title: Sending array through POST from React App to Spring Boot
body: <p>I've already seen similar question with no success.
  I need to send a matrix of numbers from a web app (ReactJS) to a Spring Boot controller.</p>
  
  <p>I've tried many combination but it always get error, my payload is:</p>
  
  <pre><code>{"rows":[[7,0,0,6,4,0,0,0,0],[9,4,0,0,0,0,8,0,0],[0,8,6,2,5,0,0,9,0],[0,0,0,0,6,8,7,3,0],[4,0,8,0,2,1,0,0,0],[0,0,3,0,0,0,1,6,4],[0,0,0,0,0,9,6,7,5],[3,9,0,0,8,5,0,1,2],[0,0,5,0,0,4,0,0,0]]}
  </code></pre>
  
  <p>My react code is:</p>
  
  <pre><code>axios.post('http://localhost:8090/api/check', {
          rows: this.props.rows
      })
          .then(function (response) {
              console.log(response);
          })
          .catch(function (error) {
              console.log(error);
          });
  </code></pre>
  
  <p>And my Spring Boot controller is:</p>
  
  <pre><code>@PostMapping(path = "/check")
  @CrossOrigin(origins = "http://localhost:3000")
  public boolean check(@RequestParam(value = "rows") final int[] array, final int row, final int col, final int num) {
      return true;
  }
  </code></pre>
  
  <p>I've already tried to declare <code>@RequestParam(value = "rows[]")</code> or <code>@RequestParam(value = "rows")</code>.
  Rather than <code>@RequestParam(value = "rows") final Object rows</code>.</p>
  
  <p>But it always respond with <strong>error 400 (Bad request)</strong>.</p>
  
  <p>How can I pass a matrix through POST request?</p>
  
  <p>Thanks</p>