize = stat.getBlockSize();
    long availableBlocks = stat.getAvailableBlocks();
    return availableBlocks * blockSize;
}
 
public long getTotalExternelMemorySize() {
    File path = Environment.getExternalStorageDirectory();
    StatFs stat = new StatFs(path.getPath());
    long blockSize = stat.getBlockSize();
    long totalBlocks = stat.getBlockCount();
    return totalBlocks * blockSize;
}
 
public long getAvailableExternelMemorySize() {
    File path = Environment.getExternalStorageDirectory();
    StatFs stat = new StatFs(path.getPath());
    long blockSize = stat.getBlockSize();
    long availableBlocks = stat.getAvailableBlocks();
    return availableBlocks * blockSize;
}
}

Android Delete Folder Recursively

Posted on by Posted in Android

Here is a small snippet that is helpful for delete a folder on external SD-card of device. Remember you need to add a use permission in manifesto file of application.

uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"

Here is snippet , you can add it to your file utility class in helpers package of your application

public static boolean deleteFile(File file) {
	if (file != null) {
	    if (file.isDirectory()) {
		String[] children = file.list();
		for (int i = 0; i < children.length; i++) {
		    boolean success = deleteFile(new File(file, children[i]));
		    if (!success) {
			return false;
		    }
		}
	    }
	    return file.delete();
	}
	return false;
    }

PHP Random String Generator

Posted on by Posted in PHP/mysql

When we encrypt we need a random string as salt. Here is a small snippet in PHP that generate a random string from alpha numeric characters. 

<?php 
 
function randomString($length) {
	//take all the numbers,small letter,capital letters
	$original_string = array_merge( range('a','z'), range('A', 'Z'),range(0,9));
	//make a string from the characters
	$original_string = implode("", $original_string);
	//shuffle the string and take the sub string from the given length
	return substr(str_shuffle($original_string), 0, $length);
}
?>

htaccess hotlinker

Posted on by Posted in Html

How to stop hotlinking our web assets like images, music , video other files?

I recently i launched my project that will generates funny logo of user’s name , i worked around one week to complete this php script generates the funny logo. After one or two weeks users directly linking their logo to my hosting server ,than downloading and hosting on their server.This is called hotlinking where visitors will use directly from our hosted web assets.

So i want stop this hotlinking from hotlinker with htaccess , thanks to apache htaccess rewrite rules :) .

Here is my small tweak to my htaccess file that prevents hotlinking. 

RewriteEngine on
RewriteCond  %{HTTP_REFERER} !^$
RewriteCond  %{HTTP_REFERER} !^http(s)?://(www.)?maheshchari.com [NC]
RewriteRule  .(jpg|jpeg|png|gif)$ http://www.maheshchari.com/hotlink.jpg [NC,R,L]

In the above code snippet second and third lines are conditions , if the referrer is blank or maheshchari.com we allow images can be linked , if not we replace that images with hotlink.jpg image.

We can do this for not only images ,we can do it for other media files like mp3, video files, doc files also.

Remember:

You must replace the url to image or any doc file corresponding media type file.

You must allow some websites like facebook,google i.e famaous social networking sites, search engins.

for this you can add as many conditions you want like below

RewriteEngine On
RewriteCond %{HTTP_REFERER} ^http://(.+.)?google.com/ [NC,OR]
RewriteCond %{HTTP_REFERER} ^http://(.+.)?yahoo.com/ [NC,OR]
RewriteCond %{HTTP_REFERER} ^http://(.+.)?technorati.com/ [NC]
 
with this method we can find the hotlinker also by redirecting to our mail sender php script the
referrer.