title: Java Regex for matching quoted string with escaped quotes
body: <p>I know there are already many questions like mine but I found no answer which works in Java. So I write a new question.</p>
  
  <p>I have text files with content like this:</p>
  
  <pre>
  key1 = "This is a \"test\" text with escapes using '\\' characters";
  key2 = 'It must work with \'single\' quotes and "double" quotes';
  </pre>
  
  <p>I need a regular expression which matches the values in the double-quotes (or single-quotes). This regular expression must support the escaped quotes and escaped backslashes. 
  The regular expression must work with Java standard Pattern/Matcher classes.</p>