title: How to mock response of an external API called from within an internal API integration test
body: <p>I am writing integration tests for an application that uses an internal REST API to perform an action; all Java.<br>
  In the API, there is a POST method that calls upon an external API. In the test, I need to send a request to my API to perform an action.<br>
  The problem is, I do not want to send real requests to the external API when running the integration tests.<br>
  How can I mock the response of the external API call? <br>
  Is there a way I can still send a POST request to my API (mocked or otherwise) within my test, but use a mocked response for the external call performed in the Java POST method?<br></p>