title: When to use @Singleton annotation of Jersey?
body: <p>I am developing a RESTful Web Service and while reading the Jersey <a href="https://jersey.java.net/documentation/latest/jaxrs-resources.html#d0e1851" rel="noreferrer">documentation</a> I came across an annotation <code>@Singleton</code></p>
  
  <p>In my web service I am mostly returning data based on the unique keys provided as parameter.
  An analogy would be return all the information of a Student when the Student_Id is passed.</p>
  
  <p>So my question is when <code>@Singleton</code> would be suited in such kind of Web Services?</p>
  
  <p>As per documentation for <code>@RequestScoped</code></p>
  
  <blockquote>
    <p>If the resource is used more than one time in the request processing, always the same instance will be used. </p>
  </blockquote>
  
  <p>Then in that case we should not bother to use <code>@Singleton</code> right? </p>
  
  <p>Also what could be the use cases where we have to make a new instance for every request?</p>
  
  <p>I did have a look at <a href="https://stackoverflow.com/questions/2749378/when-to-use-singleton-in-a-jersey-resource">this</a> post but my question was not answered.</p>