title: get the json data in shiro filter
body: <p>I have a problem .<br />
  The json is posted by clinet using post method and is in request body.<br />
  I want to get the json data in my shiro filter.<br />
  But I didn't find any method to get it.<br />
  Is there any solution? I am using spring boot.</p>
  <h1>Thanks for your help</h1>