Problem with & and double quotes in my Android app

in my app I am facing following two problems

1. I am trying to show some text from strings.xml file stored in res/values folder. The problem is whenever I enter the & it shows an error as follows:

   Multiple annotations found at this line:
   - The entity name must immediately follow the '&' in the entity reference.
   - error: Error parsing XML: not well-formed (invalid token)

When I remove it the error gets cleared. how to use such special characters in my app

2. When I click a button in my app it hits an url and in return I am getting an return data as follows

   <img src="http://xxxxxxxxxxxxxxxxxxx/test.php%3Fcode_hash%3Da8c159f35af&amp;guid=ON"/>
   

I want to get this url removing the img src="

I tried using the replacewith("","");

But here I am unable to give the " within the double quotes.

How to solve the above issues?