code

by Dost Muhammad Shah on Android, Coding

validate ip address using regex

The code snippet below will check if the passed string is a valid IP address or not .
An Internet Protocol address (IP address) is a numerical label assigned to each device participating in a computer network that uses the Internet Protocol for communication. Read more about IP address here. This snippet will validate IP version 4 addresses.

/**
 * validate IP address
 * @param String IP address to verify
 * @return Boolean result
 */
public static Boolean isIP(String input) {
    if (input!= null && !input.isEmpty()) {
        //Regex
        String regex = "^((25[0-5])|(2[0-4]\\d)|(1\\d\\d)|([1-9]\\d)|\\d)(\\.((25[0-5])|(2[0-4]\\d)|(1\\d\\d)|([1-9]\\d)|\\d)){3}$";
        //check if input matches the regex
        if (text.matches(regex)) {
            // valid ip
            return true;
        } else {
            // invalid ip
            return false;
        }
    }
    // invalid input
    return false;
}
 
by Dost Muhammad Shah on Android, Coding

Android: Call to getLayoutInflater() outside activity

Some times we need the inflater outside activities in android . To get access to the inflator we may use the following code snippet. You can use this outside activities – all you need is to provide a Context:

LayoutInflater inflater = LayoutInflater.from(context);

the from function also checks with assert that you actually get an inflater back and throws an error otherwise – which will be much easier to deal with then a null pointer exception somewhere in the code.

An Alternate way is shown below but I recommend to use the above one:

LayoutInflater inflater = (LayoutInflater) context.getSystemService( Context.LAYOUT_INFLATER_SERVICE );

Then to retrieve your different widgets, you inflate a layout:

View view = inflater.inflate( R.layout.myNewInflatedLayout, null );
Button myButton = (Button) view.findViewById( R.id.myButton );