Regular Expressions – How to Split a String by Comma and White Space

if(attachmentProperty != null && attachmentProperty.Body != null ) { string attachmentBodyString = attachmentProperty.Body.toString(); //above string populated correctly with attachment content

    List<string> modifiedfileLinesList = new List<string>();
    List<string> fileLinesList = new List<String>();
    while(attachmentBodyString != '')
    {
         fileLinesList.add(attachmentBodyString.substring(0,attachmentBodyString.firstIndexOf('\n')));
         attachmentBodyString = attachmentBodyString.substring(attachmentBodyString.firstIndexOf('\n'), attachmentBodyString.length());
    }

attachmentBodyString.split('\n');

//above split function is throwing an error

//some logic here

}

Ok after no of changes. I finally able to get the correct expression

(?:(?:(?:[a-z]{3,9}:(?://)?)(?:[-;:&=+$,w]+@)?[a-z0-9.-]+|(?:www.|[-;:&=+$??,w]+@)[a-z0-9.-]+)((?:/[+~%/.w-]*)?\\??(?:[-+=&;%@.w]*)#?w*)?)

This will return all the links from String

Code

String myvar = 'raewaferwww.dilyan.co.ukhrewadfea'+
''+
'<span style="color: #5f604b;">'+
'<span style="font: signacondcolumn-book;">'+
'<span style="font-size: 8.0pt;">https://www.merchant.com/store</span>'+
'</span>'+
'</span>'+
'<br>'+
'<a href\'="www.account.com">Account</a>';


String myvar1 = '(?:(?:(?:[a-z]{3,9}:(?://)?)(?:[-;:&=+$,w]+@)?[a-z0-9.-]+|(?:www.|[-;:&=+$??,w]+@)[a-z0-9.-]+)((?:/[+~%/.w-]*)?\\??(?:[-+=&;%@.w]*)#?w*)?)';

// First, instantiate a new Pattern object "MyPattern"
Pattern MyPattern = Pattern.compile(myvar1);

// Then instantiate a new Matcher object "MyMatcher"
Matcher MyMatcher = MyPattern.matcher(myvar);

while (MyMatcher.find()) { 
    System.debug(MyMatcher.group());
}