title: Spring RestTemplate parse JSON object with variable keyname
body: <p>I have a REST API call that returns the following JSON object. I need to parse this with Spring's RestTemplate. The problem is that the first key <code>ISBN:0132856204</code> is variable (the numbers change depending on the book). How would I go about doing this?</p>
  
  <pre><code>{
      "ISBN:0132856204": {
          "publishers": [
              {
                  "name": "Pearson"
              }
          ],
          "pagination": "xxiv, 862p",
          "identifiers": {
              "isbn_13": [
                  "978-0-13-285620-1"
              ],
              "openlibrary": [
                  "OL25617855M"
              ]
          },
          "weight": "1340 grams",
          "title": "Computer networking",
          "url": "https://openlibrary.org/books/OL25617855M/Computer_networking",
          "number_of_pages": 862,
          "cover": {
              "small": "https://covers.openlibrary.org/b/id/7290810-S.jpg",
              "large": "https://covers.openlibrary.org/b/id/7290810-L.jpg",
              "medium": "https://covers.openlibrary.org/b/id/7290810-M.jpg"
          },
          "publish_date": "2013",
          "key": "/books/OL25617855M",
          "authors": [
              {
                  "url": "https://openlibrary.org/authors/OL31244A/James_F._Kurose",
                  "name": "James F. Kurose"
              },
              {
                  "url": "https://openlibrary.org/authors/OL658909A/Keith_W._Ross",
                  "name": "Keith W. Ross"
              }
          ],
          "subtitle": "A Top-Down Approach"
      }
  }
  </code></pre>