title: How to get keys and value from object in Java
body: <p>I was wondering how to get KEY and VALUE from object in JAVA</p>
  
  <p>my object is like below</p>
  
  <pre><code>Object obj = [{ index_a = 1, index_b = 2}, { index_a = 3, index_b = 4}]
  </code></pre>
  
  <p>I want to get index_a, 1, index_b, 2, ...</p>