title: How to pass list in postman in GET request and get in GetMapping
body: <p>I send a list of id to controller using Postman like this</p>
  
  <pre><code>localhost:8090/test/customer?id=1,2
  </code></pre>
  
  <p>And Controller like this</p>
  
  <pre><code>@GetMapping
  public List&lt;Customer&gt; getCustomerListById(Optional&lt;List&lt;Integer&gt;&gt; customerId){
  
  return getCustomerByIdService.getCustomerById(customerId.get());
  
  }
  </code></pre>
  
  <p>And my CustomerRepo like this</p>
  
  <pre><code>public interface CustomerRepo extends CrudRepository&lt;Customer , Integer&gt;{
  
     public List&lt;Customer&gt; findByCustomerIdIn(List&lt;Integer&gt; customerId);
  
  }
  </code></pre>
  
  <p>But it get error like this</p>
  
  <pre><code>{
  "timestamp": 1528884327211,
  "status": 500,
  "error": "Internal Server Error",
  "exception": "java.util.NoSuchElementException",
  "message": "No value present",
  "path": "/test/customer"
  }
  </code></pre>